| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | */ |
| 7 | /* eslint-disable no-for-of-loops/no-for-of-loops */ |
| 8 | import type {Rule, Scope} from 'eslint'; |
| 9 | import type { |
| 10 | ArrayExpression, |
| 11 | ArrowFunctionExpression, |
| 12 | CallExpression, |
| 13 | Expression, |
| 14 | FunctionDeclaration, |
| 15 | FunctionExpression, |
| 16 | Identifier, |
| 17 | Node, |
| 18 | Pattern, |
| 19 | PrivateIdentifier, |
| 20 | Super, |
| 21 | VariableDeclarator, |
| 22 | } from 'estree'; |
| 23 | |
| 24 | import {getAdditionalEffectHooksFromSettings} from '../shared/Utils'; |
| 25 | |
| 26 | type DeclaredDependency = { |
| 27 | key: string; |
| 28 | node: Node; |
| 29 | }; |
| 30 | |
| 31 | type Dependency = { |
| 32 | isStable: boolean; |
| 33 | references: Array<Scope.Reference>; |
| 34 | }; |
| 35 | |
| 36 | type DependencyTreeNode = { |
| 37 | isUsed: boolean; // True if used in code |
| 38 | isSatisfiedRecursively: boolean; // True if specified in deps |
| 39 | isSubtreeUsed: boolean; // True if something deeper is used by code |
| 40 | children: Map<string, DependencyTreeNode>; // Nodes for properties |
| 41 | }; |
| 42 | |
| 43 | const rule = { |
| 44 | meta: { |
| 45 | type: 'suggestion', |
| 46 | docs: { |
| 47 | description: |
| 48 | 'verifies the list of dependencies for Hooks like useEffect and similar', |
| 49 | recommended: true, |
| 50 | url: 'https://github.com/facebook/react/issues/14920', |
| 51 | }, |
| 52 | fixable: 'code', |
| 53 | hasSuggestions: true, |
| 54 | schema: [ |
| 55 | { |
| 56 | type: 'object', |
| 57 | additionalProperties: false, |
| 58 | enableDangerousAutofixThisMayCauseInfiniteLoops: false, |
| 59 | properties: { |
| 60 | additionalHooks: { |
| 61 | type: 'string', |
| 62 | }, |
| 63 | enableDangerousAutofixThisMayCauseInfiniteLoops: { |
| 64 | type: 'boolean', |
| 65 | }, |
| 66 | experimental_autoDependenciesHooks: { |
| 67 | type: 'array', |
| 68 | items: { |
| 69 | type: 'string', |
| 70 | }, |
| 71 | }, |
| 72 | requireExplicitEffectDeps: { |
| 73 | type: 'boolean', |
| 74 | }, |
| 75 | }, |
| 76 | }, |
| 77 | ], |
| 78 | }, |
| 79 | create(context: Rule.RuleContext) { |
| 80 | const rawOptions = context.options && context.options[0]; |
| 81 | const settings = context.settings || {}; |
| 82 | |
| 83 | // Parse the `additionalHooks` regex. |
| 84 | // Use rule-level additionalHooks if provided, otherwise fall back to settings |
| 85 | const additionalHooks = |
| 86 | rawOptions && rawOptions.additionalHooks |
| 87 | ? new RegExp(rawOptions.additionalHooks) |
| 88 | : getAdditionalEffectHooksFromSettings(settings); |
| 89 | |
| 90 | const enableDangerousAutofixThisMayCauseInfiniteLoops: boolean = |
| 91 | (rawOptions && |
| 92 | rawOptions.enableDangerousAutofixThisMayCauseInfiniteLoops) || |
| 93 | false; |
| 94 | |
| 95 | const experimental_autoDependenciesHooks: ReadonlyArray<string> = |
| 96 | rawOptions && Array.isArray(rawOptions.experimental_autoDependenciesHooks) |
| 97 | ? rawOptions.experimental_autoDependenciesHooks |
| 98 | : []; |
| 99 | |
| 100 | const requireExplicitEffectDeps: boolean = |
| 101 | (rawOptions && rawOptions.requireExplicitEffectDeps) || false; |
| 102 | |
| 103 | const options = { |
| 104 | additionalHooks, |
| 105 | experimental_autoDependenciesHooks, |
| 106 | enableDangerousAutofixThisMayCauseInfiniteLoops, |
| 107 | requireExplicitEffectDeps, |
| 108 | }; |
| 109 | |
| 110 | function reportProblem(problem: Rule.ReportDescriptor) { |
| 111 | if (enableDangerousAutofixThisMayCauseInfiniteLoops) { |
| 112 | // Used to enable legacy behavior. Dangerous. |
| 113 | // Keep this as an option until major IDEs upgrade (including VSCode FB ESLint extension). |
| 114 | if ( |
| 115 | Array.isArray(problem.suggest) && |
| 116 | problem.suggest.length > 0 && |
| 117 | problem.suggest[0] |
| 118 | ) { |
| 119 | problem.fix = problem.suggest[0].fix; |
| 120 | } |
| 121 | } |
| 122 | context.report(problem); |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * SourceCode that also works down to ESLint 3.0.0 |
| 127 | */ |
| 128 | const getSourceCode = |
| 129 | typeof context.getSourceCode === 'function' |
| 130 | ? () => { |
| 131 | return context.getSourceCode(); |
| 132 | } |
| 133 | : () => { |
| 134 | return context.sourceCode; |
| 135 | }; |
| 136 | /** |
| 137 | * SourceCode#getScope that also works down to ESLint 3.0.0 |
| 138 | */ |
| 139 | const getScope = |
| 140 | typeof context.getScope === 'function' |
| 141 | ? () => { |
| 142 | return context.getScope(); |
| 143 | } |
| 144 | : (node: Node) => { |
| 145 | return context.sourceCode.getScope(node); |
| 146 | }; |
| 147 | |
| 148 | const scopeManager = getSourceCode().scopeManager; |
| 149 | |
| 150 | // Should be shared between visitors. |
| 151 | const setStateCallSites = new WeakMap< |
| 152 | Expression | Super, |
| 153 | Pattern | null | undefined |
| 154 | >(); |
| 155 | const stateVariables = new WeakSet<Identifier>(); |
| 156 | const stableKnownValueCache = new WeakMap<Scope.Variable, boolean>(); |
| 157 | const functionWithoutCapturedValueCache = new WeakMap< |
| 158 | Scope.Variable, |
| 159 | boolean |
| 160 | >(); |
| 161 | const useEffectEventVariables = new WeakSet<Expression>(); |
| 162 | |
| 163 | function memoizeWithWeakMap( |
| 164 | fn: (resolved: Scope.Variable) => boolean, |
| 165 | map: WeakMap<Scope.Variable, boolean>, |
| 166 | ) { |
| 167 | return function (arg: Scope.Variable): boolean { |
| 168 | if (map.has(arg)) { |
| 169 | // to verify cache hits: |
| 170 | // console.log(arg.name) |
| 171 | return map.get(arg)!; |
| 172 | } |
| 173 | const result = fn(arg); |
| 174 | map.set(arg, result); |
| 175 | return result; |
| 176 | }; |
| 177 | } |
| 178 | /** |
| 179 | * Visitor for both function expressions and arrow function expressions. |
| 180 | */ |
| 181 | function visitFunctionWithDependencies( |
| 182 | node: ArrowFunctionExpression | FunctionDeclaration | FunctionExpression, |
| 183 | declaredDependenciesNode: Node | undefined, |
| 184 | reactiveHook: Node, |
| 185 | reactiveHookName: string, |
| 186 | isEffect: boolean, |
| 187 | isAutoDepsHook: boolean, |
| 188 | ): void { |
| 189 | if (isEffect && node.async) { |
| 190 | reportProblem({ |
| 191 | node: node, |
| 192 | message: |
| 193 | `Effect callbacks are synchronous to prevent race conditions. ` + |
| 194 | `Put the async function inside:\n\n` + |
| 195 | 'useEffect(() => {\n' + |
| 196 | ' async function fetchData() {\n' + |
| 197 | ' // You can await here\n' + |
| 198 | ' const response = await MyAPI.getData(someId);\n' + |
| 199 | ' // ...\n' + |
| 200 | ' }\n' + |
| 201 | ' fetchData();\n' + |
| 202 | `}, [someId]); // Or [] if effect doesn't need props or state\n\n` + |
| 203 | 'Learn more about data fetching with Hooks: https://react.dev/link/hooks-data-fetching', |
| 204 | }); |
| 205 | } |
| 206 | |
| 207 | // Get the current scope. |
| 208 | const scope = scopeManager.acquire(node); |
| 209 | if (!scope) { |
| 210 | throw new Error( |
| 211 | 'Unable to acquire scope for the current node. This is a bug in eslint-plugin-react-hooks, please file an issue.', |
| 212 | ); |
| 213 | } |
| 214 | |
| 215 | // Find all our "pure scopes". On every re-render of a component these |
| 216 | // pure scopes may have changes to the variables declared within. So all |
| 217 | // variables used in our reactive hook callback but declared in a pure |
| 218 | // scope need to be listed as dependencies of our reactive hook callback. |
| 219 | // |
| 220 | // According to the rules of React you can't read a mutable value in pure |
| 221 | // scope. We can't enforce this in a lint so we trust that all variables |
| 222 | // declared outside of pure scope are indeed frozen. |
| 223 | const pureScopes = new Set(); |
| 224 | let componentScope: Scope.Scope | null = null; |
| 225 | { |
| 226 | let currentScope = scope.upper; |
| 227 | while (currentScope) { |
| 228 | pureScopes.add(currentScope); |
| 229 | if ( |
| 230 | currentScope.type === 'function' || |
| 231 | // @ts-expect-error incorrect TS types |
| 232 | currentScope.type === 'hook' || |
| 233 | // @ts-expect-error incorrect TS types |
| 234 | currentScope.type === 'component' |
| 235 | ) { |
| 236 | break; |
| 237 | } |
| 238 | currentScope = currentScope.upper; |
| 239 | } |
| 240 | // If there is no parent function scope then there are no pure scopes. |
| 241 | // The ones we've collected so far are incorrect. So don't continue with |
| 242 | // the lint. |
| 243 | if (!currentScope) { |
| 244 | return; |
| 245 | } |
| 246 | componentScope = currentScope; |
| 247 | } |
| 248 | |
| 249 | const isArray = Array.isArray; |
| 250 | |
| 251 | // Next we'll define a few helpers that helps us |
| 252 | // tell if some values don't have to be declared as deps. |
| 253 | |
| 254 | // Some are known to be stable based on Hook calls. |
| 255 | // const [state, setState] = useState() / React.useState() |
| 256 | // ^^^ true for this reference |
| 257 | // const [state, dispatch] = useReducer() / React.useReducer() |
| 258 | // ^^^ true for this reference |
| 259 | // const [state, dispatch] = useActionState() / React.useActionState() |
| 260 | // ^^^ true for this reference |
| 261 | // const ref = useRef() |
| 262 | // ^^^ true for this reference |
| 263 | // const onStuff = useEffectEvent(() => {}) |
| 264 | // ^^^ true for this reference |
| 265 | // False for everything else. |
| 266 | function isStableKnownHookValue(resolved: Scope.Variable): boolean { |
| 267 | if (!isArray(resolved.defs)) { |
| 268 | return false; |
| 269 | } |
| 270 | const def = resolved.defs[0]; |
| 271 | if (def == null) { |
| 272 | return false; |
| 273 | } |
| 274 | // Look for `let stuff = ...` |
| 275 | const defNode: VariableDeclarator = def.node; |
