Refactor file processing API to a single-parameter object; improve maintainability and testability. Align tests and write-file flow with the new signature.

🤖 Generated with Codebuff
Co-Authored-By: Codebuff <noreply@codebuff.com>

Author: charleslien

backend/src/__tests__/main-prompt.test.ts

@@ -96,12 +96,11 @@ describe('mainPrompt', () => {
 
     // Mock processFileBlock
     spyOn(processFileBlockModule, 'processFileBlock').mockImplementation(
-      async (path, instructions, contentPromise, newContent) => {
+      async (params) => {
         return {
           tool: 'write_file' as const,
-          path,
-          instructions,
-          content: newContent,
+          path: params.path,
+          content: params.newContent,
           patch: undefined,
           messages: [],
         }

backend/src/__tests__/process-file-block.test.ts

@@ -75,19 +75,19 @@ describe('processFileBlockModule', () => {
         '```typescript\nfunction test() {\n  return true;\n}\n```'
       const expectedContent = 'function test() {\n  return true;\n}'
 
-      const result = await processFileBlock(
-        'test.ts',
-        undefined,
-        Promise.resolve(null),
+      const result = await processFileBlock({
+        path: 'test.ts',
+        instructions: undefined,
+        initialContentPromise: Promise.resolve(null),
         newContent,
-        [],
-        '',
-        undefined,
-        'clientSessionId',
-        'fingerprintId',
-        'userInputId',
-        TEST_USER_ID,
-      )
+        messages: [],
+        fullResponse: '',
+        lastUserPrompt: undefined,
+        clientSessionId: 'clientSessionId',
+        fingerprintId: 'fingerprintId',
+        userInputId: 'userInputId',
+        userId: TEST_USER_ID,
+      })
 
       expect(result).not.toBeNull()
       if ('error' in result) {
@@ -111,19 +111,19 @@ describe('processFileBlockModule', () => {
         '  return "See you later!";\r\n' +
         '}\r\n'
 
-      const result = await processFileBlock(
-        'test.ts',
-        undefined,
-        Promise.resolve(oldContent),
+      const result = await processFileBlock({
+        path: 'test.ts',
+        instructions: undefined,
+        initialContentPromise: Promise.resolve(oldContent),
         newContent,
-        [],
-        '',
-        undefined,
-        'clientSessionId',
-        'fingerprintId',
-        'userInputId',
-        TEST_USER_ID,
-      )
+        messages: [],
+        fullResponse: '',
+        lastUserPrompt: undefined,
+        clientSessionId: 'clientSessionId',
+        fingerprintId: 'fingerprintId',
+        userInputId: 'userInputId',
+        userId: TEST_USER_ID,
+      })
 
       expect(result).not.toBeNull()
       if ('error' in result) {
@@ -143,19 +143,19 @@ describe('processFileBlockModule', () => {
       const oldContent = 'function test() {\n  return true;\n}\n'
       const newContent = 'function test() {\n  return true;\n}\n'
 
-      const result = await processFileBlock(
-        'test.ts',
-        undefined,
-        Promise.resolve(oldContent),
+      const result = await processFileBlock({
+        path: 'test.ts',
+        instructions: undefined,
+        initialContentPromise: Promise.resolve(oldContent),
         newContent,
-        [],
-        '',
-        undefined,
-        'clientSessionId',
-        'fingerprintId',
-        'userInputId',
-        TEST_USER_ID,
-      )
+        messages: [],
+        fullResponse: '',
+        lastUserPrompt: undefined,
+        clientSessionId: 'clientSessionId',
+        fingerprintId: 'fingerprintId',
+        userInputId: 'userInputId',
+        userId: TEST_USER_ID,
+      })
 
       expect(result).not.toBeNull()
       expect('error' in result).toBe(true)
@@ -168,19 +168,19 @@ describe('processFileBlockModule', () => {
       const oldContent = 'const x = 1;\r\nconst y = 2;\r\n'
       const newContent = 'const x = 1;\r\nconst z = 3;\r\n'
 
-      const result = await processFileBlock(
-        'test.ts',
-        undefined,
-        Promise.resolve(oldContent),
+      const result = await processFileBlock({
+        path: 'test.ts',
+        instructions: undefined,
+        initialContentPromise: Promise.resolve(oldContent),
         newContent,
-        [],
-        '',
-        undefined,
-        'clientSessionId',
-        'fingerprintId',
-        'userInputId',
-        TEST_USER_ID,
-      )
+        messages: [],
+        fullResponse: '',
+        lastUserPrompt: undefined,
+        clientSessionId: 'clientSessionId',
+        fingerprintId: 'fingerprintId',
+        userInputId: 'userInputId',
+        userId: TEST_USER_ID,
+      })
 
       expect(result).not.toBeNull()
       if ('error' in result) {
@@ -214,19 +214,19 @@ describe('processFileBlockModule', () => {
       const newContent =
         '// ... existing code ...\nconst x = 1;\n// ... existing code ...'
 
