Filter null array elements, add early return, remove optional chaining

babel · Sep 2, 2021 · ab3b603 · ab3b603
1 parent 8ace7f1
commit ab3b603
Show file tree

Hide file tree

Showing 3 changed files with 51 additions and 8 deletions.
diff --git a/packages/babel-plugin-proposal-object-rest-spread/src/index.js b/packages/babel-plugin-proposal-object-rest-spread/src/index.js
@@ -242,21 +242,25 @@ export default declare((api, opts) => {
 
   function hasMoreThanOneBinding(node) {
     // ArrayPattern
-    if (node?.elements) {
-      if (node.elements.length > 1) return true;
-      else return hasMoreThanOneBinding(node.elements[0]);
+    if (node.elements) {
+      const nonNullElements = node.elements.filter(element => element !== null);
+      if (nonNullElements.length > 1) return true;
+      else return hasMoreThanOneBinding(nonNullElements[0]);
       // ObjectPattern
-    } else if (node?.properties) {
+    } else if (node.properties) {
       if (node.properties.length > 1) return true;
+      // Case of `const {} = {}`. This shouldn't be hit as
+      // we currently call `hasMoreThanOneBinding` only under visitRestElements.
+      else if (node.properties.length === 0) return false;
       else return hasMoreThanOneBinding(node.properties[0]);
       // ObjectProperty
-    } else if (node?.value) {
-      else return hasMoreThanOneBinding(node.value);
+    } else if (node.value) {
+      return hasMoreThanOneBinding(node.value);
       // AssignmentPattern
-    } else if (node?.left) {
+    } else if (node.left) {
       return hasMoreThanOneBinding(node.left);
       // RestElement
-    } else if (node?.argument) {
+    } else if (node.argument) {
       return hasMoreThanOneBinding(node.argument);
     } else {
       // node is Identifier or MemberExpression

diff --git a/...gin-proposal-object-rest-spread/test/fixtures/object-rest/variable-destructuring/input.js b/...gin-proposal-object-rest-spread/test/fixtures/object-rest/variable-destructuring/input.js
@@ -28,3 +28,11 @@ const [[ ...y23 ] = []] = z();
 const [{ ...y24 } = []] = z();
 const { x25: [ ...y25 ] = []} = z();
 const { x26: [ q26, ...y26 ] = []} = z();
+const {} = {};
+const [,,x27] = z();
+const {x28: [,,{...y28}]} = z();
+const {x29: [,,{q29, ...y29}]} = z();
+const [,,{y30, ...x30}] = z();
+const [,,{...x31}] = z();
+const { x32: { }, w32: { ...y32 } } = z();
+const [,,{}, {...q32}] = z();
diff --git a/...in-proposal-object-rest-spread/test/fixtures/object-rest/variable-destructuring/output.js b/...in-proposal-object-rest-spread/test/fixtures/object-rest/variable-destructuring/output.js
@@ -138,3 +138,34 @@ const {
 const {
   x26: [q26, ...y26] = []
 } = z();
+const {} = {};
+const [,, x27] = z();
+
+const _z14 = z(),
+      {} = _z14,
+      y28 = babelHelpers.extends({}, _z14.x28);
+
+const _z15 = z(),
+      {
+  x29: [,, {
+    q29
+  }]
+} = _z15,
+      y29 = babelHelpers.objectWithoutProperties(_z15.x29, ["q29"]);
+
+const [,, _ref4] = z();
+const {
+  y30
+} = _ref4,
+      x30 = babelHelpers.objectWithoutProperties(_ref4, ["y30"]);
+const [,, _ref5] = z();
+const x31 = babelHelpers.extends({}, _ref5);
+
+const _z16 = z(),
+      {
+  x32: {}
+} = _z16,
+      y32 = babelHelpers.extends({}, _z16.w32);
+
+const [,, {}, _ref6] = z();
+const q32 = babelHelpers.extends({}, _ref6);