| 276 | if (defNode.type !== 'VariableDeclarator') { |
| 277 | return false; |
| 278 | } |
| 279 | let init = defNode.init; |
| 280 | if (init == null) { |
| 281 | return false; |
| 282 | } |
| 283 | while (init.type === 'TSAsExpression' || init.type === 'AsExpression') { |
| 284 | init = init.expression; |
| 285 | } |
| 286 | // Detect primitive constants |
| 287 | // const foo = 42 |
| 288 | let declaration = defNode.parent; |
| 289 | if (declaration == null && componentScope != null) { |
| 290 | // This might happen if variable is declared after the callback. |
| 291 | // In that case ESLint won't set up .parent refs. |
| 292 | // So we'll set them up manually. |
| 293 | fastFindReferenceWithParent(componentScope.block, def.node.id); |
| 294 | declaration = def.node.parent; |
| 295 | if (declaration == null) { |
| 296 | return false; |
| 297 | } |
| 298 | } |
| 299 | if ( |
| 300 | declaration != null && |
| 301 | 'kind' in declaration && |
| 302 | declaration.kind === 'const' && |
| 303 | init.type === 'Literal' && |
| 304 | (typeof init.value === 'string' || |
| 305 | typeof init.value === 'number' || |
| 306 | init.value === null) |
| 307 | ) { |
| 308 | // Definitely stable |
| 309 | return true; |
| 310 | } |
| 311 | // Detect known Hook calls |
| 312 | // const [_, setState] = useState() |
| 313 | if (init.type !== 'CallExpression') { |
| 314 | return false; |
| 315 | } |
| 316 | let callee: Expression | PrivateIdentifier | Super = init.callee; |
| 317 | // Step into `= React.something` initializer. |
| 318 | if ( |
| 319 | callee.type === 'MemberExpression' && |
| 320 | 'name' in callee.object && |
| 321 | callee.object.name === 'React' && |
| 322 | callee.property != null && |
| 323 | !callee.computed |
| 324 | ) { |
| 325 | callee = callee.property; |
| 326 | } |
| 327 | if (callee.type !== 'Identifier') { |
| 328 | return false; |
| 329 | } |
| 330 | const definitionNode: VariableDeclarator = def.node; |
| 331 | const id = definitionNode.id; |
| 332 | const {name} = callee; |
| 333 | if (name === 'useRef' && id.type === 'Identifier') { |
| 334 | // useRef() return value is stable. |
| 335 | return true; |
| 336 | } else if ( |
| 337 | isUseEffectEventIdentifier(callee) && |
| 338 | id.type === 'Identifier' |
| 339 | ) { |
| 340 | for (const ref of resolved.references) { |
| 341 | // @ts-expect-error These types are not compatible (Reference and Identifier) |
| 342 | if (ref !== id) { |
| 343 | useEffectEventVariables.add(ref.identifier); |
| 344 | } |
| 345 | } |
| 346 | // useEffectEvent() return value is always unstable. |
| 347 | return true; |
| 348 | } else if ( |
| 349 | name === 'useState' || |
| 350 | name === 'useReducer' || |
| 351 | name === 'useActionState' |
| 352 | ) { |
| 353 | // Only consider second value in initializing tuple stable. |
| 354 | if ( |
| 355 | id.type === 'ArrayPattern' && |
| 356 | id.elements.length === 2 && |
| 357 | isArray(resolved.identifiers) |
| 358 | ) { |
| 359 | // Is second tuple value the same reference we're checking? |
| 360 | if (id.elements[1] === resolved.identifiers[0]) { |
| 361 | if (name === 'useState') { |
| 362 | const references = resolved.references; |
| 363 | let writeCount = 0; |
| 364 | for (const reference of references) { |
| 365 | if (reference.isWrite()) { |
| 366 | writeCount++; |
| 367 | } |
| 368 | if (writeCount > 1) { |
| 369 | return false; |
| 370 | } |
| 371 | setStateCallSites.set(reference.identifier, id.elements[0]); |
| 372 | } |
| 373 | } |
| 374 | // Setter is stable. |
| 375 | return true; |
| 376 | } else if (id.elements[0] === resolved.identifiers[0]) { |
| 377 | if (name === 'useState') { |
| 378 | const references = resolved.references; |
| 379 | for (const reference of references) { |
| 380 | stateVariables.add(reference.identifier); |
| 381 | } |
| 382 | } |
| 383 | // State variable itself is dynamic. |
| 384 | return false; |
| 385 | } |
| 386 | } |
| 387 | } else if (name === 'useTransition') { |
| 388 | // Only consider second value in initializing tuple stable. |
| 389 | if ( |
| 390 | id.type === 'ArrayPattern' && |
| 391 | id.elements.length === 2 && |
| 392 | Array.isArray(resolved.identifiers) |
| 393 | ) { |
| 394 | // Is second tuple value the same reference we're checking? |
| 395 | if (id.elements[1] === resolved.identifiers[0]) { |
| 396 | // Setter is stable. |
| 397 | return true; |
| 398 | } |
| 399 | } |
| 400 | } |
| 401 | // By default assume it's dynamic. |
| 402 | return false; |
| 403 | } |
| 404 | |
| 405 | // Some are just functions that don't reference anything dynamic. |
| 406 | function isFunctionWithoutCapturedValues( |
| 407 | resolved: Scope.Variable, |
| 408 | ): boolean { |
| 409 | if (!isArray(resolved.defs)) { |
| 410 | return false; |
| 411 | } |
| 412 | const def = resolved.defs[0]; |
| 413 | if (def == null) { |
| 414 | return false; |
| 415 | } |
| 416 | if (def.node == null || def.node.id == null) { |
| 417 | return false; |
| 418 | } |
| 419 | // Search the direct component subscopes for |
| 420 | // top-level function definitions matching this reference. |
| 421 | const fnNode: Node = def.node; |
| 422 | const childScopes = componentScope?.childScopes || []; |
| 423 | let fnScope = null; |
| 424 | for (const childScope of childScopes) { |
| 425 | const childScopeBlock = childScope.block; |
| 426 | if ( |
| 427 | // function handleChange() {} |
| 428 | (fnNode.type === 'FunctionDeclaration' && |
| 429 | childScopeBlock === fnNode) || |
| 430 | // const handleChange = () => {} |
| 431 | // const handleChange = function() {} |
| 432 | (fnNode.type === 'VariableDeclarator' && |
| 433 | childScopeBlock.parent === fnNode) |
| 434 | ) { |
| 435 | // Found it! |
| 436 | fnScope = childScope; |
| 437 | break; |
| 438 | } |
| 439 | } |
| 440 | if (fnScope == null) { |
| 441 | return false; |
| 442 | } |
| 443 | // Does this function capture any values |
| 444 | // that are in pure scopes (aka render)? |
| 445 | for (const ref of fnScope.through) { |
| 446 | if (ref.resolved == null) { |
| 447 | continue; |
| 448 | } |
| 449 | if ( |
| 450 | pureScopes.has(ref.resolved.scope) && |
| 451 | // Stable values are fine though, |
| 452 | // although we won't check functions deeper. |
| 453 | !memoizedIsStableKnownHookValue(ref.resolved) |
| 454 | ) { |
| 455 | return false; |
| 456 | } |
| 457 | } |
| 458 | // If we got here, this function doesn't capture anything |
| 459 | // from render--or everything it captures is known stable. |
| 460 | return true; |
| 461 | } |
| 462 | |
| 463 | // Remember such values. Avoid re-running extra checks on them. |
| 464 | const memoizedIsStableKnownHookValue = memoizeWithWeakMap( |
| 465 | isStableKnownHookValue, |
| 466 | stableKnownValueCache, |
| 467 | ); |
| 468 | const memoizedIsFunctionWithoutCapturedValues = memoizeWithWeakMap( |
| 469 | isFunctionWithoutCapturedValues, |
| 470 | functionWithoutCapturedValueCache, |
| 471 | ); |
| 472 | |
| 473 | // These are usually mistaken. Collect them. |
| 474 | const currentRefsInEffectCleanup = new Map< |
| 475 | string, |
| 476 | { |
| 477 | reference: Scope.Reference; |
| 478 | dependencyNode: Identifier; |
| 479 | } |
| 480 | >(); |
| 481 | |
| 482 | // Is this reference inside a cleanup function for this effect node? |
| 483 | // We can check by traversing scopes upwards from the reference, and checking |
| 484 | // if the last "return () => " we encounter is located directly inside the effect. |
| 485 | function isInsideEffectCleanup(reference: Scope.Reference): boolean { |
| 486 | let curScope: Scope.Scope | null = reference.from; |
| 487 | let isInReturnedFunction = false; |
| 488 | while (curScope != null && curScope.block !== node) { |
| 489 | if (curScope.type === 'function') { |
| 490 | isInReturnedFunction = |
| 491 | curScope.block.parent != null && |
| 492 | curScope.block.parent.type === 'ReturnStatement'; |
| 493 | } |
| 494 | curScope = curScope.upper; |
| 495 | } |
| 496 | return isInReturnedFunction; |
| 497 | } |
| 498 | |
| 499 | // Get dependencies from all our resolved references in pure scopes. |
| 500 | // Key is dependency string, value is whether it's stable. |
| 501 | const dependencies = new Map<string, Dependency>(); |
| 502 | const optionalChains = new Map<string, boolean>(); |
| 503 | gatherDependenciesRecursively(scope); |
| 504 | |
| 505 | function gatherDependenciesRecursively(currentScope: Scope.Scope): void { |
| 506 | for (const reference of currentScope.references) { |
| 507 | // If this reference is not resolved or it is not declared in a pure |
| 508 | // scope then we don't care about this reference. |
| 509 | if (!reference.resolved) { |
| 510 | continue; |
| 511 | } |
| 512 | if (!pureScopes.has(reference.resolved.scope)) { |
| 513 | continue; |
| 514 | } |
| 515 | |
| 516 | // Narrow the scope of a dependency if it is, say, a member expression. |
| 517 | // Then normalize the narrowed dependency. |
| 518 | const referenceNode = fastFindReferenceWithParent( |
| 519 | node, |
| 520 | reference.identifier, |
| 521 | ); |
| 522 | if (referenceNode == null) { |
| 523 | continue; |
| 524 | } |
| 525 | const dependencyNode = getDependency(referenceNode); |
| 526 | const dependency = analyzePropertyChain( |
| 527 | dependencyNode, |
| 528 | optionalChains, |
| 529 | ); |
| 530 | |
| 531 | // Accessing ref.current inside effect cleanup is bad. |
| 532 | if ( |
| 533 | // We're in an effect... |
| 534 | isEffect && |
| 535 | // ... and this look like accessing .current... |
| 536 | dependencyNode.type === 'Identifier' && |
| 537 | (dependencyNode.parent?.type === 'MemberExpression' || |
| 538 | dependencyNode.parent?.type === 'OptionalMemberExpression') && |
| 539 | !dependencyNode.parent.computed && |
