fix: do not skip pattern binding referencing id

babel · Oct 13, 2021 · 947c7e1 · 947c7e1
1 parent 4130dc5
commit 947c7e1
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Showing 2 changed files with 55 additions and 13 deletions.
diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
@@ -1125,9 +1125,14 @@ export default class Scope {
         // That is, if a scope path is pattern, its parent must be Function/CatchClause
 
         // Spec 9.2.10.28: The closure created by this expression should not have visibility of
-        // declarations in the function body. If the binding is not a `param`-kind,
+        // declarations in the function body. If the binding is not a `param`-kind (as function parameters)
+        // or `local`-kind (as id in function expression),
         // then it must be defined inside the function body, thus it should be skipped
-        if (previousPath?.isPattern() && binding.kind !== "param") {
+        if (
+          previousPath?.isPattern() &&
+          binding.kind !== "param" &&
+          binding.kind !== "local"
+        ) {
           // do nothing
         } else {
           return binding;

diff --git a/packages/babel-traverse/test/scope.js b/packages/babel-traverse/test/scope.js
@@ -432,17 +432,54 @@ describe("scope", () => {
       ).toBe("_foo3");
     });
 
-    it("reference paths", function () {
-      const path = getIdentifierPath("function square(n) { return n * n}");
-      const referencePaths = path.context.scope.bindings.n.referencePaths;
-      expect(referencePaths).toHaveLength(2);
-      expect(referencePaths[0].node.loc.start).toEqual({
-        line: 1,
-        column: 28,
-      });
-      expect(referencePaths[1].node.loc.start).toEqual({
-        line: 1,
-        column: 32,
+    describe("reference paths", () => {
+      it("param referenced in function body", function () {
+        const path = getIdentifierPath("function square(n) { return n * n}");
+        const referencePaths = path.context.scope.bindings.n.referencePaths;
+        expect(referencePaths).toHaveLength(2);
+        expect(referencePaths[0].node.loc.start).toEqual({
+          line: 1,
+          column: 28,
+        });
+        expect(referencePaths[1].node.loc.start).toEqual({
+          line: 1,
+          column: 32,
+        });
+      });
+      it("id referenced in function body", () => {
+        const path = getIdentifierPath("(function n(m) { return n })");
+        const { referencePaths, identifier } = path.scope.getOwnBinding("n");
+        expect(identifier.start).toMatchInlineSnapshot(`10`);
+        expect(referencePaths).toHaveLength(1);
+        expect(referencePaths[0].node.start).toMatchInlineSnapshot(`24`);
+      });
+      it("id referenced in param initializer - function expression", () => {
+        const path = getIdentifierPath("(function n(m = n) {})");
+        const { referencePaths, identifier } = path.scope.getOwnBinding("n");
+        expect(identifier.start).toMatchInlineSnapshot(`10`);
+        expect(referencePaths).toHaveLength(1);
+        expect(referencePaths[0].node.start).toMatchInlineSnapshot(`16`);
+      });
+      it("id referenced in param initializer - function declaration", () => {
+        const path = getIdentifierPath("function n(m = n) {}");
+        const { referencePaths, identifier } = path.scope.getBinding("n");
+        expect(identifier.start).toMatchInlineSnapshot(`9`);
+        expect(referencePaths).toHaveLength(1);
+        expect(referencePaths[0].node.start).toMatchInlineSnapshot(`15`);
+      });
+      it("param referenced in function body with id collision", () => {
+        const path = getIdentifierPath("(function n(n) { return n })");
+        const { referencePaths, identifier } = path.scope.getOwnBinding("n");
+        expect(identifier.start).toMatchInlineSnapshot(`12`);
+        expect(referencePaths).toHaveLength(1);
+        expect(referencePaths[0].node.start).toMatchInlineSnapshot(`24`);
+      });
+      it("param referenced in param initializer with id collision", () => {
+        const path = getIdentifierPath("(function n(n, m = n) {})");
+        const { referencePaths, identifier } = path.scope.getOwnBinding("n");
+        expect(identifier.start).toMatchInlineSnapshot(`12`);
+        expect(referencePaths).toHaveLength(1);
+        expect(referencePaths[0].node.start).toMatchInlineSnapshot(`19`);
       });
     });