| 1 | 'use strict'; |
| 2 | |
| 3 | /* eslint-disable no-for-of-loops/no-for-of-loops */ |
| 4 | |
| 5 | const getComments = require('./getComments'); |
| 6 | |
| 7 | function transform(babel) { |
| 8 | const {types: t} = babel; |
| 9 | |
| 10 | // A very stupid subset of pseudo-JavaScript, used to run tests conditionally |
| 11 | // based on the environment. |
| 12 | // |
| 13 | // Input: |
| 14 | // @gate a && (b || c) |
| 15 | // test('some test', () => {/*...*/}) |
| 16 | // |
| 17 | // Output: |
| 18 | // @gate a && (b || c) |
| 19 | // _test_gate(ctx => ctx.a && (ctx.b || ctx.c), 'some test', () => {/*...*/}); |
| 20 | // |
| 21 | // expression → binary ( ( "||" | "&&" ) binary)* ; |
| 22 | // binary → unary ( ( "==" | "!=" | "===" | "!==" ) unary )* ; |
| 23 | // unary → "!" primary |
| 24 | // | primary ; |
| 25 | // primary → NAME | STRING | BOOLEAN |
| 26 | // | "(" expression ")" ; |
| 27 | function tokenize(code) { |
| 28 | const tokens = []; |
| 29 | let i = 0; |
| 30 | while (i < code.length) { |
| 31 | let char = code[i]; |
| 32 | // Double quoted strings |
| 33 | if (char === '"') { |
| 34 | let string = ''; |
| 35 | i++; |
| 36 | do { |
| 37 | if (i > code.length) { |
| 38 | throw Error('Missing a closing quote'); |
| 39 | } |
| 40 | char = code[i++]; |
| 41 | if (char === '"') { |
| 42 | break; |
| 43 | } |
| 44 | string += char; |
| 45 | } while (true); |
| 46 | tokens.push({type: 'string', value: string}); |
| 47 | continue; |
| 48 | } |
| 49 | |
| 50 | // Single quoted strings |
| 51 | if (char === "'") { |
| 52 | let string = ''; |
| 53 | i++; |
| 54 | do { |
| 55 | if (i > code.length) { |
| 56 | throw Error('Missing a closing quote'); |
| 57 | } |
| 58 | char = code[i++]; |
| 59 | if (char === "'") { |
| 60 | break; |
| 61 | } |
| 62 | string += char; |
| 63 | } while (true); |
| 64 | tokens.push({type: 'string', value: string}); |
| 65 | continue; |
| 66 | } |
| 67 | |
| 68 | // Whitespace |
| 69 | if (/\s/.test(char)) { |
| 70 | if (char === '\n') { |
| 71 | return tokens; |
| 72 | } |
| 73 | i++; |
| 74 | continue; |
| 75 | } |
| 76 | |
| 77 | const next3 = code.slice(i, i + 3); |
| 78 | if (next3 === '===') { |
| 79 | tokens.push({type: '=='}); |
| 80 | i += 3; |
| 81 | continue; |
| 82 | } |
| 83 | if (next3 === '!==') { |
| 84 | tokens.push({type: '!='}); |
| 85 | i += 3; |
| 86 | continue; |
| 87 | } |
| 88 | |
| 89 | const next2 = code.slice(i, i + 2); |
| 90 | switch (next2) { |
| 91 | case '&&': |
| 92 | case '||': |
| 93 | case '==': |
| 94 | case '!=': |
| 95 | tokens.push({type: next2}); |
| 96 | i += 2; |
| 97 | continue; |
| 98 | case '//': |
| 99 | // This is the beginning of a line comment. The rest of the line |
| 100 | // is ignored. |
| 101 | return tokens; |
| 102 | } |
| 103 | |
| 104 | switch (char) { |
| 105 | case '(': |
| 106 | case ')': |
| 107 | case '!': |
| 108 | tokens.push({type: char}); |
| 109 | i++; |
| 110 | continue; |
| 111 | } |
| 112 | |
| 113 | // Names |
| 114 | const nameRegex = /[a-zA-Z_$][0-9a-zA-Z_$]*/y; |
| 115 | nameRegex.lastIndex = i; |
| 116 | const match = nameRegex.exec(code); |
| 117 | if (match !== null) { |
| 118 | const name = match[0]; |
| 119 | switch (name) { |
| 120 | case 'true': { |
| 121 | tokens.push({type: 'boolean', value: true}); |
| 122 | break; |
| 123 | } |
| 124 | case 'false': { |
| 125 | tokens.push({type: 'boolean', value: false}); |
| 126 | break; |
| 127 | } |
| 128 | default: { |
| 129 | tokens.push({type: 'name', name}); |
| 130 | } |
| 131 | } |
| 132 | i += name.length; |
| 133 | continue; |
| 134 | } |
| 135 | |
| 136 | throw Error('Invalid character: ' + char); |
| 137 | } |
| 138 | return tokens; |
| 139 | } |
| 140 | |
| 141 | function parse(code, ctxIdentifier) { |
| 142 | const tokens = tokenize(code); |
| 143 | |
| 144 | let i = 0; |
| 145 | function parseExpression() { |
| 146 | let left = parseBinary(); |
| 147 | while (true) { |
| 148 | const token = tokens[i]; |
| 149 | if (token !== undefined) { |
| 150 | switch (token.type) { |
| 151 | case '||': |
| 152 | case '&&': { |
| 153 | i++; |
| 154 | const right = parseBinary(); |
| 155 | if (right === null) { |
| 156 | throw Error('Missing expression after ' + token.type); |
| 157 | } |
| 158 | left = t.logicalExpression(token.type, left, right); |
| 159 | continue; |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | break; |
| 164 | } |
| 165 | return left; |
| 166 | } |
| 167 | |
| 168 | function parseBinary() { |
| 169 | let left = parseUnary(); |
| 170 | while (true) { |
| 171 | const token = tokens[i]; |
| 172 | if (token !== undefined) { |
| 173 | switch (token.type) { |
| 174 | case '==': |
| 175 | case '!=': { |