| 540 | dependencyNode.parent.property.type === 'Identifier' && |
| 541 | dependencyNode.parent.property.name === 'current' && |
| 542 | // ...in a cleanup function or below... |
| 543 | isInsideEffectCleanup(reference) |
| 544 | ) { |
| 545 | currentRefsInEffectCleanup.set(dependency, { |
| 546 | reference, |
| 547 | dependencyNode, |
| 548 | }); |
| 549 | } |
| 550 | |
| 551 | if ( |
| 552 | dependencyNode.parent?.type === 'TSTypeQuery' || |
| 553 | dependencyNode.parent?.type === 'TSTypeReference' |
| 554 | ) { |
| 555 | continue; |
| 556 | } |
| 557 | |
| 558 | const def = reference.resolved.defs[0]; |
| 559 | if (def == null) { |
| 560 | continue; |
| 561 | } |
| 562 | // Ignore references to the function itself as it's not defined yet. |
| 563 | if (def.node != null && def.node.init === node.parent) { |
| 564 | continue; |
| 565 | } |
| 566 | // Ignore Flow type parameters |
| 567 | if ( |
| 568 | // @ts-expect-error We don't have flow types |
| 569 | def.type === 'TypeParameter' || |
| 570 | // @ts-expect-error Flow-specific AST node type |
| 571 | dependencyNode.parent?.type === 'GenericTypeAnnotation' |
| 572 | ) { |
| 573 | continue; |
| 574 | } |
| 575 | |
| 576 | // Add the dependency to a map so we can make sure it is referenced |
| 577 | // again in our dependencies array. Remember whether it's stable. |
| 578 | if (!dependencies.has(dependency)) { |
| 579 | const resolved = reference.resolved; |
| 580 | const isStable = |
| 581 | memoizedIsStableKnownHookValue(resolved) || |
| 582 | memoizedIsFunctionWithoutCapturedValues(resolved); |
| 583 | dependencies.set(dependency, { |
| 584 | isStable, |
| 585 | references: [reference], |
| 586 | }); |
| 587 | } else { |
| 588 | dependencies.get(dependency)?.references.push(reference); |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | for (const childScope of currentScope.childScopes) { |
| 593 | gatherDependenciesRecursively(childScope); |
| 594 | } |
| 595 | } |
| 596 | |
| 597 | // Warn about accessing .current in cleanup effects. |
| 598 | currentRefsInEffectCleanup.forEach( |
| 599 | ({reference, dependencyNode}, dependency) => { |
| 600 | const references = reference.resolved?.references || []; |
| 601 | // Is React managing this ref or us? |
| 602 | // Let's see if we can find a .current assignment. |
| 603 | let foundCurrentAssignment = false; |
| 604 | for (const ref of references) { |
| 605 | const {identifier} = ref; |
| 606 | const {parent} = identifier; |
| 607 | if ( |
| 608 | parent != null && |
| 609 | // ref.current |
| 610 | // Note: no need to handle OptionalMemberExpression because it can't be LHS. |
| 611 | parent.type === 'MemberExpression' && |
| 612 | !parent.computed && |
| 613 | parent.property.type === 'Identifier' && |
| 614 | parent.property.name === 'current' && |
| 615 | // ref.current = <something> |
| 616 | parent.parent?.type === 'AssignmentExpression' && |
| 617 | parent.parent.left === parent |
| 618 | ) { |
| 619 | foundCurrentAssignment = true; |
| 620 | break; |
| 621 | } |
| 622 | } |
| 623 | // We only want to warn about React-managed refs. |
| 624 | if (foundCurrentAssignment) { |
| 625 | return; |
| 626 | } |
| 627 | reportProblem({ |
| 628 | // @ts-expect-error We can do better here (dependencyNode.parent has not been type narrowed) |
| 629 | node: dependencyNode.parent.property, |
| 630 | message: |
| 631 | `The ref value '${dependency}.current' will likely have ` + |
| 632 | `changed by the time this effect cleanup function runs. If ` + |
| 633 | `this ref points to a node rendered by React, copy ` + |
| 634 | `'${dependency}.current' to a variable inside the effect, and ` + |
| 635 | `use that variable in the cleanup function.`, |
| 636 | }); |
| 637 | }, |
| 638 | ); |
| 639 | |
| 640 | // Warn about assigning to variables in the outer scope. |
| 641 | // Those are usually bugs. |
| 642 | const staleAssignments = new Set<string>(); |
| 643 | function reportStaleAssignment(writeExpr: Node, key: string): void { |
| 644 | if (staleAssignments.has(key)) { |
| 645 | return; |
| 646 | } |
| 647 | staleAssignments.add(key); |
| 648 | reportProblem({ |
| 649 | node: writeExpr, |
| 650 | message: |
| 651 | `Assignments to the '${key}' variable from inside React Hook ` + |
| 652 | `${getSourceCode().getText(reactiveHook)} will be lost after each ` + |
| 653 | `render. To preserve the value over time, store it in a useRef ` + |
| 654 | `Hook and keep the mutable value in the '.current' property. ` + |
| 655 | `Otherwise, you can move this variable directly inside ` + |
| 656 | `${getSourceCode().getText(reactiveHook)}.`, |
| 657 | }); |
| 658 | } |
| 659 | |
| 660 | // Remember which deps are stable and report bad usage first. |
| 661 | const stableDependencies = new Set<string>(); |
| 662 | dependencies.forEach(({isStable, references}, key) => { |
| 663 | if (isStable) { |
| 664 | stableDependencies.add(key); |
| 665 | } |
| 666 | references.forEach(reference => { |
| 667 | if (reference.writeExpr) { |
| 668 | reportStaleAssignment(reference.writeExpr, key); |
| 669 | } |
| 670 | }); |
| 671 | }); |
| 672 | |
| 673 | if (staleAssignments.size > 0) { |
| 674 | // The intent isn't clear so we'll wait until you fix those first. |
| 675 | return; |
| 676 | } |
| 677 | |
| 678 | if (!declaredDependenciesNode) { |
| 679 | if (isAutoDepsHook) { |
| 680 | return; |
| 681 | } |
| 682 | // Check if there are any top-level setState() calls. |
| 683 | // Those tend to lead to infinite loops. |
| 684 | let setStateInsideEffectWithoutDeps: string | null = null; |
| 685 | dependencies.forEach(({references}, key) => { |
| 686 | if (setStateInsideEffectWithoutDeps) { |
| 687 | return; |
| 688 | } |
| 689 | references.forEach(reference => { |
| 690 | if (setStateInsideEffectWithoutDeps) { |
| 691 | return; |
| 692 | } |
| 693 | |
| 694 | const id = reference.identifier; |
| 695 | const isSetState = setStateCallSites.has(id); |
| 696 | if (!isSetState) { |
| 697 | return; |
| 698 | } |
| 699 | |
| 700 | let fnScope: Scope.Scope | null = reference.from; |
| 701 | while (fnScope != null && fnScope.type !== 'function') { |
| 702 | fnScope = fnScope.upper; |
| 703 | } |
| 704 | const isDirectlyInsideEffect = fnScope?.block === node; |
| 705 | if (isDirectlyInsideEffect) { |
| 706 | // TODO: we could potentially ignore early returns. |
| 707 | setStateInsideEffectWithoutDeps = key; |
| 708 | } |
| 709 | }); |
| 710 | }); |
| 711 | if (setStateInsideEffectWithoutDeps) { |
| 712 | const {suggestedDependencies} = collectRecommendations({ |
| 713 | dependencies, |
| 714 | declaredDependencies: [], |
| 715 | stableDependencies, |
| 716 | externalDependencies: new Set<string>(), |
| 717 | isEffect: true, |
| 718 | }); |
| 719 | reportProblem({ |
| 720 | node: reactiveHook, |
| 721 | message: |
| 722 | `React Hook ${reactiveHookName} contains a call to '${setStateInsideEffectWithoutDeps}'. ` + |
| 723 | `Without a list of dependencies, this can lead to an infinite chain of updates. ` + |
| 724 | `To fix this, pass [` + |
| 725 | suggestedDependencies.join(', ') + |
| 726 | `] as a second argument to the ${reactiveHookName} Hook.`, |
| 727 | suggest: [ |
| 728 | { |
| 729 | desc: `Add dependencies array: [${suggestedDependencies.join( |
| 730 | ', ', |
| 731 | )}]`, |
| 732 | fix(fixer) { |
| 733 | return fixer.insertTextAfter( |
| 734 | node, |
| 735 | `, [${suggestedDependencies.join(', ')}]`, |
| 736 | ); |
| 737 | }, |
| 738 | }, |
| 739 | ], |
| 740 | }); |
| 741 | } |
| 742 | return; |
| 743 | } |
| 744 | if ( |
| 745 | isAutoDepsHook && |
| 746 | declaredDependenciesNode.type === 'Literal' && |
| 747 | declaredDependenciesNode.value === null |
| 748 | ) { |
| 749 | return; |
| 750 | } |
| 751 | |
| 752 | const declaredDependencies: Array<DeclaredDependency> = []; |
| 753 | const externalDependencies = new Set<string>(); |
| 754 | const isArrayExpression = |
| 755 | declaredDependenciesNode.type === 'ArrayExpression'; |
| 756 | const isTSAsArrayExpression = |
| 757 | declaredDependenciesNode.type === 'TSAsExpression' && |
| 758 | declaredDependenciesNode.expression.type === 'ArrayExpression'; |
| 759 | |
| 760 | if (!isArrayExpression && !isTSAsArrayExpression) { |
| 761 | // If the declared dependencies are not an array expression then we |
| 762 | // can't verify that the user provided the correct dependencies. Tell |
| 763 | // the user this in an error. |
| 764 | reportProblem({ |
| 765 | node: declaredDependenciesNode, |
| 766 | message: |
| 767 | `React Hook ${getSourceCode().getText(reactiveHook)} was passed a ` + |
| 768 | 'dependency list that is not an array literal. This means we ' + |
| 769 | "can't statically verify whether you've passed the correct " + |
| 770 | 'dependencies.', |
| 771 | }); |
| 772 | } else { |
| 773 | const arrayExpression = isTSAsArrayExpression |
| 774 | ? declaredDependenciesNode.expression |
| 775 | : declaredDependenciesNode; |
| 776 | |
| 777 | (arrayExpression as ArrayExpression).elements.forEach( |
| 778 | declaredDependencyNode => { |
| 779 | // Skip elided elements. |
| 780 | if (declaredDependencyNode === null) { |
| 781 | return; |
| 782 | } |
| 783 | // If we see a spread element then add a special warning. |
| 784 | if (declaredDependencyNode.type === 'SpreadElement') { |
| 785 | reportProblem({ |
| 786 | node: declaredDependencyNode, |
| 787 | message: |
| 788 | `React Hook ${getSourceCode().getText(reactiveHook)} has a spread ` + |
| 789 | "element in its dependency array. This means we can't " + |
| 790 | "statically verify whether you've passed the " + |
| 791 | 'correct dependencies.', |
| 792 | }); |
| 793 | return; |
| 794 | } |
| 795 | if (useEffectEventVariables.has(declaredDependencyNode)) { |
| 796 | reportProblem({ |
