From f4d249796803b2be0e715024c0dd2076a02d6e41 Mon Sep 17 00:00:00 2001
From: Trivikram Kamat <16024985+trivikr@users.noreply.github.com>
Date: Wed, 26 Jul 2023 15:04:01 -0700
Subject: [PATCH] Preserve import comments when transforming code (#514)

---
 .changeset/dirty-owls-turn.md                 |  5 +++++
 .../global-import-equals.block.input.ts       |  6 +++++
 .../global-import-equals.block.output.ts      | 10 +++++++++
 .../global-import-equals.inline.input.ts      |  4 ++++
 .../global-import-equals.inline.output.ts     |  8 +++++++
 .../global-import.block.input.js              |  6 +++++
 .../global-import.block.output.js             |  6 +++++
 .../global-import.inline.input.js             |  4 ++++
 .../global-import.inline.output.js            |  4 ++++
 .../global-require.block.input.js             |  6 +++++
 .../global-require.block.output.js            |  8 +++++++
 .../global-require.inline.input.js            |  4 ++++
 .../global-require.inline.output.js           |  6 +++++
 .../service-import.block.input.js             |  6 +++++
 .../service-import.block.output.js            |  6 +++++
 .../service-import.inline.input.js            |  4 ++++
 .../service-import.inline.output.js           |  4 ++++
 .../service-require.block.input.js            |  6 +++++
 .../service-require.block.output.js           |  8 +++++++
 .../service-require.inline.input.js           |  4 ++++
 .../service-require.inline.output.js          |  6 +++++
 .../modules/removeImportDeclaration.ts        | 19 ++++++++++++++++
 .../v2-to-v3/modules/removeImportDefault.ts   |  3 ++-
 .../v2-to-v3/modules/removeImportEquals.ts    | 22 ++++++++++---------
 .../v2-to-v3/modules/removeImportNamed.ts     |  3 ++-
 25 files changed, 156 insertions(+), 12 deletions(-)
 create mode 100644 .changeset/dirty-owls-turn.md
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.input.ts
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.output.ts
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.input.ts
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.output.ts
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.output.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.input.js
 create mode 100644 src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.output.js
 create mode 100644 src/transforms/v2-to-v3/modules/removeImportDeclaration.ts

diff --git a/.changeset/dirty-owls-turn.md b/.changeset/dirty-owls-turn.md
new file mode 100644
index 000000000..b1a04d071
--- /dev/null
+++ b/.changeset/dirty-owls-turn.md
@@ -0,0 +1,5 @@
+---
+"aws-sdk-js-codemod": patch
+---
+
+Preserve import comments when transforming code
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.input.ts b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.input.ts
new file mode 100644
index 000000000..03c83fac7
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.input.ts
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+import AWS = require("aws-sdk");
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.output.ts b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.output.ts
new file mode 100644
index 000000000..fdbb1c09a
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.block.output.ts
@@ -0,0 +1,10 @@
+/*
+ * Example comment which should not be removed.
+ */
+import AWS_DynamoDB = require("@aws-sdk/client-dynamodb");
+
+const {
+ DynamoDB
+} = AWS_DynamoDB;
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.input.ts b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.input.ts
new file mode 100644
index 000000000..320e5436d
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.input.ts
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+import AWS = require("aws-sdk");
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.output.ts b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.output.ts
new file mode 100644
index 000000000..4f7f2b243
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import-equals.inline.output.ts
@@ -0,0 +1,8 @@
+// Example comment which should not be removed.
+import AWS_DynamoDB = require("@aws-sdk/client-dynamodb");
+
+const {
+  DynamoDB
+} = AWS_DynamoDB;
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.input.js
new file mode 100644
index 000000000..78482dd92
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.input.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+import AWS from "aws-sdk";
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.output.js
new file mode 100644
index 000000000..203ccb7f1
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.block.output.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+import { DynamoDB } from "@aws-sdk/client-dynamodb";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.input.js
new file mode 100644
index 000000000..7833d886f
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.input.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+import AWS from "aws-sdk";
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.output.js
new file mode 100644
index 000000000..593906ff5
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-import.inline.output.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+import { DynamoDB } from "@aws-sdk/client-dynamodb";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.input.js
new file mode 100644
index 000000000..1e0dd2509
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.input.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+const AWS = require("aws-sdk");
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.output.js
new file mode 100644
index 000000000..29fadad6e
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.block.output.js
@@ -0,0 +1,8 @@
+/*
+ * Example comment which should not be removed.
+ */
+const {
+ DynamoDB
+} = require("@aws-sdk/client-dynamodb");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.input.js
new file mode 100644
index 000000000..16c903473
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.input.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+const AWS = require("aws-sdk");
+
+const client = new AWS.DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.output.js
new file mode 100644
index 000000000..806cb0219
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/global-require.inline.output.js
@@ -0,0 +1,6 @@
+// Example comment which should not be removed.
+const {
+  DynamoDB
+} = require("@aws-sdk/client-dynamodb");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.input.js
new file mode 100644
index 000000000..16fc25f69
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.input.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+import { DynamoDB } from "aws-sdk";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.output.js
new file mode 100644
index 000000000..203ccb7f1
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.block.output.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+import { DynamoDB } from "@aws-sdk/client-dynamodb";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.input.js
new file mode 100644
index 000000000..7dd3ccf1c
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.input.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+import { DynamoDB } from "aws-sdk";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.output.js
new file mode 100644
index 000000000..593906ff5
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-import.inline.output.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+import { DynamoDB } from "@aws-sdk/client-dynamodb";
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.input.js
new file mode 100644
index 000000000..36e12a4a8
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.input.js
@@ -0,0 +1,6 @@
+/*
+ * Example comment which should not be removed.
+ */
+const { DynamoDB } = require("aws-sdk");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.output.js
new file mode 100644
index 000000000..29fadad6e
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.block.output.js
@@ -0,0 +1,8 @@
+/*
+ * Example comment which should not be removed.
+ */
+const {
+ DynamoDB
+} = require("@aws-sdk/client-dynamodb");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.input.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.input.js
new file mode 100644
index 000000000..77f400de6
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.input.js
@@ -0,0 +1,4 @@
+// Example comment which should not be removed.
+const { DynamoDB } = require("aws-sdk");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.output.js b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.output.js
new file mode 100644
index 000000000..806cb0219
--- /dev/null
+++ b/src/transforms/v2-to-v3/__fixtures__/import-comments/service-require.inline.output.js
@@ -0,0 +1,6 @@
+// Example comment which should not be removed.
+const {
+  DynamoDB
+} = require("@aws-sdk/client-dynamodb");
+
+const client = new DynamoDB();
\ No newline at end of file
diff --git a/src/transforms/v2-to-v3/modules/removeImportDeclaration.ts b/src/transforms/v2-to-v3/modules/removeImportDeclaration.ts
new file mode 100644
index 000000000..67cb1d1e7
--- /dev/null
+++ b/src/transforms/v2-to-v3/modules/removeImportDeclaration.ts
@@ -0,0 +1,19 @@
+import { ASTPath, ImportDeclaration, JSCodeshift } from "jscodeshift";
+
+/**
+ * Removes import declaration, but preserves comments by adding them to next sibling.
+ */
+export const removeImportDeclaration = (
+  j: JSCodeshift,
+  declarationPath: ASTPath<ImportDeclaration>
+) => {
+  const { comments } = declarationPath.value;
+  if (comments?.length) {
+    const siblings = declarationPath.parent?.value.body;
+    if (siblings?.length) {
+      const nextSibling = siblings[siblings.indexOf(declarationPath.value) + 1];
+      nextSibling.comments = [...comments, ...(nextSibling.comments || [])];
+    }
+  }
+  j(declarationPath).remove();
+};
diff --git a/src/transforms/v2-to-v3/modules/removeImportDefault.ts b/src/transforms/v2-to-v3/modules/removeImportDefault.ts
index aeff68a47..485c1acb0 100644
--- a/src/transforms/v2-to-v3/modules/removeImportDefault.ts
+++ b/src/transforms/v2-to-v3/modules/removeImportDefault.ts
@@ -1,4 +1,5 @@
 import { Collection, JSCodeshift } from "jscodeshift";
+import { removeImportDeclaration } from "./removeImportDeclaration";
 
