avoids inserting an import specifier if it already exists

Author: Daniel Del Core

.changeset/mighty-rules-drop.md

@@ -0,0 +1,5 @@
+---
+'@codeshift/utils': patch
+---
+
+insertImportSpecifier no longer adds duplicate entries if it already exists

packages/utils/src/imports.spec.ts

@@ -41,6 +41,26 @@ describe('imports', () => {
       expect(result).toMatchInlineSnapshot(`"import { bar } from 'bar';"`);
     });
 
+    it('does not insert an import specifier if already exists', async () => {
+      const transform = (file: FileInfo, api: API) => {
+        const j = api.jscodeshift;
+        const source = j(file.source);
+        importUtils.insertImportSpecifier(
+          j,
+          source,
+          j.importSpecifier(j.identifier('bar')),
+          'bar',
+        );
+
+        return source.toSource();
+      };
+      const result = await applyTransform(
+        transform,
+        `import { bar } from 'bar';`,
+      );
+      expect(result).toMatchInlineSnapshot(`"import { bar } from 'bar';"`);
+    });
+
     it('maintains a reference to importDec and is able to inserts import specifier', async () => {
       const transform = (file: FileInfo, api: API) => {
         const j = api.jscodeshift;

packages/utils/src/imports.ts

@@ -119,14 +119,21 @@ export function hasImportSpecifier(
 export function insertImportSpecifier(
   j: core.JSCodeshift,
   source: Collection<any>,
-  importSpecifier: ImportSpecifier | ImportDefaultSpecifier,
+  specifier: ImportSpecifier | ImportDefaultSpecifier,
   sourcePath: string,
 ) {
   const importDeclaration = getImportDeclaration(j, source, sourcePath);
 
   if (!importDeclaration) return;
 
-  importDeclaration.get().value.specifiers.push(importSpecifier);
+  if (
+    specifier.type === 'ImportSpecifier' &&
+    hasImportSpecifier(j, source, specifier.imported.name, sourcePath)
+  ) {
+    return;
+  }
+
+  importDeclaration.get().value.specifiers.push(specifier);
 }
 
 export function removeImportSpecifier(