Removes unused v2 default import (#23)

Author: trivikr

.changeset/sweet-laws-lick.md

@@ -0,0 +1,5 @@
+---
+"aws-sdk-js-codemod": patch
+---
+
+Removes unused v2 default import

README.md

@@ -44,8 +44,6 @@ client.listTables({}, (err, data) => {
 $ npx aws-sdk-js-codemod -t v2-to-v3 example.ts
 
 $ cat example.ts
-import AWS from "aws-sdk";
-
 import { DynamoDB } from "@aws-sdk/client-dynamodb";
 
 const region = "us-west-2";

src/transforms/v2-to-v3/__testfixtures__/basic.output.ts

@@ -1,5 +1,3 @@
-import AWS from "aws-sdk";
-
 import { DynamoDB } from "@aws-sdk/client-dynamodb";
 
 const region = "us-west-2";

src/transforms/v2-to-v3/transformer.ts

@@ -1,12 +1,12 @@
 import { API, FileInfo } from "jscodeshift";
-import findImports from "jscodeshift-find-imports";
 
 import {
   addV3ClientImport,
   getV2ClientNames,
   getV2DefaultImportName,
   getV3ClientName,
   getV3ClientPackageName,
+  removeDefaultImportIfNotUsed,
   replaceClientCreation,
 } from "./utils";
 
@@ -32,5 +32,7 @@ export default function transformer(file: FileInfo, api: API) {
     });
   }
 
+  removeDefaultImportIfNotUsed(j, source, v2DefaultImportName);
+
   return source.toSource();
 }

src/transforms/v2-to-v3/utils/index.ts

@@ -3,4 +3,5 @@ export * from "./getV2ClientNames";
 export * from "./getV2DefaultImportName";
 export * from "./getV3ClientName";
 export * from "./getV3ClientPackageName";
+export * from "./removeDefaultImportIfNotUsed";
 export * from "./replaceClientCreation";

src/transforms/v2-to-v3/utils/removeDefaultImportIfNotUsed.ts

@@ -0,0 +1,31 @@
+import { Collection, JSCodeshift } from "jscodeshift";
+
+export const removeDefaultImportIfNotUsed = (
+  j: JSCodeshift,
+  source: Collection<any>,
+  defaultImportName: string
+) => {
+  const identifierUsages = source
+    .find(j.Identifier, { name: defaultImportName })
+    // Ignore identifier from import.
+    .filter((identifierPath) => identifierPath.parentPath.value.type !== "ImportDefaultSpecifier");
+
+  if (identifierUsages.size() === 0) {
+    source
+      .find(j.ImportDeclaration, {
+        specifiers: [{ type: "ImportDefaultSpecifier", local: { name: defaultImportName } }],
+      })
+      .forEach((declerationPath) => {
+        // Remove default import from ImportDecleration.
+        declerationPath.value.specifiers = declerationPath.value.specifiers.filter(
+          (specifier) =>
+            specifier.type !== "ImportDefaultSpecifier" &&
+            specifier.local.name !== defaultImportName
+        );
+        // Remove ImportDeclaration if there are no other imports.
+        if (declerationPath.value.specifiers.length === 0) {
+          j(declerationPath).remove();
+        }
+      });
+  }
+};