| 797 | node: declaredDependencyNode, |
| 798 | message: |
| 799 | 'Functions returned from `useEffectEvent` must not be included in the dependency array. ' + |
| 800 | `Remove \`${getSourceCode().getText( |
| 801 | declaredDependencyNode, |
| 802 | )}\` from the list.`, |
| 803 | suggest: [ |
| 804 | { |
| 805 | desc: `Remove the dependency \`${getSourceCode().getText( |
| 806 | declaredDependencyNode, |
| 807 | )}\``, |
| 808 | fix(fixer) { |
| 809 | return fixer.removeRange(declaredDependencyNode.range!); |
| 810 | }, |
| 811 | }, |
| 812 | ], |
| 813 | }); |
| 814 | } |
| 815 | // Try to normalize the declared dependency. If we can't then an error |
| 816 | // will be thrown. We will catch that error and report an error. |
| 817 | let declaredDependency; |
| 818 | try { |
| 819 | declaredDependency = analyzePropertyChain( |
| 820 | declaredDependencyNode, |
| 821 | null, |
| 822 | ); |
| 823 | } catch (error: unknown) { |
| 824 | if ( |
| 825 | error instanceof Error && |
| 826 | /Unsupported node type/.test(error.message) |
| 827 | ) { |
| 828 | if (declaredDependencyNode.type === 'Literal') { |
| 829 | if ( |
| 830 | declaredDependencyNode.value && |
| 831 | dependencies.has(declaredDependencyNode.value as string) |
| 832 | ) { |
| 833 | reportProblem({ |
| 834 | node: declaredDependencyNode, |
| 835 | message: |
| 836 | `The ${declaredDependencyNode.raw} literal is not a valid dependency ` + |
| 837 | `because it never changes. ` + |
| 838 | `Did you mean to include ${declaredDependencyNode.value} in the array instead?`, |
| 839 | }); |
| 840 | } else { |
| 841 | reportProblem({ |
| 842 | node: declaredDependencyNode, |
| 843 | message: |
| 844 | `The ${declaredDependencyNode.raw} literal is not a valid dependency ` + |
| 845 | 'because it never changes. You can safely remove it.', |
| 846 | }); |
| 847 | } |
| 848 | } else { |
| 849 | reportProblem({ |
| 850 | node: declaredDependencyNode, |
| 851 | message: |
| 852 | `React Hook ${getSourceCode().getText(reactiveHook)} has a ` + |
| 853 | `complex expression in the dependency array. ` + |
| 854 | 'Extract it to a separate variable so it can be statically checked.', |
| 855 | }); |
| 856 | } |
| 857 | |
| 858 | return; |
| 859 | } else { |
| 860 | throw error; |
| 861 | } |
| 862 | } |
| 863 | |
| 864 | let maybeID = declaredDependencyNode; |
| 865 | while ( |
| 866 | maybeID.type === 'MemberExpression' || |
| 867 | maybeID.type === 'OptionalMemberExpression' || |
| 868 | maybeID.type === 'ChainExpression' |
| 869 | ) { |
| 870 | // @ts-expect-error This can be done better |
| 871 | maybeID = maybeID.object || maybeID.expression.object; |
| 872 | } |
| 873 | const isDeclaredInComponent = !componentScope.through.some( |
| 874 | ref => ref.identifier === maybeID, |
| 875 | ); |
| 876 | |
| 877 | // Add the dependency to our declared dependency map. |
| 878 | declaredDependencies.push({ |
| 879 | key: declaredDependency, |
| 880 | node: declaredDependencyNode, |
| 881 | }); |
| 882 | |
| 883 | if (!isDeclaredInComponent) { |
| 884 | externalDependencies.add(declaredDependency); |
| 885 | } |
| 886 | }, |
| 887 | ); |
| 888 | } |
| 889 | |
| 890 | const { |
| 891 | suggestedDependencies, |
| 892 | unnecessaryDependencies, |
| 893 | missingDependencies, |
| 894 | duplicateDependencies, |
| 895 | } = collectRecommendations({ |
| 896 | dependencies, |
| 897 | declaredDependencies, |
| 898 | stableDependencies, |
| 899 | externalDependencies, |
| 900 | isEffect, |
| 901 | }); |
| 902 | |
| 903 | let suggestedDeps = suggestedDependencies; |
| 904 | |
| 905 | const problemCount = |
| 906 | duplicateDependencies.size + |
| 907 | missingDependencies.size + |
| 908 | unnecessaryDependencies.size; |
| 909 | |
| 910 | if (problemCount === 0) { |
| 911 | // If nothing else to report, check if some dependencies would |
| 912 | // invalidate on every render. |
| 913 | const constructions = scanForConstructions({ |
| 914 | declaredDependencies, |
| 915 | declaredDependenciesNode, |
| 916 | componentScope, |
| 917 | scope, |
| 918 | }); |
| 919 | constructions.forEach( |
| 920 | ({construction, isUsedOutsideOfHook, depType}) => { |
| 921 | const wrapperHook = |
| 922 | depType === 'function' ? 'useCallback' : 'useMemo'; |
| 923 | |
| 924 | const constructionType = |
| 925 | depType === 'function' ? 'definition' : 'initialization'; |
| 926 | |
| 927 | const defaultAdvice = `wrap the ${constructionType} of '${construction.name.name}' in its own ${wrapperHook}() Hook.`; |
| 928 | |
| 929 | const advice = isUsedOutsideOfHook |
| 930 | ? `To fix this, ${defaultAdvice}` |
| 931 | : `Move it inside the ${reactiveHookName} callback. Alternatively, ${defaultAdvice}`; |
| 932 | |
| 933 | const causation = |
| 934 | depType === 'conditional' || depType === 'logical expression' |
| 935 | ? 'could make' |
| 936 | : 'makes'; |
| 937 | |
| 938 | const message = |
| 939 | `The '${construction.name.name}' ${depType} ${causation} the dependencies of ` + |
| 940 | `${reactiveHookName} Hook (at line ${declaredDependenciesNode.loc?.start.line}) ` + |
| 941 | `change on every render. ${advice}`; |
| 942 | |
| 943 | let suggest: Rule.ReportDescriptor['suggest']; |
| 944 | // Only handle the simple case of variable assignments. |
| 945 | // Wrapping function declarations can mess up hoisting. |
| 946 | if ( |
| 947 | isUsedOutsideOfHook && |
| 948 | construction.type === 'Variable' && |
| 949 | // Objects may be mutated after construction, which would make this |
| 950 | // fix unsafe. Functions _probably_ won't be mutated, so we'll |
| 951 | // allow this fix for them. |
| 952 | depType === 'function' |
| 953 | ) { |
| 954 | suggest = [ |
| 955 | { |
| 956 | desc: `Wrap the ${constructionType} of '${construction.name.name}' in its own ${wrapperHook}() Hook.`, |
| 957 | fix(fixer) { |
| 958 | const [before, after] = |
| 959 | wrapperHook === 'useMemo' |
| 960 | ? [`useMemo(() => { return `, '; })'] |
| 961 | : ['useCallback(', ')']; |
| 962 | return [ |
| 963 | // TODO: also add an import? |
| 964 | fixer.insertTextBefore(construction.node.init!, before), |
| 965 | // TODO: ideally we'd gather deps here but it would require |
| 966 | // restructuring the rule code. This will cause a new lint |
| 967 | // error to appear immediately for useCallback. Note we're |
| 968 | // not adding [] because would that changes semantics. |
| 969 | fixer.insertTextAfter(construction.node.init!, after), |
| 970 | ]; |
| 971 | }, |
| 972 | }, |
| 973 | ]; |
| 974 | } |
| 975 | // TODO: What if the function needs to change on every render anyway? |
| 976 | // Should we suggest removing effect deps as an appropriate fix too? |
| 977 | reportProblem({ |
| 978 | // TODO: Why not report this at the dependency site? |
| 979 | node: construction.node, |
| 980 | message, |
| 981 | suggest, |
| 982 | }); |
| 983 | }, |
| 984 | ); |
| 985 | return; |
| 986 | } |
| 987 | |
| 988 | // If we're going to report a missing dependency, |
| 989 | // we might as well recalculate the list ignoring |
| 990 | // the currently specified deps. This can result |
| 991 | // in some extra deduplication. We can't do this |
| 992 | // for effects though because those have legit |
| 993 | // use cases for over-specifying deps. |
| 994 | if (!isEffect && missingDependencies.size > 0) { |
| 995 | suggestedDeps = collectRecommendations({ |
| 996 | dependencies, |
| 997 | declaredDependencies: [], // Pretend we don't know |
| 998 | stableDependencies, |
| 999 | externalDependencies, |
| 1000 | isEffect, |
| 1001 | }).suggestedDependencies; |
| 1002 | } |
| 1003 | |
| 1004 | // Alphabetize the suggestions, but only if deps were already alphabetized. |
| 1005 | function areDeclaredDepsAlphabetized(): boolean { |
| 1006 | if (declaredDependencies.length === 0) { |
| 1007 | return true; |
| 1008 | } |
| 1009 | const declaredDepKeys = declaredDependencies.map(dep => dep.key); |
| 1010 | const sortedDeclaredDepKeys = declaredDepKeys.slice().sort(); |
| 1011 | return declaredDepKeys.join(',') === sortedDeclaredDepKeys.join(','); |
| 1012 | } |
| 1013 | if (areDeclaredDepsAlphabetized()) { |
| 1014 | suggestedDeps.sort(); |
| 1015 | } |
| 1016 | |
| 1017 | // Most of our algorithm deals with dependency paths with optional chaining stripped. |
| 1018 | // This function is the last step before printing a dependency, so now is a good time to |
| 1019 | // check whether any members in our path are always used as optional-only. In that case, |
| 1020 | // we will use ?. instead of . to concatenate those parts of the path. |
| 1021 | function formatDependency(path: string): string { |
| 1022 | const members = path.split('.'); |
| 1023 | let finalPath = ''; |
| 1024 | for (let i = 0; i < members.length; i++) { |
| 1025 | if (i !== 0) { |
| 1026 | const pathSoFar = members.slice(0, i + 1).join('.'); |
| 1027 | const isOptional = optionalChains.get(pathSoFar) === true; |
| 1028 | finalPath += isOptional ? '?.' : '.'; |
| 1029 | } |
| 1030 | finalPath += members[i]; |
| 1031 | } |
| 1032 | return finalPath; |
| 1033 | } |
| 1034 | |
| 1035 | function getWarningMessage( |
| 1036 | deps: Set<string>, |
| 1037 | singlePrefix: string, |
| 1038 | label: string, |
| 1039 | fixVerb: string, |
| 1040 | ): string | null { |
| 1041 | if (deps.size === 0) { |
| 1042 | return null; |
| 1043 | } |
| 1044 | return ( |
| 1045 | (deps.size > 1 ? '' : singlePrefix + ' ') + |
| 1046 | label + |
| 1047 | ' ' + |
| 1048 | (deps.size > 1 ? 'dependencies' : 'dependency') + |
| 1049 | ': ' + |
| 1050 | joinEnglish( |
| 1051 | Array.from(deps) |
| 1052 | .sort() |
| 1053 | .map(name => "'" + formatDependency(name) + "'"), |
| 1054 | ) + |
| 1055 | `. Either ${fixVerb} ${ |
| 1056 | deps.size > 1 ? 'them' : 'it' |
| 1057 | } or remove the dependency array.` |
