fix: improve variable declarator removal (#16587)

* fix: fixed issue16583 + test * modified getBinding to getOwnBinding (same scope) * reverted babel-plugin-proposal-do-expressions back * refactor: moved fix from scope/index.ts to path/removal.ts * add fail test * fix * review * Update packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/plugin.js Co-authored-by: Nicolò Ribaudo <hello@nicr.dev> * review * Update packages/babel-traverse/src/path/lib/removal-hooks.ts --------- Co-authored-by: Babel Bot <30521560+liuxingbaoyu@users.noreply.github.com> Co-authored-by: Nicolò Ribaudo <hello@nicr.dev>
babel · Jul 27, 2024 · 801d3cb · 801d3cb
1 parent 30b4473
commit 801d3cb
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Showing 9 changed files with 49 additions and 3 deletions.
diff --git a/packages/babel-traverse/src/path/removal.ts b/packages/babel-traverse/src/path/removal.ts
@@ -11,15 +11,16 @@ export function remove(this: NodePath) {
   _assertUnremoved.call(this);
 
   this.resync();
-  if (!this.opts?.noScope) {
-    _removeFromScope.call(this);
-  }
 
   if (_callRemovalHooks.call(this)) {
     _markRemoved.call(this);
     return;
   }
 
+  if (!this.opts?.noScope) {
+    _removeFromScope.call(this);
+  }
+
   this.shareCommentsWithSiblings();
   _remove.call(this);
   _markRemoved.call(this);

diff --git a/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/input.js b/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/input.js
@@ -0,0 +1,4 @@
+{
+  let a = 33;
+}
+let a = 42;
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/options.json b/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["./plugin"]
+}
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/output.js b/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/output.js
@@ -0,0 +1,4 @@
+{}
+let a = 42;
+/*// a is defined when visiting a=33? true*/
+/*// a is defined when visiting a=42? true*/
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/plugin.js b/packages/babel-traverse/test/fixtures/scope/remove-nested-let-path/plugin.js
@@ -0,0 +1,17 @@
+module.exports = function ({ types }) {
+  return {
+    visitor: {
+      VariableDeclarator(path) {
+        const { value } = path.node.init;
+
+        if (value === 33) path.remove();
+
+        types.addComment(
+          path.scope.getProgramParent().path.node,
+          "trailing",
+          `// a is defined when visiting a=${value}? ${path.scope.hasBinding("a")}`
+        );
+      },
+    },
+  };
+};
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/input.js b/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/input.js
@@ -0,0 +1,3 @@
+{
+  var a = 1;
+}
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/options.json b/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["./plugin"]
+}
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/output.js b/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/output.js
@@ -0,0 +1 @@
+{}
diff --git a/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/plugin.js b/packages/babel-traverse/test/fixtures/scope/remove-var-in-block/plugin.js
@@ -0,0 +1,10 @@
+module.exports = function () {
+  return {
+    visitor: {
+      VariableDeclarator(path) {
+        path.remove();
+        expect(path.scope.getBinding("a")).toBeUndefined();
+      },
+    },
+  };
+};