fix(amazonq): normalize line endings to match local file endings in strReplace

server/aws-lsp-codewhisperer/src/language-server/agenticChat/tools/fsWrite.test.ts

@@ -7,6 +7,7 @@ import { InvokeOutput } from './toolShared'
 import { TestFeatures } from '@aws/language-server-runtimes/testing'
 import { Workspace } from '@aws/language-server-runtimes/server-interface'
 import { StubbedInstance } from 'ts-sinon'
+import * as os from 'os'
 
 describe('FsWrite Tool', function () {
     let tempFolder: testFolder.TestFolder
@@ -392,4 +393,125 @@ describe('FsWrite Tool', function () {
             await assert.rejects(() => fsWrite.invoke(params), /no such file or directory/)
         })
     })
+
+    describe('getStrReplaceContent', function () {
+        it('preserves CRLF line endings in file when oldStr uses LF', async () => {
+            const filePath = await tempFolder.write('test1.txt', 'before\r\nline 1\r\nline 2\r\nline 3\r\nafter')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'line 1\nline 2\nline 3',
+                newStr: 'new line 1\nnew line 2\nnew line 3',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'before\r\nnew line 1\r\nnew line 2\r\nnew line 3\r\nafter')
+        })
+
+        it('preserves LF line endings in file when oldStr uses CRLF', async () => {
+            const filePath = await tempFolder.write('test2.txt', 'before\nline 1\nline 2\nline 3\nafter')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'line 1\r\nline 2\r\nline 3',
+                newStr: 'new line 1\r\nnew line 2\r\nnew line 3',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'before\nnew line 1\nnew line 2\nnew line 3\nafter')
+        })
+
+        it('preserves CR line endings in file when oldStr uses LF', async () => {
+            const filePath = await tempFolder.write('test3.txt', 'before\rline 1\rline 2\rline 3\rafter')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'line 1\nline 2\nline 3',
+                newStr: 'new line 1\nnew line 2\nnew line 3',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'before\rnew line 1\rnew line 2\rnew line 3\rafter')
+        })
+
+        it('handles mixed line endings in newStr by normalizing to file line ending', async () => {
+            const filePath = await tempFolder.write('test4.txt', 'before\r\nline 1\r\nline 2\r\nafter')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'line 1\nline 2',
+                newStr: 'new line 1\r\nnew line 2\nnew line 3\rend',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'before\r\nnew line 1\r\nnew line 2\r\nnew line 3\r\nend\r\nafter')
+        })
+
+        it('handles content with no line endings', async () => {
+            const filePath = await tempFolder.write('test5.txt', 'before simple text after')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'simple text',
+                newStr: 'replacement',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'before replacement after')
+        })
+
+        it('uses OS default line ending when file has no line endings and adding new lines', async () => {
+            const filePath = await tempFolder.write('test6.txt', 'before text after')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'text',
+                newStr: 'line 1\nline 2',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, `before line 1${os.EOL}line 2 after`)
+        })
+
+        it('preserves line endings when only portion of line is replaced', async () => {
+            const filePath = await tempFolder.write('test8.txt', 'start\r\nprefix middle suffix\r\nend')
+
+            const params: StrReplaceParams = {
+                command: 'strReplace',
+                path: filePath,
+                oldStr: 'middle',
+                newStr: 'center',
+            }
+
+            const fsWrite = new FsWrite(features)
+            await fsWrite.invoke(params)
+
+            const result = await features.workspace.fs.readFile(filePath)
+            assert.strictEqual(result, 'start\r\nprefix center suffix\r\nend')
+        })
+    })
 })

server/aws-lsp-codewhisperer/src/language-server/agenticChat/tools/fsWrite.ts

@@ -1,10 +1,7 @@
-import { workspaceUtils } from '@aws/lsp-core'
 import { CommandValidation, ExplanatoryParams, InvokeOutput, requiresPathAcceptance } from './toolShared'
 import { Features } from '@aws/language-server-runtimes/server-interface/server'
 import { sanitize } from '@aws/lsp-core/out/util/path'
-import { Change, diffLines } from 'diff'
-import { URI } from 'vscode-uri'
-import { getWorkspaceFolderPaths } from '@aws/lsp-core/out/util/workspaceUtils'
+import * as os from 'os'
 
 // Port of https://github.com/aws/aws-toolkit-vscode/blob/16aa8768834f41ae512522473a6a962bb96abe51/packages/core/src/codewhispererChat/tools/fsWrite.ts#L42
 
@@ -259,7 +256,15 @@ const getInsertContent = (params: InsertParams, oldContent: string) => {
 }
 
 const getStrReplaceContent = (params: StrReplaceParams, oldContent: string) => {
-    const matches = [...oldContent.matchAll(new RegExp(escapeRegExp(params.oldStr), 'g'))]
+    // Detect line ending from oldContent (CRLF, LF, or CR)
+    const match = oldContent.match(/\r\n|\r|\n/)
+    const lineEnding = match ? match[0] : os.EOL
+
+    // Normalize oldStr and newStr to match oldContent's line ending style
+    const normalizedOldStr = params.oldStr.split(/\r\n|\r|\n/).join(lineEnding)
+    const normalizedNewStr = params.newStr.split(/\r\n|\r|\n/).join(lineEnding)
+
+    const matches = [...oldContent.matchAll(new RegExp(escapeRegExp(normalizedOldStr), 'g'))]
 
     if (matches.length === 0) {
         throw new Error(`No occurrences of "${params.oldStr}" were found`)
@@ -268,7 +273,7 @@ const getStrReplaceContent = (params: StrReplaceParams, oldContent: string) => {
         throw new Error(`${matches.length} occurrences of oldStr were found when only 1 is expected`)
     }
 
-    return oldContent.replace(params.oldStr, params.newStr)
+    return oldContent.replace(normalizedOldStr, normalizedNewStr)
 }
 
 const escapeRegExp = (string: string) => {