| 1058 | ); |
| 1059 | } |
| 1060 | |
| 1061 | let extraWarning = ''; |
| 1062 | if (unnecessaryDependencies.size > 0) { |
| 1063 | let badRef: string | null = null; |
| 1064 | Array.from(unnecessaryDependencies.keys()).forEach(key => { |
| 1065 | if (badRef !== null) { |
| 1066 | return; |
| 1067 | } |
| 1068 | if (key.endsWith('.current')) { |
| 1069 | badRef = key; |
| 1070 | } |
| 1071 | }); |
| 1072 | if (badRef !== null) { |
| 1073 | extraWarning = |
| 1074 | ` Mutable values like '${badRef}' aren't valid dependencies ` + |
| 1075 | "because mutating them doesn't re-render the component."; |
| 1076 | } else if (externalDependencies.size > 0) { |
| 1077 | const dep = Array.from(externalDependencies)[0]!; |
| 1078 | // Don't show this warning for things that likely just got moved *inside* the callback |
| 1079 | // because in that case they're clearly not referring to globals. |
| 1080 | if (!scope.set.has(dep)) { |
| 1081 | extraWarning = |
| 1082 | ` Outer scope values like '${dep}' aren't valid dependencies ` + |
| 1083 | `because mutating them doesn't re-render the component.`; |
| 1084 | } |
| 1085 | } |
| 1086 | } |
| 1087 | |
| 1088 | // `props.foo()` marks `props` as a dependency because it has |
| 1089 | // a `this` value. This warning can be confusing. |
| 1090 | // So if we're going to show it, append a clarification. |
| 1091 | if (!extraWarning && missingDependencies.has('props')) { |
| 1092 | const propDep = dependencies.get('props'); |
| 1093 | if (propDep == null) { |
| 1094 | return; |
| 1095 | } |
| 1096 | const refs = propDep.references; |
| 1097 | if (!Array.isArray(refs)) { |
| 1098 | return; |
| 1099 | } |
| 1100 | let isPropsOnlyUsedInMembers = true; |
| 1101 | for (const ref of refs) { |
| 1102 | const id = fastFindReferenceWithParent( |
| 1103 | componentScope.block, |
| 1104 | ref.identifier, |
| 1105 | ); |
| 1106 | if (!id) { |
| 1107 | isPropsOnlyUsedInMembers = false; |
| 1108 | break; |
| 1109 | } |
| 1110 | const parent = id.parent; |
| 1111 | if (parent == null) { |
| 1112 | isPropsOnlyUsedInMembers = false; |
| 1113 | break; |
| 1114 | } |
| 1115 | if ( |
| 1116 | parent.type !== 'MemberExpression' && |
| 1117 | parent.type !== 'OptionalMemberExpression' |
| 1118 | ) { |
| 1119 | isPropsOnlyUsedInMembers = false; |
| 1120 | break; |
| 1121 | } |
| 1122 | } |
| 1123 | if (isPropsOnlyUsedInMembers) { |
| 1124 | extraWarning = |
| 1125 | ` However, 'props' will change when *any* prop changes, so the ` + |
| 1126 | `preferred fix is to destructure the 'props' object outside of ` + |
| 1127 | `the ${reactiveHookName} call and refer to those specific props ` + |
| 1128 | `inside ${getSourceCode().getText(reactiveHook)}.`; |
| 1129 | } |
| 1130 | } |
| 1131 | |
| 1132 | if (!extraWarning && missingDependencies.size > 0) { |
| 1133 | // See if the user is trying to avoid specifying a callable prop. |
| 1134 | // This usually means they're unaware of useCallback. |
| 1135 | let missingCallbackDep: string | null = null; |
| 1136 | missingDependencies.forEach(missingDep => { |
| 1137 | if (missingCallbackDep) { |
| 1138 | return; |
| 1139 | } |
| 1140 | // Is this a variable from top scope? |
| 1141 | const topScopeRef = componentScope.set.get(missingDep); |
| 1142 | const usedDep = dependencies.get(missingDep); |
| 1143 | if ( |
| 1144 | !usedDep?.references || |
| 1145 | usedDep?.references[0]?.resolved !== topScopeRef |
| 1146 | ) { |
| 1147 | return; |
| 1148 | } |
| 1149 | // Is this a destructured prop? |
| 1150 | const def = topScopeRef?.defs[0]; |
| 1151 | if (def == null || def.name == null || def.type !== 'Parameter') { |
| 1152 | return; |
| 1153 | } |
| 1154 | // Was it called in at least one case? Then it's a function. |
| 1155 | let isFunctionCall = false; |
| 1156 | let id: Identifier | undefined; |
| 1157 | for (const reference of usedDep.references) { |
| 1158 | id = reference.identifier; |
| 1159 | if ( |
| 1160 | id != null && |
| 1161 | id.parent != null && |
| 1162 | (id.parent.type === 'CallExpression' || |
| 1163 | id.parent.type === 'OptionalCallExpression') && |
| 1164 | id.parent.callee === id |
| 1165 | ) { |
| 1166 | isFunctionCall = true; |
| 1167 | break; |
| 1168 | } |
| 1169 | } |
| 1170 | if (!isFunctionCall) { |
| 1171 | return; |
| 1172 | } |
| 1173 | // If it's missing (i.e. in component scope) *and* it's a parameter |
| 1174 | // then it is definitely coming from props destructuring. |
| 1175 | // (It could also be props itself but we wouldn't be calling it then.) |
| 1176 | missingCallbackDep = missingDep; |
| 1177 | }); |
| 1178 | if (missingCallbackDep !== null) { |
| 1179 | extraWarning = |
| 1180 | ` If '${missingCallbackDep}' changes too often, ` + |
| 1181 | `find the parent component that defines it ` + |
| 1182 | `and wrap that definition in useCallback.`; |
| 1183 | } |
| 1184 | } |
| 1185 | |
| 1186 | if (!extraWarning && missingDependencies.size > 0) { |
| 1187 | let setStateRecommendation: { |
| 1188 | missingDep: string; |
| 1189 | setter: string; |
| 1190 | form: 'reducer' | 'updater' | 'inlineReducer'; |
| 1191 | } | null = null; |
| 1192 | for (const missingDep of missingDependencies) { |
| 1193 | if (setStateRecommendation !== null) { |
| 1194 | break; |
| 1195 | } |
| 1196 | const usedDep = dependencies.get(missingDep)!; |
| 1197 | const references = usedDep.references; |
| 1198 | let id; |
| 1199 | let maybeCall; |
| 1200 | for (const reference of references) { |
| 1201 | id = reference.identifier; |
| 1202 | maybeCall = id.parent; |
| 1203 | // Try to see if we have setState(someExpr(missingDep)). |
| 1204 | while (maybeCall != null && maybeCall !== componentScope.block) { |
| 1205 | if (maybeCall.type === 'CallExpression') { |
| 1206 | const correspondingStateVariable = setStateCallSites.get( |
| 1207 | maybeCall.callee, |
| 1208 | ); |
| 1209 | if (correspondingStateVariable != null) { |
| 1210 | if ( |
| 1211 | 'name' in correspondingStateVariable && |
| 1212 | correspondingStateVariable.name === missingDep |
| 1213 | ) { |
| 1214 | // setCount(count + 1) |
| 1215 | setStateRecommendation = { |
| 1216 | missingDep, |
| 1217 | setter: |
| 1218 | 'name' in maybeCall.callee ? maybeCall.callee.name : '', |
| 1219 | form: 'updater', |
| 1220 | }; |
| 1221 | } else if (stateVariables.has(id)) { |
| 1222 | // setCount(count + increment) |
| 1223 | setStateRecommendation = { |
| 1224 | missingDep, |
| 1225 | setter: |
| 1226 | 'name' in maybeCall.callee ? maybeCall.callee.name : '', |
| 1227 | form: 'reducer', |
| 1228 | }; |
| 1229 | } else { |
| 1230 | const resolved = reference.resolved; |
| 1231 | if (resolved != null) { |
| 1232 | // If it's a parameter *and* a missing dep, |
| 1233 | // it must be a prop or something inside a prop. |
| 1234 | // Therefore, recommend an inline reducer. |
| 1235 | const def = resolved.defs[0]; |
| 1236 | if (def != null && def.type === 'Parameter') { |
| 1237 | setStateRecommendation = { |
| 1238 | missingDep, |
| 1239 | setter: |
| 1240 | 'name' in maybeCall.callee |
| 1241 | ? maybeCall.callee.name |
| 1242 | : '', |
| 1243 | form: 'inlineReducer', |
| 1244 | }; |
| 1245 | } |
| 1246 | } |
| 1247 | } |
| 1248 | break; |
| 1249 | } |
| 1250 | } |
| 1251 | maybeCall = maybeCall.parent; |
| 1252 | } |
| 1253 | if (setStateRecommendation !== null) { |
| 1254 | break; |
| 1255 | } |
| 1256 | } |
| 1257 | } |
| 1258 | if (setStateRecommendation !== null) { |
| 1259 | switch (setStateRecommendation.form) { |
| 1260 | case 'reducer': |
| 1261 | extraWarning = |
| 1262 | ` You can also replace multiple useState variables with useReducer ` + |
| 1263 | `if '${setStateRecommendation.setter}' needs the ` + |
| 1264 | `current value of '${setStateRecommendation.missingDep}'.`; |
| 1265 | break; |
| 1266 | case 'inlineReducer': |
| 1267 | extraWarning = |
| 1268 | ` If '${setStateRecommendation.setter}' needs the ` + |
| 1269 | `current value of '${setStateRecommendation.missingDep}', ` + |
| 1270 | `you can also switch to useReducer instead of useState and ` + |
| 1271 | `read '${setStateRecommendation.missingDep}' in the reducer.`; |
| 1272 | break; |
| 1273 | case 'updater': |
| 1274 | extraWarning = |
| 1275 | ` You can also do a functional update '${ |
| 1276 | setStateRecommendation.setter |
| 1277 | }(${setStateRecommendation.missingDep.slice( |
| 1278 | 0, |
| 1279 | 1, |
| 1280 | )} => ...)' if you only need '${ |
| 1281 | setStateRecommendation.missingDep |
| 1282 | }'` + ` in the '${setStateRecommendation.setter}' call.`; |
| 1283 | break; |
| 1284 | default: |
| 1285 | throw new Error('Unknown case.'); |
| 1286 | } |
| 1287 | } |
| 1288 | } |
| 1289 | |
| 1290 | reportProblem({ |
| 1291 | node: declaredDependenciesNode, |
| 1292 | message: |
| 1293 | `React Hook ${getSourceCode().getText(reactiveHook)} has ` + |
| 1294 | // To avoid a long message, show the next actionable item. |
| 1295 | (getWarningMessage(missingDependencies, 'a', 'missing', 'include') || |
| 1296 | getWarningMessage( |
| 1297 | unnecessaryDependencies, |
| 1298 | 'an', |
| 1299 | 'unnecessary', |
| 1300 | 'exclude', |
| 1301 | ) || |
| 1302 | getWarningMessage( |
| 1303 | duplicateDependencies, |
| 1304 | 'a', |
| 1305 | 'duplicate', |
| 1306 | 'omit', |
| 1307 | )) + |
| 1308 | extraWarning, |
| 1309 | suggest: [ |
| 1310 | { |
| 1311 | desc: `Update the dependencies array to be: [${suggestedDeps |
| 1312 | .map(formatDependency) |
| 1313 | .join(', ')}]`, |
| 1314 | fix(fixer) { |
| 1315 | // TODO: consider preserving the comments or formatting? |
| 1316 | return fixer.replaceText( |
| 1317 | declaredDependenciesNode, |
| 1318 | `[${suggestedDeps.map(formatDependency).join(', ')}]`, |
| 1319 | ); |
| 1320 | }, |
| 1321 | }, |
| 1322 | ], |
| 1323 | }); |
| 1324 | } |
| 1325 | |