 export interface RemoveImportDefaultOptions {
   localName: string;
@@ -26,7 +27,7 @@ export const removeImportDefault = (
 
       // Remove ImportDeclaration if there are no import specifiers.
       if (declarationPath.value.specifiers?.length === 0) {
-        j(declarationPath).remove();
+        removeImportDeclaration(j, declarationPath);
       }
     });
 };
diff --git a/src/transforms/v2-to-v3/modules/removeImportEquals.ts b/src/transforms/v2-to-v3/modules/removeImportEquals.ts
index 3786587e2..444616779 100644
--- a/src/transforms/v2-to-v3/modules/removeImportEquals.ts
+++ b/src/transforms/v2-to-v3/modules/removeImportEquals.ts
@@ -1,4 +1,5 @@
 import { Collection, JSCodeshift } from "jscodeshift";
+import { removeImportDeclaration } from "./removeImportDeclaration";
 
 export interface RemoveImportEqualsOptions {
   localName: string;
@@ -10,14 +11,15 @@ export const removeImportEquals = (
   source: Collection<unknown>,
   { localName, sourceValue }: RemoveImportEqualsOptions
 ) => {
-  source
-    .find(j.TSImportEqualsDeclaration, {
-      type: "TSImportEqualsDeclaration",
-      id: { name: localName },
-      moduleReference: {
-        type: "TSExternalModuleReference",
-        expression: { type: "StringLiteral", value: sourceValue },
-      },
-    })
-    .remove();
+  const importEqualsDeclaration = source.find(j.TSImportEqualsDeclaration, {
+    type: "TSImportEqualsDeclaration",
+    id: { name: localName },
+    moduleReference: {
+      type: "TSExternalModuleReference",
+      expression: { type: "StringLiteral", value: sourceValue },
+    },
+  });
+  if (importEqualsDeclaration.length) {
+    removeImportDeclaration(j, importEqualsDeclaration.get());
+  }
 };
diff --git a/src/transforms/v2-to-v3/modules/removeImportNamed.ts b/src/transforms/v2-to-v3/modules/removeImportNamed.ts
index 347d7ea41..a2b7e1c27 100644
--- a/src/transforms/v2-to-v3/modules/removeImportNamed.ts
+++ b/src/transforms/v2-to-v3/modules/removeImportNamed.ts
@@ -1,4 +1,5 @@
 import { Collection, JSCodeshift } from "jscodeshift";
+import { removeImportDeclaration } from "./removeImportDeclaration";
 
 export interface RemoveImportNamedOptions {
   importedName?: string;
@@ -36,7 +37,7 @@ export const removeImportNamed = (
 
       // Remove ImportDeclaration if there are no import specifiers.
       if (declarationPath.value.specifiers?.length === 0) {
-        j(declarationPath).remove();
+        removeImportDeclaration(j, declarationPath);
       }
     });
 };