-      const result = await processFileBlock(
-        'test.ts',
-        undefined,
-        Promise.resolve(null),
+      const result = await processFileBlock({
+        path: 'test.ts',
+        instructions: undefined,
+        initialContentPromise: Promise.resolve(null),
         newContent,
-        [],
-        '',
-        undefined,
-        'clientSessionId',
-        'fingerprintId',
-        'userInputId',
-        TEST_USER_ID,
-      )
+        messages: [],
+        fullResponse: '',
+        lastUserPrompt: undefined,
+        clientSessionId: 'clientSessionId',
+        fingerprintId: 'fingerprintId',
+        userInputId: 'userInputId',
+        userId: TEST_USER_ID,
+      })
 
       expect(result).not.toBeNull()
       expect('error' in result).toBe(true)

backend/src/process-file-block.ts

@@ -14,19 +14,19 @@ import { countTokens } from './util/token-counter'
 
 import type { Message } from '@codebuff/common/types/messages/codebuff-message'
 
-export async function processFileBlock(
-  path: string,
-  instructions: string | undefined,
-  initialContentPromise: Promise<string | null>,
-  newContent: string,
-  messages: Message[],
-  fullResponse: string,
-  lastUserPrompt: string | undefined,
-  clientSessionId: string,
-  fingerprintId: string,
-  userInputId: string,
-  userId: string | undefined,
-): Promise<
+export async function processFileBlock(params: {
+  path: string
+  instructions: string | undefined
+  initialContentPromise: Promise<string | null>
+  newContent: string
+  messages: Message[]
+  fullResponse: string
+  lastUserPrompt: string | undefined
+  clientSessionId: string
+  fingerprintId: string
+  userInputId: string
+  userId: string | undefined
+}): Promise<
   | {
       tool: 'write_file'
       path: string
@@ -40,6 +40,19 @@ export async function processFileBlock(
       error: string // Error message if the file could not be updated
     }
 > {
+  const {
+    path,
+    instructions,
+    initialContentPromise,
+    newContent,
+    messages,
+    fullResponse,
+    lastUserPrompt,
+    clientSessionId,
+    fingerprintId,
+    userInputId,
+    userId,
+  } = params
   const initialContent = await initialContentPromise
 
   if (initialContent === null) {
@@ -97,15 +110,15 @@ export async function processFileBlock(
     'Write diff created by fast-apply model. May contain errors. Make sure to double check!',
   )
   if (tokenCount > LARGE_FILE_TOKEN_LIMIT) {
-    const largeFileContent = await handleLargeFile(
-      normalizedInitialContent,
-      normalizedEditSnippet,
+    const largeFileContent = await handleLargeFile({
+      oldContent: normalizedInitialContent,
+      editSnippet: normalizedEditSnippet,
       clientSessionId,
       fingerprintId,
       userInputId,
       userId,
-      path,
-    )
+      filePath: path,
+    })
 
     if (!largeFileContent) {
       return {
@@ -211,15 +224,24 @@ export async function processFileBlock(
 
 const LARGE_FILE_TOKEN_LIMIT = 64_000
 
-export async function handleLargeFile(
-  oldContent: string,
-  editSnippet: string,
-  clientSessionId: string,
-  fingerprintId: string,
-  userInputId: string,
-  userId: string | undefined,
-  filePath: string,
-): Promise<string | null> {
+export async function handleLargeFile(params: {
+  oldContent: string
+  editSnippet: string
+  clientSessionId: string
+  fingerprintId: string
+  userInputId: string
+  userId: string | undefined
+  filePath: string
+}): Promise<string | null> {
+  const {
+    oldContent,
+    editSnippet,
+    clientSessionId,
+    fingerprintId,
+    userInputId,
+    userId,
+    filePath,
+  } = params
   const startTime = Date.now()
 
   // If the whole file is rewritten, we can just return the new content.

backend/src/tools/handlers/tool/write-file.ts

@@ -139,19 +139,19 @@ export const handleWriteFile = (({
 
   logger.debug({ path, content }, `write_file ${path}`)
 
-  const newPromise = processFileBlock(
+  const newPromise = processFileBlock({
     path,
     instructions,
-    latestContentPromise,
-    fileContentWithoutStartNewline,
-    agentMessagesUntruncated,
-    fullResponse ?? '',
-    prompt,
+    initialContentPromise: latestContentPromise,
+    newContent: fileContentWithoutStartNewline,
+    messages: agentMessagesUntruncated,
+    fullResponse: fullResponse ?? '',
+    lastUserPrompt: prompt,
     clientSessionId,
     fingerprintId,
     userInputId,
     userId,
-  )
+  })
     .catch((error) => {
       logger.error(error, 'Error processing write_file block')
       return {