| 1326 | function visitCallExpression(node: CallExpression): void { |
| 1327 | const callbackIndex = getReactiveHookCallbackIndex(node.callee, options); |
| 1328 | if (callbackIndex === -1) { |
| 1329 | // Not a React Hook call that needs deps. |
| 1330 | return; |
| 1331 | } |
| 1332 | let callback = node.arguments[callbackIndex]; |
| 1333 | const reactiveHook = node.callee; |
| 1334 | const nodeWithoutNamespace = getNodeWithoutReactNamespace(reactiveHook); |
| 1335 | const reactiveHookName = |
| 1336 | 'name' in nodeWithoutNamespace ? nodeWithoutNamespace.name : ''; |
| 1337 | const maybeNode = node.arguments[callbackIndex + 1]; |
| 1338 | const declaredDependenciesNode = |
| 1339 | maybeNode && |
| 1340 | !(maybeNode.type === 'Identifier' && maybeNode.name === 'undefined') |
| 1341 | ? maybeNode |
| 1342 | : undefined; |
| 1343 | const isEffect = /Effect($|[^a-z])/g.test(reactiveHookName); |
| 1344 | |
| 1345 | // Check whether a callback is supplied. If there is no callback supplied |
| 1346 | // then the hook will not work and React will throw a TypeError. |
| 1347 | // So no need to check for dependency inclusion. |
| 1348 | if (!callback) { |
| 1349 | reportProblem({ |
| 1350 | node: reactiveHook, |
| 1351 | message: |
| 1352 | `React Hook ${reactiveHookName} requires an effect callback. ` + |
| 1353 | `Did you forget to pass a callback to the hook?`, |
| 1354 | }); |
| 1355 | return; |
| 1356 | } |
| 1357 | |
| 1358 | if (!maybeNode && isEffect && options.requireExplicitEffectDeps) { |
| 1359 | reportProblem({ |
| 1360 | node: reactiveHook, |
| 1361 | message: |
| 1362 | `React Hook ${reactiveHookName} always requires dependencies. ` + |
| 1363 | `Please add a dependency array or an explicit \`undefined\``, |
| 1364 | }); |
| 1365 | } |
| 1366 | |
| 1367 | const isAutoDepsHook = |
| 1368 | options.experimental_autoDependenciesHooks.includes(reactiveHookName); |
| 1369 | |
| 1370 | // Check the declared dependencies for this reactive hook. If there is no |
| 1371 | // second argument then the reactive callback will re-run on every render. |
| 1372 | // So no need to check for dependency inclusion. |
| 1373 | if ( |
| 1374 | (!declaredDependenciesNode || |
| 1375 | (isAutoDepsHook && |
| 1376 | declaredDependenciesNode.type === 'Literal' && |
| 1377 | declaredDependenciesNode.value === null)) && |
| 1378 | !isEffect |
| 1379 | ) { |
| 1380 | // These are only used for optimization. |
| 1381 | if ( |
| 1382 | reactiveHookName === 'useMemo' || |
| 1383 | reactiveHookName === 'useCallback' |
| 1384 | ) { |
| 1385 | // TODO: Can this have a suggestion? |
| 1386 | reportProblem({ |
| 1387 | node: reactiveHook, |
| 1388 | message: |
| 1389 | `React Hook ${reactiveHookName} does nothing when called with ` + |
| 1390 | `only one argument. Did you forget to pass an array of ` + |
| 1391 | `dependencies?`, |
| 1392 | }); |
| 1393 | } |
| 1394 | return; |
| 1395 | } |
| 1396 | |
| 1397 | while ( |
| 1398 | callback.type === 'TSAsExpression' || |
| 1399 | callback.type === 'AsExpression' |
| 1400 | ) { |
| 1401 | callback = callback.expression; |
| 1402 | } |
| 1403 | |
| 1404 | switch (callback.type) { |
| 1405 | case 'FunctionExpression': |
| 1406 | case 'ArrowFunctionExpression': |
| 1407 | visitFunctionWithDependencies( |
| 1408 | callback, |
| 1409 | declaredDependenciesNode, |
| 1410 | reactiveHook, |
| 1411 | reactiveHookName, |
| 1412 | isEffect, |
| 1413 | isAutoDepsHook, |
| 1414 | ); |
| 1415 | return; // Handled |
| 1416 | case 'Identifier': |
| 1417 | if ( |
| 1418 | !declaredDependenciesNode || |
| 1419 | (isAutoDepsHook && |
| 1420 | declaredDependenciesNode.type === 'Literal' && |
| 1421 | declaredDependenciesNode.value === null) |
| 1422 | ) { |
| 1423 | // Always runs, no problems. |
| 1424 | return; // Handled |
| 1425 | } |
| 1426 | // The function passed as a callback is not written inline. |
| 1427 | // But perhaps it's in the dependencies array? |
| 1428 | if ( |
| 1429 | 'elements' in declaredDependenciesNode && |
| 1430 | declaredDependenciesNode.elements && |
| 1431 | declaredDependenciesNode.elements.some( |
| 1432 | el => el && el.type === 'Identifier' && el.name === callback.name, |
| 1433 | ) |
| 1434 | ) { |
| 1435 | // If it's already in the list of deps, we don't care because |
| 1436 | // this is valid regardless. |
| 1437 | return; // Handled |
| 1438 | } |
| 1439 | // We'll do our best effort to find it, complain otherwise. |
| 1440 | const variable = getScope(callback).set.get(callback.name); |
| 1441 | if (variable == null || variable.defs == null) { |
| 1442 | // If it's not in scope, we don't care. |
| 1443 | return; // Handled |
| 1444 | } |
| 1445 | // The function passed as a callback is not written inline. |
| 1446 | // But it's defined somewhere in the render scope. |
| 1447 | // We'll do our best effort to find and check it, complain otherwise. |
| 1448 | const def = variable.defs[0]; |
| 1449 | if (!def || !def.node) { |
| 1450 | break; // Unhandled |
| 1451 | } |
| 1452 | if (def.type === 'Parameter') { |
| 1453 | reportProblem({ |
| 1454 | node: reactiveHook, |
| 1455 | message: getUnknownDependenciesMessage(reactiveHookName), |
| 1456 | }); |
| 1457 | return; |
| 1458 | } |
| 1459 | if (def.type !== 'Variable' && def.type !== 'FunctionName') { |
| 1460 | // Parameter or an unusual pattern. Bail out. |
| 1461 | break; // Unhandled |
| 1462 | } |
| 1463 | switch (def.node.type) { |
| 1464 | case 'FunctionDeclaration': |
| 1465 | // useEffect(() => { ... }, []); |
| 1466 | visitFunctionWithDependencies( |
| 1467 | def.node, |
| 1468 | declaredDependenciesNode, |
| 1469 | reactiveHook, |
| 1470 | reactiveHookName, |
| 1471 | isEffect, |
| 1472 | isAutoDepsHook, |
| 1473 | ); |
| 1474 | return; // Handled |
| 1475 | case 'VariableDeclarator': |
| 1476 | const init = def.node.init; |
| 1477 | if (!init) { |
| 1478 | break; // Unhandled |
| 1479 | } |
| 1480 | switch (init.type) { |
| 1481 | // const effectBody = () => {...}; |
| 1482 | // useEffect(effectBody, []); |
| 1483 | case 'ArrowFunctionExpression': |
| 1484 | case 'FunctionExpression': |
| 1485 | // We can inspect this function as if it were inline. |
| 1486 | visitFunctionWithDependencies( |
| 1487 | init, |
| 1488 | declaredDependenciesNode, |
| 1489 | reactiveHook, |
| 1490 | reactiveHookName, |
| 1491 | isEffect, |
| 1492 | isAutoDepsHook, |
| 1493 | ); |
| 1494 | return; // Handled |
| 1495 | } |
| 1496 | break; // Unhandled |
| 1497 | } |
| 1498 | break; // Unhandled |
| 1499 | default: |
| 1500 | // useEffect(generateEffectBody(), []); |
| 1501 | reportProblem({ |
| 1502 | node: reactiveHook, |
| 1503 | message: getUnknownDependenciesMessage(reactiveHookName), |
| 1504 | }); |
| 1505 | return; // Handled |
| 1506 | } |
| 1507 | |
| 1508 | // Something unusual. Fall back to suggesting to add the body itself as a dep. |
| 1509 | reportProblem({ |
| 1510 | node: reactiveHook, |
| 1511 | message: |
| 1512 | `React Hook ${reactiveHookName} has a missing dependency: '${callback.name}'. ` + |
| 1513 | `Either include it or remove the dependency array.`, |
| 1514 | suggest: [ |
| 1515 | { |
| 1516 | desc: `Update the dependencies array to be: [${callback.name}]`, |
| 1517 | fix(fixer) { |
| 1518 | return fixer.replaceText( |
| 1519 | declaredDependenciesNode, |
| 1520 | `[${callback.name}]`, |
| 1521 | ); |
| 1522 | }, |
| 1523 | }, |
| 1524 | ], |
| 1525 | }); |
| 1526 | } |
| 1527 | |
| 1528 | return { |
| 1529 | CallExpression: visitCallExpression, |
| 1530 | }; |
| 1531 | }, |
| 1532 | } satisfies Rule.RuleModule; |
| 1533 | |
| 1534 | // The meat of the logic. |
| 1535 | function collectRecommendations({ |
| 1536 | dependencies, |
| 1537 | declaredDependencies, |
| 1538 | stableDependencies, |
| 1539 | externalDependencies, |
| 1540 | isEffect, |
| 1541 | }: { |
| 1542 | dependencies: Map<string, Dependency>; |
| 1543 | declaredDependencies: Array<DeclaredDependency>; |
| 1544 | stableDependencies: Set<string>; |
| 1545 | externalDependencies: Set<string>; |
| 1546 | isEffect: boolean; |
| 1547 | }) { |
| 1548 | // Our primary data structure. |
| 1549 | // It is a logical representation of property chains: |
| 1550 | // `props` -> `props.foo` -> `props.foo.bar` -> `props.foo.bar.baz` |
| 1551 | // -> `props.lol` |
| 1552 | // -> `props.huh` -> `props.huh.okay` |
| 1553 | // -> `props.wow` |
| 1554 | // We'll use it to mark nodes that are *used* by the programmer, |
| 1555 | // and the nodes that were *declared* as deps. Then we will |
| 1556 | // traverse it to learn which deps are missing or unnecessary. |
| 1557 | const depTree = createDepTree(); |
| 1558 | function createDepTree(): DependencyTreeNode { |
| 1559 | return { |
| 1560 | isUsed: false, // True if used in code |
| 1561 | isSatisfiedRecursively: false, // True if specified in deps |
| 1562 | isSubtreeUsed: false, // True if something deeper is used by code |
| 1563 | children: new Map(), // Nodes for properties |
| 1564 | }; |
| 1565 | } |
| 1566 | |
| 1567 | // Mark all required nodes first. |
| 1568 | // Imagine exclamation marks next to each used deep property. |
| 1569 | dependencies.forEach((_, key) => { |
| 1570 | const node = getOrCreateNodeByPath(depTree, key); |
| 1571 | node.isUsed = true; |
| 1572 | markAllParentsByPath(depTree, key, parent => { |
| 1573 | parent.isSubtreeUsed = true; |
| 1574 | }); |
| 1575 | }); |
| 1576 | |
| 1577 | // Mark all satisfied nodes. |
| 1578 | // Imagine checkmarks next to each declared dependency. |
| 1579 | declaredDependencies.forEach(({key}) => { |
| 1580 | const node = getOrCreateNodeByPath(depTree, key); |
| 1581 | node.isSatisfiedRecursively = true; |
| 1582 | }); |
| 1583 | stableDependencies.forEach(key => { |
| 1584 | const node = getOrCreateNodeByPath(depTree, key); |