| 176 | i++; |
| 177 | const right = parseUnary(); |
| 178 | if (right === null) { |
| 179 | throw Error('Missing expression after ' + token.type); |
| 180 | } |
| 181 | left = t.binaryExpression(token.type, left, right); |
| 182 | continue; |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | break; |
| 187 | } |
| 188 | return left; |
| 189 | } |
| 190 | |
| 191 | function parseUnary() { |
| 192 | const token = tokens[i]; |
| 193 | if (token !== undefined) { |
| 194 | if (token.type === '!') { |
| 195 | i++; |
| 196 | const argument = parseUnary(); |
| 197 | return t.unaryExpression('!', argument); |
| 198 | } |
| 199 | } |
| 200 | return parsePrimary(); |
| 201 | } |
| 202 | |
| 203 | function parsePrimary() { |
| 204 | const token = tokens[i]; |
| 205 | switch (token.type) { |
| 206 | case 'boolean': { |
| 207 | i++; |
| 208 | return t.booleanLiteral(token.value); |
| 209 | } |
| 210 | case 'name': { |
| 211 | i++; |
| 212 | return t.memberExpression(ctxIdentifier, t.identifier(token.name)); |
| 213 | } |
| 214 | case 'string': { |
| 215 | i++; |
| 216 | return t.stringLiteral(token.value); |
| 217 | } |
| 218 | case '(': { |
| 219 | i++; |
| 220 | const expression = parseExpression(); |
| 221 | const closingParen = tokens[i]; |
| 222 | if (closingParen === undefined || closingParen.type !== ')') { |
| 223 | throw Error('Expected closing )'); |
| 224 | } |
| 225 | i++; |
| 226 | return expression; |
| 227 | } |
| 228 | default: { |
| 229 | throw Error('Unexpected token: ' + token.type); |
| 230 | } |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | const program = parseExpression(); |
| 235 | if (tokens[i] !== undefined) { |
| 236 | throw Error('Unexpected token'); |
| 237 | } |
| 238 | return program; |
| 239 | } |
| 240 | |
| 241 | function buildGateCondition(comments) { |
| 242 | let conditions = null; |
| 243 | for (const line of comments) { |
| 244 | const commentStr = line.value.trim(); |
| 245 | if (commentStr.startsWith('@gate ')) { |
| 246 | const code = commentStr.slice(6); |
| 247 | const ctxIdentifier = t.identifier('ctx'); |
| 248 | const condition = parse(code, ctxIdentifier); |
| 249 | if (conditions === null) { |
| 250 | conditions = [condition]; |
| 251 | } else { |
| 252 | conditions.push(condition); |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | if (conditions !== null) { |
| 257 | let condition = conditions[0]; |
| 258 | for (let i = 1; i < conditions.length; i++) { |
| 259 | const right = conditions[i]; |
| 260 | condition = t.logicalExpression('&&', condition, right); |
| 261 | } |
| 262 | return condition; |
| 263 | } else { |
| 264 | return null; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | return { |
| 269 | name: 'test-gate-pragma', |
| 270 | visitor: { |
| 271 | ExpressionStatement(path) { |
| 272 | const statement = path.node; |
| 273 | const expression = statement.expression; |
| 274 | if (expression.type === 'CallExpression') { |
| 275 | const callee = expression.callee; |
| 276 | switch (callee.type) { |
| 277 | case 'Identifier': { |
| 278 | if ( |
| 279 | callee.name === 'test' || |
| 280 | callee.name === 'it' || |
| 281 | callee.name === 'fit' |
| 282 | ) { |
| 283 | const comments = getComments(path); |
| 284 | if (comments !== undefined) { |
| 285 | const condition = buildGateCondition(comments); |
| 286 | if (condition !== null) { |
| 287 | callee.name = |
| 288 | callee.name === 'fit' ? '_test_gate_focus' : '_test_gate'; |
| 289 | expression.arguments = [ |
| 290 | t.arrowFunctionExpression( |
| 291 | [t.identifier('ctx')], |
| 292 | condition |
| 293 | ), |
| 294 | ...expression.arguments, |
| 295 | ]; |
| 296 | } |
| 297 | } |
| 298 | } |
| 299 | break; |
| 300 | } |
| 301 | case 'MemberExpression': { |
| 302 | if ( |
| 303 | callee.object.type === 'Identifier' && |
| 304 | (callee.object.name === 'test' || |
| 305 | callee.object.name === 'it') && |
| 306 | callee.property.type === 'Identifier' && |
| 307 | callee.property.name === 'only' |
| 308 | ) { |
| 309 | const comments = getComments(path); |
| 310 | if (comments !== undefined) { |
| 311 | const condition = buildGateCondition(comments); |
| 312 | if (condition !== null) { |
| 313 | statement.expression = t.callExpression( |
| 314 | t.identifier('_test_gate_focus'), |
| 315 | [ |
| 316 | t.arrowFunctionExpression( |
| 317 | [t.identifier('ctx')], |
| 318 | condition |
| 319 | ), |
| 320 | ...expression.arguments, |
| 321 | ] |
| 322 | ); |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | break; |
| 327 | } |
| 328 | } |
| 329 | } |
| 330 | return; |
| 331 | }, |
| 332 | }, |
| 333 | }; |
| 334 | } |
| 335 | |
| 336 | module.exports = transform; |