Merge pull request #114 from edsrzf/fix-arrow-obj-lit

Work around jscodeshift arrow function bug
airbnb · May 1, 2021 · fd31146 · fd31146
2 parents bbeabb3 + f41f20a
commit fd31146
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Showing 2 changed files with 50 additions and 20 deletions.
diff --git a/packages/ts-migrate-plugins/src/plugins/explicit-any.ts b/packages/ts-migrate-plugins/src/plugins/explicit-any.ts
@@ -113,26 +113,44 @@ function replaceTS7006AndTS7008(
           node.typeAnnotation == null,
       )
       .forEach((path) => {
-        // Special case for single-parameter arrow surrounding parens issue.
-        if (
-          j.ArrowFunctionExpression.check(path.parent.node) &&
-          path.parent.node.params.length === 1
-        ) {
-          const paramIndex = path.parent.node.params.indexOf(path.node);
-          path.parent.replace(
-            j.arrowFunctionExpression.from({
-              ...path.parent.node,
-              params: [
-                ...path.parent.node.params.slice(0, paramIndex),
-                j.identifier.from({
-                  ...(path.parent.node.params[paramIndex] as Identifier),
-                  typeAnnotation,
-                }),
-                ...path.parent.node.params.slice(paramIndex + 1),
-              ],
-            }),
-          );
-        } else {
+        let replaceArrow = false;
+
+        const parentNode = path.parent.node;
+        if (j.ArrowFunctionExpression.check(parentNode)) {
+          // Special casing to work around jscodeshift bugs.
+          let { body, params } = parentNode;
+
+          // Object literals used as arrow function returns do not have
+          // parentheses added.
+          // https://github.com/benjamn/recast/issues/743
+          if (j.ObjectExpression.check(body)) {
+            replaceArrow = true;
+            body = j.objectExpression.from({ ...body });
+          }
+
+          // Make sure to add parentheses around single parameters.
+          if (params.length === 1) {
+            replaceArrow = true;
+            params = [
+              j.identifier.from({
+                ...(parentNode.params[0] as Identifier),
+                typeAnnotation,
+              }),
+            ];
+          }
+
+          if (replaceArrow) {
+            path.parent.replace(
+              j.arrowFunctionExpression.from({
+                ...parentNode,
+                params,
+                body,
+              }),
+            );
+          }
+        }
+
+        if (!replaceArrow) {
           path.get('typeAnnotation').replace(typeAnnotation);
         }
       });

diff --git a/packages/ts-migrate-plugins/tests/src/explicit-any.test.ts b/packages/ts-migrate-plugins/tests/src/explicit-any.test.ts
@@ -122,4 +122,16 @@ function f3(this: any) { return () => this; }
 
     expect(result).toBe(`const var1: $TSFixMe = [];`);
   });
+
+  it('handles arrow functions returning object literals', async () => {
+    const text = `const fn = (b) => ({});`;
+
+    const result = await explicitAnyPlugin.run(
+      await realPluginParams({
+        text,
+      }),
+    );
+
+    expect(result).toBe(`const fn = (b: any) => ({});`);
+  });
 });