| 1585 | node.isSatisfiedRecursively = true; |
| 1586 | }); |
| 1587 | |
| 1588 | // Tree manipulation helpers. |
| 1589 | function getOrCreateNodeByPath( |
| 1590 | rootNode: DependencyTreeNode, |
| 1591 | path: string, |
| 1592 | ): DependencyTreeNode { |
| 1593 | const keys = path.split('.'); |
| 1594 | let node = rootNode; |
| 1595 | for (const key of keys) { |
| 1596 | let child = node.children.get(key); |
| 1597 | if (!child) { |
| 1598 | child = createDepTree(); |
| 1599 | node.children.set(key, child); |
| 1600 | } |
| 1601 | node = child; |
| 1602 | } |
| 1603 | return node; |
| 1604 | } |
| 1605 | function markAllParentsByPath( |
| 1606 | rootNode: DependencyTreeNode, |
| 1607 | path: string, |
| 1608 | fn: (node: DependencyTreeNode) => void, |
| 1609 | ): void { |
| 1610 | const keys = path.split('.'); |
| 1611 | let node = rootNode; |
| 1612 | for (const key of keys) { |
| 1613 | const child = node.children.get(key); |
| 1614 | if (!child) { |
| 1615 | return; |
| 1616 | } |
| 1617 | fn(child); |
| 1618 | node = child; |
| 1619 | } |
| 1620 | } |
| 1621 | |
| 1622 | // Now we can learn which dependencies are missing or necessary. |
| 1623 | const missingDependencies = new Set<string>(); |
| 1624 | const satisfyingDependencies = new Set<string>(); |
| 1625 | scanTreeRecursively( |
| 1626 | depTree, |
| 1627 | missingDependencies, |
| 1628 | satisfyingDependencies, |
| 1629 | key => key, |
| 1630 | ); |
| 1631 | function scanTreeRecursively( |
| 1632 | node: DependencyTreeNode, |
| 1633 | missingPaths: Set<string>, |
| 1634 | satisfyingPaths: Set<string>, |
| 1635 | keyToPath: (key: string) => string, |
| 1636 | ): void { |
| 1637 | node.children.forEach((child, key) => { |
| 1638 | const path = keyToPath(key); |
| 1639 | if (child.isSatisfiedRecursively) { |
| 1640 | if (child.isSubtreeUsed) { |
| 1641 | // Remember this dep actually satisfied something. |
| 1642 | satisfyingPaths.add(path); |
| 1643 | } |
| 1644 | // It doesn't matter if there's something deeper. |
| 1645 | // It would be transitively satisfied since we assume immutability. |
| 1646 | // `props.foo` is enough if you read `props.foo.id`. |
| 1647 | return; |
| 1648 | } |
| 1649 | if (child.isUsed) { |
| 1650 | // Remember that no declared deps satisfied this node. |
| 1651 | missingPaths.add(path); |
| 1652 | // If we got here, nothing in its subtree was satisfied. |
| 1653 | // No need to search further. |
| 1654 | return; |
| 1655 | } |
| 1656 | scanTreeRecursively( |
| 1657 | child, |
| 1658 | missingPaths, |
| 1659 | satisfyingPaths, |
| 1660 | childKey => path + '.' + childKey, |
| 1661 | ); |
| 1662 | }); |
| 1663 | } |
| 1664 | |
| 1665 | // Collect suggestions in the order they were originally specified. |
| 1666 | const suggestedDependencies: Array<string> = []; |
| 1667 | const unnecessaryDependencies = new Set<string>(); |
| 1668 | const duplicateDependencies = new Set<string>(); |
| 1669 | declaredDependencies.forEach(({key}) => { |
| 1670 | // Does this declared dep satisfy a real need? |
| 1671 | if (satisfyingDependencies.has(key)) { |
| 1672 | if (suggestedDependencies.indexOf(key) === -1) { |
| 1673 | // Good one. |
| 1674 | suggestedDependencies.push(key); |
| 1675 | } else { |
| 1676 | // Duplicate. |
| 1677 | duplicateDependencies.add(key); |
| 1678 | } |
| 1679 | } else { |
| 1680 | if ( |
| 1681 | isEffect && |
| 1682 | !key.endsWith('.current') && |
| 1683 | !externalDependencies.has(key) |
| 1684 | ) { |
| 1685 | // Effects are allowed extra "unnecessary" deps. |
| 1686 | // Such as resetting scroll when ID changes. |
| 1687 | // Consider them legit. |
| 1688 | // The exception is ref.current which is always wrong. |
| 1689 | if (suggestedDependencies.indexOf(key) === -1) { |
| 1690 | suggestedDependencies.push(key); |
| 1691 | } |
| 1692 | } else { |
| 1693 | // It's definitely not needed. |
| 1694 | unnecessaryDependencies.add(key); |
| 1695 | } |
| 1696 | } |
| 1697 | }); |
| 1698 | |
| 1699 | // Then add the missing ones at the end. |
| 1700 | missingDependencies.forEach(key => { |
| 1701 | suggestedDependencies.push(key); |
| 1702 | }); |
| 1703 | |
| 1704 | return { |
| 1705 | suggestedDependencies, |
| 1706 | unnecessaryDependencies, |
| 1707 | duplicateDependencies, |
| 1708 | missingDependencies, |
| 1709 | }; |
| 1710 | } |
| 1711 | |
| 1712 | // If the node will result in constructing a referentially unique value, return |
| 1713 | // its human readable type name, else return null. |
| 1714 | function getConstructionExpressionType(node: Node): string | null { |
| 1715 | switch (node.type) { |
| 1716 | case 'ObjectExpression': |
| 1717 | return 'object'; |
| 1718 | case 'ArrayExpression': |
| 1719 | return 'array'; |
| 1720 | case 'ArrowFunctionExpression': |
| 1721 | case 'FunctionExpression': |
| 1722 | return 'function'; |
| 1723 | case 'ClassExpression': |
| 1724 | return 'class'; |
| 1725 | case 'ConditionalExpression': |
| 1726 | if ( |
| 1727 | getConstructionExpressionType(node.consequent) != null || |
| 1728 | getConstructionExpressionType(node.alternate) != null |
| 1729 | ) { |
| 1730 | return 'conditional'; |
| 1731 | } |
| 1732 | return null; |
| 1733 | case 'LogicalExpression': |
| 1734 | if ( |
| 1735 | getConstructionExpressionType(node.left) != null || |
| 1736 | getConstructionExpressionType(node.right) != null |
| 1737 | ) { |
| 1738 | return 'logical expression'; |
| 1739 | } |
| 1740 | return null; |
| 1741 | case 'JSXFragment': |
| 1742 | return 'JSX fragment'; |
| 1743 | case 'JSXElement': |
| 1744 | return 'JSX element'; |
| 1745 | case 'AssignmentExpression': |
| 1746 | if (getConstructionExpressionType(node.right) != null) { |
| 1747 | return 'assignment expression'; |
| 1748 | } |
| 1749 | return null; |
| 1750 | case 'NewExpression': |
| 1751 | return 'object construction'; |
| 1752 | case 'Literal': |
| 1753 | if (node.value instanceof RegExp) { |
| 1754 | return 'regular expression'; |
| 1755 | } |
| 1756 | return null; |
| 1757 | case 'TypeCastExpression': |
| 1758 | case 'AsExpression': |
| 1759 | case 'TSAsExpression': |
| 1760 | return getConstructionExpressionType(node.expression); |
| 1761 | } |
| 1762 | return null; |
| 1763 | } |
| 1764 | |
| 1765 | // Finds variables declared as dependencies |
| 1766 | // that would invalidate on every render. |
| 1767 | function scanForConstructions({ |
| 1768 | declaredDependencies, |
| 1769 | declaredDependenciesNode, |
| 1770 | componentScope, |
| 1771 | scope, |
| 1772 | }: { |
| 1773 | declaredDependencies: Array<DeclaredDependency>; |
| 1774 | declaredDependenciesNode: Node; |
| 1775 | componentScope: Scope.Scope; |
| 1776 | scope: Scope.Scope; |
| 1777 | }) { |
| 1778 | const constructions = declaredDependencies |
| 1779 | .map(({key}) => { |
| 1780 | const ref = componentScope.variables.find(v => v.name === key); |
| 1781 | if (ref == null) { |
| 1782 | return null; |
| 1783 | } |
| 1784 | |
| 1785 | const node = ref.defs[0]; |
| 1786 | if (node == null) { |
| 1787 | return null; |
| 1788 | } |
| 1789 | // const handleChange = function () {} |
| 1790 | // const handleChange = () => {} |
| 1791 | // const foo = {} |
| 1792 | // const foo = [] |
| 1793 | // etc. |
| 1794 | if ( |
| 1795 | node.type === 'Variable' && |
| 1796 | node.node.type === 'VariableDeclarator' && |
| 1797 | node.node.id.type === 'Identifier' && // Ensure this is not destructed assignment |
| 1798 | node.node.init != null |
| 1799 | ) { |
| 1800 | const constantExpressionType = getConstructionExpressionType( |
| 1801 | node.node.init, |
| 1802 | ); |
| 1803 | if (constantExpressionType) { |
| 1804 | return [ref, constantExpressionType]; |
| 1805 | } |
| 1806 | } |
| 1807 | // function handleChange() {} |
| 1808 | if ( |
| 1809 | node.type === 'FunctionName' && |
| 1810 | node.node.type === 'FunctionDeclaration' |
| 1811 | ) { |
| 1812 | return [ref, 'function']; |
| 1813 | } |
| 1814 | |
| 1815 | // class Foo {} |
| 1816 | if (node.type === 'ClassName' && node.node.type === 'ClassDeclaration') { |
| 1817 | return [ref, 'class']; |
| 1818 | } |
| 1819 | return null; |
| 1820 | }) |
| 1821 | .filter(Boolean) as Array<[Scope.Variable, string]>; |
| 1822 | |
| 1823 | function isUsedOutsideOfHook(ref: Scope.Variable): boolean { |
| 1824 | let foundWriteExpr = false; |
| 1825 | for (const reference of ref.references) { |
| 1826 | if (reference.writeExpr) { |
| 1827 | if (foundWriteExpr) { |
| 1828 | // Two writes to the same function. |
| 1829 | return true; |
| 1830 | } else { |
| 1831 | // Ignore first write as it's not usage. |
| 1832 | foundWriteExpr = true; |
| 1833 | continue; |
| 1834 | } |
| 1835 | } |
| 1836 | let currentScope: Scope.Scope | null = reference.from; |
| 1837 | while (currentScope !== scope && currentScope != null) { |
| 1838 | currentScope = currentScope.upper; |
| 1839 | } |
| 1840 | if (currentScope !== scope) { |
| 1841 | // This reference is outside the Hook callback. |
| 1842 | // It can only be legit if it's the deps array. |
| 1843 | if (!isAncestorNodeOf(declaredDependenciesNode, reference.identifier)) { |
| 1844 | return true; |
| 1845 | } |
| 1846 | } |
| 1847 | } |
| 1848 | return false; |
| 1849 | } |
| 1850 | |
| 1851 | return constructions.map(([ref, depType]) => ({ |
| 1852 | construction: ref.defs[0] as Scope.Definition, |
| 1853 | depType, |
| 1854 | isUsedOutsideOfHook: isUsedOutsideOfHook(ref), |
| 1855 | })); |
| 1856 | } |
| 1857 | |
| 1858 | /** |
| 1859 | * Assuming () means the passed/returned node: |
| 1860 | * (props) => (props) |
| 1861 | * props.(foo) => (props.foo) |
| 1862 | * props.foo.(bar) => (props).foo.bar |
| 1863 | * props.foo.bar.(baz) => (props).foo.bar.baz |
| 1864 | */ |
| 1865 | function getDependency(node: Node): Node { |
| 1866 | if ( |
