fix: remove bindings defined in blockScope when wrapped in closure

babel · Aug 16, 2019 · 0db9416 · 0db9416
1 parent 1f95f2e
commit 0db9416
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Showing 4 changed files with 53 additions and 7 deletions.
diff --git a/packages/babel-plugin-transform-block-scoping/src/index.js b/packages/babel-plugin-transform-block-scoping/src/index.js
@@ -441,20 +441,25 @@ class BlockScoping {
   }
 
   updateScopeInfo(wrappedInClosure) {
-    const scope = this.scope;
+    const blockScope = this.blockPath.scope;
 
-    const parentScope = scope.getFunctionParent() || scope.getProgramParent();
+    const parentScope =
+      blockScope.getFunctionParent() || blockScope.getProgramParent();
     const letRefs = this.letReferences;
 
     for (const key of Object.keys(letRefs)) {
       const ref = letRefs[key];
-      const binding = scope.getBinding(ref.name);
+      const binding = blockScope.getBinding(ref.name);
       if (!binding) continue;
       if (binding.kind === "let" || binding.kind === "const") {
         binding.kind = "var";
 
-        if (!wrappedInClosure) {
-          scope.moveBindingTo(ref.name, parentScope);
+        if (wrappedInClosure) {
+          if (blockScope.hasOwnBinding(ref.name)) {
+            blockScope.removeBinding(ref.name);
+          }
+        } else {
+          blockScope.moveBindingTo(ref.name, parentScope);
         }
       }
     }

diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/exec.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/exec.js
@@ -0,0 +1,34 @@
+const code = multiline([
+  "for (const {foo, ...bar} of { bar: [] }) {",
+    "() => foo;",
+    "const [qux] = bar;",
+    "try {} catch (e) {",
+      "let quux = qux;",
+    "}",
+  "}"
+]);
+
+transform(code, {
+  configFile: false,
+  plugins: [
+    "../../../../lib",
+    {
+      post({ path }) {
+        path.traverse({
+          Program(path) {
+            expect(Object.keys(path.scope.bindings)).toEqual(["foo", "bar"]);
+          },
+          ForOfStatement(path) {
+            // for declarations should be transformed to for bindings
+            expect(path.scope.bindings).toEqual({});
+            // The body should be wrapped into closure
+            expect(path.get("body").scope.bindings).toEqual({});
+          },
+          FunctionExpression(path) {
+            expect(Object.keys(path.scope.bindings)).toEqual(["foo", "bar", "qux", "quux"]);
+          }
+        })
+      }
+    }
+  ]
+});
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/input.js
@@ -1,4 +1,7 @@
 for (const {foo, ...bar} of {}) {
   () => foo;
-  bar;
+  const [qux] = bar;
+  try {} catch (e) {
+    const quux = qux;
+  }
 }
diff --git a/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js b/packages/babel-plugin-transform-block-scoping/test/fixtures/general/issue-10339/output.js
@@ -3,7 +3,11 @@ function _objectWithoutPropertiesLoose(source, excluded) { if (source == null) r
 var _loop = function (foo, bar) {
   () => foo;
 
-  bar;
+  var [qux] = bar;
+
+  try {} catch (e) {
+    var quux = qux;
+  }
 };
 
 for (var _ref of {}) {