PropagateScopeDeps treats switch w only default as unconditional
If we have a switch with only a default case, then that code will be executed unconditionally. PropagateScopeDeps can take advantage of this to record dependencies in these cases as unconditional, which avoids the issue seen in the previous PR.
Joe Savona committed
Mar 22, 2024 at 09:02 UTC
7dc08d79be1bd7938757d03bd58fc662f647bbd7
5 files changed
+85
-27
compiler/packages/babel-plugin-react-forget/src/ReactiveScopes/PropagateScopeDependencies.ts
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@@ -732,6 +732,15 @@ class PropagationVisitor extends ReactiveFunctionVisitor<Context> {
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}
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case "switch": {
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context.visitOperand(terminal.test);
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+ const isDefaultOnly =
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+ terminal.cases.length === 1 && terminal.cases[0].test == null;
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+ if (isDefaultOnly) {
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+ const case_ = terminal.cases[0];
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+ if (case_.block != null) {
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+ this.visitBlock(case_.block, context);
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+ break;
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+ }
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+ }
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const depsInCases = [];
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let foundDefault = false;
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/*
compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-switch-with-only-default.expect.md
deleted
-21
@@ -1,21 +0,0 @@
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-
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-## Input
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-
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-```javascript
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-function Component({ kind, ...props }) {
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- switch (kind) {
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- default:
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- return <Stringify {...props} />;
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- }
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-}
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-
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-```
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-
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-
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-## Error
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-
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-```
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-[ReactForget] Invariant: Expected trees to be at least 2 elements long.
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-```
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-
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-
\ No newline at end of file
compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-switch-with-only-default.js
deleted
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@@ -1,6 +0,0 @@
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-function Component({ kind, ...props }) {
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- switch (kind) {
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- default:
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- return <Stringify {...props} />;
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- }
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-}
compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/switch-with-only-default.expect.md
new
+63
@@ -0,0 +1,63 @@
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+
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+## Input
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+
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+```javascript
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+import { Stringify } from "shared-runtime";
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+
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+function Component({ kind, ...props }) {
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+ switch (kind) {
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+ default:
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+ return <Stringify {...props} />;
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+ }
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+}
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+
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+export const FIXTURE_ENTRYPOINT = {
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+ fn: Component,
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+ params: [{ kind: "foo", a: 1, b: true, c: "sathya" }],
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+};
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+
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+```
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+
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+## Code
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+
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+```javascript
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+import { unstable_useMemoCache as useMemoCache } from "react";
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+import { Stringify } from "shared-runtime";
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+
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+function Component(t0) {
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+ const $ = useMemoCache(5);
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+ let kind;
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+ let props;
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+ if ($[0] !== t0) {
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+ ({ kind, ...props } = t0);
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+ $[0] = t0;
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+ $[1] = kind;
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+ $[2] = props;
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+ } else {
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+ kind = $[1];
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+ props = $[2];
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+ }
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+ switch (kind) {
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+ default: {
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+ let t1;
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+ if ($[3] !== props) {
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+ t1 = <Stringify {...props} />;
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+ $[3] = props;
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+ $[4] = t1;
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+ } else {
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+ t1 = $[4];
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+ }
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+ return t1;
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+ }
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+ }
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+}
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+
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+export const FIXTURE_ENTRYPOINT = {
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+ fn: Component,
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+ params: [{ kind: "foo", a: 1, b: true, c: "sathya" }],
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+};
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+
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+```
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+
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+### Eval output
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+(kind: ok) <div>{"a":1,"b":true,"c":"sathya"}</div>
\ No newline at end of file
compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/switch-with-only-default.js
new
+13
@@ -0,0 +1,13 @@
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+import { Stringify } from "shared-runtime";
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+
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+function Component({ kind, ...props }) {
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+ switch (kind) {
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+ default:
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+ return <Stringify {...props} />;
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+ }
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+}
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+
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+export const FIXTURE_ENTRYPOINT = {
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+ fn: Component,
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+ params: [{ kind: "foo", a: 1, b: true, c: "sathya" }],
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+};