| 1867 | node.parent && |
| 1868 | (node.parent.type === 'MemberExpression' || |
| 1869 | node.parent.type === 'OptionalMemberExpression') && |
| 1870 | node.parent.object === node && |
| 1871 | 'name' in node.parent.property && |
| 1872 | node.parent.property.name !== 'current' && |
| 1873 | !node.parent.computed && |
| 1874 | !( |
| 1875 | node.parent.parent != null && |
| 1876 | (node.parent.parent.type === 'CallExpression' || |
| 1877 | node.parent.parent.type === 'OptionalCallExpression') && |
| 1878 | node.parent.parent.callee === node.parent |
| 1879 | ) |
| 1880 | ) { |
| 1881 | return getDependency(node.parent); |
| 1882 | } else if ( |
| 1883 | // Note: we don't check OptionalMemberExpression because it can't be LHS. |
| 1884 | node.type === 'MemberExpression' && |
| 1885 | node.parent && |
| 1886 | node.parent.type === 'AssignmentExpression' && |
| 1887 | node.parent.left === node |
| 1888 | ) { |
| 1889 | return node.object; |
| 1890 | } else { |
| 1891 | return node; |
| 1892 | } |
| 1893 | } |
| 1894 | |
| 1895 | /** |
| 1896 | * Mark a node as either optional or required. |
| 1897 | * Note: If the node argument is an OptionalMemberExpression, it doesn't necessarily mean it is optional. |
| 1898 | * It just means there is an optional member somewhere inside. |
| 1899 | * This particular node might still represent a required member, so check .optional field. |
| 1900 | */ |
| 1901 | function markNode( |
| 1902 | node: Node, |
| 1903 | optionalChains: Map<string, boolean> | null, |
| 1904 | result: string, |
| 1905 | ): void { |
| 1906 | if (optionalChains) { |
| 1907 | if ('optional' in node && node.optional) { |
| 1908 | // We only want to consider it optional if *all* usages were optional. |
| 1909 | if (!optionalChains.has(result)) { |
| 1910 | // Mark as (maybe) optional. If there's a required usage, this will be overridden. |
| 1911 | optionalChains.set(result, true); |
| 1912 | } |
| 1913 | } else { |
| 1914 | // Mark as required. |
| 1915 | optionalChains.set(result, false); |
| 1916 | } |
| 1917 | } |
| 1918 | } |
| 1919 | |
| 1920 | /** |
| 1921 | * Assuming () means the passed node. |
| 1922 | * (foo) -> 'foo' |
| 1923 | * foo(.)bar -> 'foo.bar' |
| 1924 | * foo.bar(.)baz -> 'foo.bar.baz' |
| 1925 | * Otherwise throw. |
| 1926 | */ |
| 1927 | function analyzePropertyChain( |
| 1928 | node: Node, |
| 1929 | optionalChains: Map<string, boolean> | null, |
| 1930 | ): string { |
| 1931 | if (node.type === 'Identifier' || node.type === 'JSXIdentifier') { |
| 1932 | const result = node.name; |
| 1933 | if (optionalChains) { |
| 1934 | // Mark as required. |
| 1935 | optionalChains.set(result, false); |
| 1936 | } |
| 1937 | return result; |
| 1938 | } else if (node.type === 'MemberExpression' && !node.computed) { |
| 1939 | const object = analyzePropertyChain(node.object, optionalChains); |
| 1940 | const property = analyzePropertyChain(node.property, null); |
| 1941 | const result = `${object}.${property}`; |
| 1942 | markNode(node, optionalChains, result); |
| 1943 | return result; |
| 1944 | } else if (node.type === 'OptionalMemberExpression' && !node.computed) { |
| 1945 | const object = analyzePropertyChain(node.object, optionalChains); |
| 1946 | const property = analyzePropertyChain(node.property, null); |
| 1947 | const result = `${object}.${property}`; |
| 1948 | markNode(node, optionalChains, result); |
| 1949 | return result; |
| 1950 | } else if ( |
| 1951 | node.type === 'ChainExpression' && |
| 1952 | (!('computed' in node) || !node.computed) |
| 1953 | ) { |
| 1954 | const expression = node.expression; |
| 1955 | |
| 1956 | if (expression.type === 'CallExpression') { |
| 1957 | throw new Error(`Unsupported node type: ${expression.type}`); |
| 1958 | } |
| 1959 | |
| 1960 | const object = analyzePropertyChain(expression.object, optionalChains); |
| 1961 | const property = analyzePropertyChain(expression.property, null); |
| 1962 | const result = `${object}.${property}`; |
| 1963 | markNode(expression, optionalChains, result); |
| 1964 | return result; |
| 1965 | } else { |
| 1966 | throw new Error(`Unsupported node type: ${node.type}`); |
| 1967 | } |
| 1968 | } |
| 1969 | |
| 1970 | function getNodeWithoutReactNamespace( |
| 1971 | node: Expression | Super, |
| 1972 | ): Expression | Identifier | Super { |
| 1973 | if ( |
| 1974 | node.type === 'MemberExpression' && |
| 1975 | node.object.type === 'Identifier' && |
| 1976 | node.object.name === 'React' && |
| 1977 | node.property.type === 'Identifier' && |
| 1978 | !node.computed |
| 1979 | ) { |
| 1980 | return node.property; |
| 1981 | } |
| 1982 | return node; |
| 1983 | } |
| 1984 | |
| 1985 | // What's the index of callback that needs to be analyzed for a given Hook? |
| 1986 | // -1 if it's not a Hook we care about (e.g. useState). |
| 1987 | // 0 for useEffect/useMemo/useCallback(fn). |
| 1988 | // 1 for useImperativeHandle(ref, fn). |
| 1989 | // For additionally configured Hooks, assume that they're like useEffect (0). |
| 1990 | function getReactiveHookCallbackIndex( |
| 1991 | calleeNode: Expression | Super, |
| 1992 | options?: { |
| 1993 | additionalHooks: RegExp | undefined; |
| 1994 | enableDangerousAutofixThisMayCauseInfiniteLoops?: boolean; |
| 1995 | }, |
| 1996 | ): 0 | -1 | 1 { |
| 1997 | const node = getNodeWithoutReactNamespace(calleeNode); |
| 1998 | if (node.type !== 'Identifier') { |
| 1999 | return -1; |
| 2000 | } |
| 2001 | switch (node.name) { |
| 2002 | case 'useEffect': |
| 2003 | case 'useLayoutEffect': |
| 2004 | case 'useCallback': |
| 2005 | case 'useMemo': |
| 2006 | // useEffect(fn) |
| 2007 | return 0; |
| 2008 | case 'useImperativeHandle': |
| 2009 | // useImperativeHandle(ref, fn) |
| 2010 | return 1; |
| 2011 | default: |
| 2012 | if (node === calleeNode && options && options.additionalHooks) { |
| 2013 | // Allow the user to provide a regular expression which enables the lint to |
| 2014 | // target custom reactive hooks. |
| 2015 | let name; |
| 2016 | try { |
| 2017 | name = analyzePropertyChain(node, null); |
| 2018 | } catch (error: unknown) { |
| 2019 | if ( |
| 2020 | error instanceof Error && |
| 2021 | /Unsupported node type/.test(error.message) |
| 2022 | ) { |
| 2023 | return 0; |
| 2024 | } else { |
| 2025 | throw error; |
| 2026 | } |
| 2027 | } |
| 2028 | return options.additionalHooks.test(name) ? 0 : -1; |
| 2029 | } else { |
| 2030 | return -1; |
| 2031 | } |
| 2032 | } |
| 2033 | } |
| 2034 | |
| 2035 | /** |
| 2036 | * ESLint won't assign node.parent to references from context.getScope() |
| 2037 | * |
| 2038 | * So instead we search for the node from an ancestor assigning node.parent |
| 2039 | * as we go. This mutates the AST. |
| 2040 | * |
| 2041 | * This traversal is: |
| 2042 | * - optimized by only searching nodes with a range surrounding our target node |
| 2043 | * - agnostic to AST node types, it looks for `{ type: string, ... }` |
| 2044 | */ |
| 2045 | function fastFindReferenceWithParent(start: Node, target: Node): Node | null { |
| 2046 | const queue = [start]; |
| 2047 | let item: Node; |
| 2048 | |
| 2049 | while (queue.length) { |
| 2050 | item = queue.shift() as Node; |
| 2051 | |
| 2052 | if (isSameIdentifier(item, target)) { |
| 2053 | return item; |
| 2054 | } |
| 2055 | |
| 2056 | if (!isAncestorNodeOf(item, target)) { |
| 2057 | continue; |
| 2058 | } |
| 2059 | |
| 2060 | for (const [key, value] of Object.entries(item)) { |
| 2061 | if (key === 'parent') { |
| 2062 | continue; |
| 2063 | } |
| 2064 | if (isNodeLike(value)) { |
| 2065 | value.parent = item; |
| 2066 | queue.push(value); |
| 2067 | } else if (Array.isArray(value)) { |
| 2068 | value.forEach(val => { |
| 2069 | if (isNodeLike(val)) { |
| 2070 | val.parent = item; |
| 2071 | queue.push(val); |
| 2072 | } |
| 2073 | }); |
| 2074 | } |
| 2075 | } |
| 2076 | } |
| 2077 | |
| 2078 | return null; |
| 2079 | } |
| 2080 | |
| 2081 | function joinEnglish(arr: Array<string>): string { |
| 2082 | let s = ''; |
| 2083 | for (let i = 0; i < arr.length; i++) { |
| 2084 | s += arr[i]; |
| 2085 | if (i === 0 && arr.length === 2) { |
| 2086 | s += ' and '; |
| 2087 | } else if (i === arr.length - 2 && arr.length > 2) { |
| 2088 | s += ', and '; |
| 2089 | } else if (i < arr.length - 1) { |
| 2090 | s += ', '; |
| 2091 | } |
| 2092 | } |
| 2093 | return s; |
| 2094 | } |
| 2095 | |
| 2096 | function isNodeLike(val: unknown): boolean { |
| 2097 | return ( |
| 2098 | typeof val === 'object' && |
| 2099 | val !== null && |
| 2100 | !Array.isArray(val) && |
| 2101 | 'type' in val && |
| 2102 | typeof val.type === 'string' |
| 2103 | ); |
| 2104 | } |
| 2105 | |
| 2106 | function isSameIdentifier(a: Node, b: Node): boolean { |
| 2107 | return ( |
| 2108 | (a.type === 'Identifier' || a.type === 'JSXIdentifier') && |
| 2109 | a.type === b.type && |
| 2110 | a.name === b.name && |
| 2111 | !!a.range && |
| 2112 | !!b.range && |
| 2113 | a.range[0] === b.range[0] && |
| 2114 | a.range[1] === b.range[1] |
| 2115 | ); |
| 2116 | } |
| 2117 | |
| 2118 | function isAncestorNodeOf(a: Node, b: Node): boolean { |
| 2119 | return ( |
| 2120 | !!a.range && |
| 2121 | !!b.range && |
| 2122 | a.range[0] <= b.range[0] && |
| 2123 | a.range[1] >= b.range[1] |
| 2124 | ); |
| 2125 | } |
| 2126 | |
| 2127 | function isUseEffectEventIdentifier(node: Node): boolean { |
| 2128 | return node.type === 'Identifier' && node.name === 'useEffectEvent'; |
| 2129 | } |
| 2130 | |
| 2131 | function getUnknownDependenciesMessage(reactiveHookName: string): string { |
| 2132 | return ( |
| 2133 | `React Hook ${reactiveHookName} received a function whose dependencies ` + |
| 2134 | `are unknown. Pass an inline function instead.` |
| 2135 | ); |
| 2136 | } |
| 2137 | |
| 2138 | export default rule; |