[λ] Support member expressions in lambdas
Lower member expression if the receiver is in scope. Skip the remaining path before capturing so we don't recurse down the identifiers in the member expression.
Sathya Gunasekaran committed
Jan 19, 2023 at 12:13 UTC
f42c51b9718aa767eb3d863f866938d0a13ad74e
9 files changed
+281
-3
compiler/forget/src/HIR/BuildHIR.ts
+8
-3
@@ -1665,16 +1665,21 @@ function gatherCapturedDeps(
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fn.get("body").traverse({
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Expression(path) {
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- // TODO(gsn): Handle member expressions
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- if (!path.isIdentifier()) {
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+ let obj = path;
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+ while (obj.isMemberExpression()) {
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+ obj = obj.get("object");
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+ }
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+
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+ if (!obj.isIdentifier()) {
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return;
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}
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- const binding = path.scope.getBinding(path.node.name);
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+ const binding = obj.scope.getBinding(obj.node.name);
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if (binding === undefined || !pureScopes.has(binding.scope)) {
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return;
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}
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+ path.skip();
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captured.add(lowerExpressionToPlace(builder, path));
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},
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});
compiler/forget/src/__tests__/fixtures/hir/capturing-member-expr.expect.md
new
+50
@@ -0,0 +1,50 @@
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+
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+## Input
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+
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+```javascript
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+function component(a) {
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+ let z = { a };
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+ let x = function () {
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+ z.a;
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+ };
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+ return x;
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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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+function component(a) {
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+ const $ = React.useMemoCache();
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+ const c_0 = $[0] !== a;
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+ let z;
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+ if (c_0) {
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+ z = {
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+ a: a,
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+ };
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+ $[0] = a;
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+ $[1] = z;
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+ } else {
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+ z = $[1];
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+ }
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+
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+ const c_2 = $[2] !== z.a;
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+ let x;
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+
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+ if (c_2) {
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+ x = function () {
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+ z.a;
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+ };
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+
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+ $[2] = z.a;
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+ $[3] = x;
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+ } else {
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+ x = $[3];
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+ }
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+
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+ return x;
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+}
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+
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+```
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+
\ No newline at end of file
compiler/forget/src/__tests__/fixtures/hir/capturing-member-expr.js
new
+7
@@ -0,0 +1,7 @@
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+function component(a) {
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+ let z = { a };
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+ let x = function () {
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+ z.a;
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+ };
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+ return x;
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+}
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-call.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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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ z.a.a();
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+ };
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+ return x;
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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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+function component(a) {
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+ const $ = React.useMemoCache();
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+ const c_0 = $[0] !== a;
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+ let t1;
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+ if (c_0) {
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+ t1 = {
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+ a: a,
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+ };
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+ $[0] = a;
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+ $[1] = t1;
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+ } else {
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+ t1 = $[1];
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+ }
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+
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+ const c_2 = $[2] !== t1;
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+ let z;
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+
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+ if (c_2) {
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+ z = {
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+ a: t1,
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+ };
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+ $[2] = t1;
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+ $[3] = z;
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+ } else {
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+ z = $[3];
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+ }
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+
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+ const c_4 = $[4] !== z.a.a;
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+ let x;
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+
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+ if (c_4) {
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+ x = function () {
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+ z.a.a();
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+ };
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+
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+ $[4] = z.a.a;
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+ $[5] = x;
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+ } else {
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+ x = $[5];
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+ }
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+
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+ return x;
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+}
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+
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+```
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+
\ No newline at end of file
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-call.js
new
+7
@@ -0,0 +1,7 @@
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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ z.a.a();
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+ };
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+ return x;
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+}
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-expr-in-nested-func.expect.md
new
+67
@@ -0,0 +1,67 @@
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+
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+## Input
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+
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+```javascript
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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ (function () {
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+ z.a.a;
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+ })();
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+ };
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+ return x;
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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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+function component(a) {
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+ const $ = React.useMemoCache();
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+ const c_0 = $[0] !== a;
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+ let t1;
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+ if (c_0) {
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+ t1 = {
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+ a: a,
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+ };
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+ $[0] = a;
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+ $[1] = t1;
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+ } else {
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+ t1 = $[1];
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+ }
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+
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+ const c_2 = $[2] !== t1;
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+ let z;
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+
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+ if (c_2) {
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+ z = {
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+ a: t1,
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+ };
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+ $[2] = t1;
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+ $[3] = z;
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+ } else {
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+ z = $[3];
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+ }
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+
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+ const c_4 = $[4] !== z.a.a;
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+ let x;
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+
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+ if (c_4) {
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+ x = function () {
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+ (function () {
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+ z.a.a;
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+ })();
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+ };
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+
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+ $[4] = z.a.a;
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+ $[5] = x;
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+ } else {
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+ x = $[5];
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+ }
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+
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+ return x;
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+}
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+
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+```
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+
\ No newline at end of file
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-expr-in-nested-func.js
new
+9
@@ -0,0 +1,9 @@
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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ (function () {
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+ z.a.a;
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+ })();
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+ };
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+ return x;
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+}
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-expr.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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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ z.a.a;
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+ };
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+ return x;
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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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+function component(a) {
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+ const $ = React.useMemoCache();
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+ const c_0 = $[0] !== a;
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+ let t1;
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+ if (c_0) {
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+ t1 = {
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+ a: a,
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+ };
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+ $[0] = a;
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+ $[1] = t1;
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+ } else {
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+ t1 = $[1];
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+ }
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+
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+ const c_2 = $[2] !== t1;
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+ let z;
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+
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+ if (c_2) {
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+ z = {
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+ a: t1,
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+ };
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+ $[2] = t1;
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+ $[3] = z;
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+ } else {
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+ z = $[3];
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+ }
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+
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+ const c_4 = $[4] !== z.a.a;
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+ let x;
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+
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+ if (c_4) {
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+ x = function () {
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+ z.a.a;
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+ };
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+
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+ $[4] = z.a.a;
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+ $[5] = x;
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+ } else {
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+ x = $[5];
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+ }
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+
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+ return x;
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+}
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+
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+```
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+
\ No newline at end of file
compiler/forget/src/__tests__/fixtures/hir/capturing-nested-member-expr.js
new
+7
@@ -0,0 +1,7 @@
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+function component(a) {
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+ let z = { a: { a } };
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+ let x = function () {
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+ z.a.a;
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+ };
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+ return x;
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+}