Make write_file completely deterministic. No edit snippet

Author: jahooma

.agents/types/tools.ts

@@ -178,7 +178,7 @@ export interface ProposeWriteFileParams {
   path: string
   /** What the change is intended to do in only one sentence. */
   instructions: string
-  /** Edit snippet to apply to the file. */
+  /** Complete file content to write to the file. */
   content: string
 }
 
@@ -319,14 +319,14 @@ export interface WebSearchParams {
 }
 
 /**
- * Create or edit a file with the given content.
+ * Create or overwrite a file with the given content.
  */
 export interface WriteFileParams {
   /** Path to the file relative to the **project root** */
   path: string
   /** What the change is intended to do in only one sentence. */
   instructions: string
-  /** Edit snippet to apply to the file. */
+  /** Complete file content to write to the file. */
   content: string
 }
 

agents/editor/best-of-n/editor-implementor.ts

@@ -64,7 +64,7 @@ OR for new files or major rewrites:
   "cb_tool_name": "propose_write_file",
   "path": "path/to/file",
   "instructions": "What the change does",
-  "content": "Complete file content or edit snippet"
+  "content": "Complete file content"
 }
 </codebuff_tool_call>
 ${isGpt5 || isGemini

agents/editor/editor.ts

@@ -56,7 +56,7 @@ OR for new files or major rewrites:
   "cb_tool_name": "write_file",
   "path": "path/to/file",
   "instructions": "What the change does",
-  "content": "Complete file content or edit snippet"
+  "content": "Complete file content"
 }
 </codebuff_tool_call>
 

common/src/constants/paths.ts

@@ -1,6 +1,5 @@
 export const STOP_MARKER = '[' + 'END]'
 export const FIND_FILES_MARKER = '[' + 'FIND_FILES_PLEASE]'
-export const EXISTING_CODE_MARKER = '[[**REPLACE_WITH_EXISTING_CODE**]]'
 
 // Directory where agent template override files are stored
 export const AGENT_TEMPLATES_DIR = '.agents/'

common/src/tools/params/tool/write-file.ts

@@ -16,19 +16,13 @@ const inputSchema = z
     instructions: z
       .string()
       .describe('What the change is intended to do in only one sentence.'),
-    content: z.string().describe(`Edit snippet to apply to the file.`),
+    content: z.string().describe(`Complete file content to write to the file.`),
   })
-  .describe(`Create or edit a file with the given content.`)
+  .describe(`Create or overwrite a file with the given content.`)
 const description = `
 Create or replace a file with the given content.
 
-####  Edit Snippet
-
-Format the \`content\` parameter with the entire content of the file or as an edit snippet that describes how you would like to modify the provided existing code.
-
-You may abbreviate any sections of the code in your response that will remain the same with placeholder comments: "// ... existing code ...". Abbreviate as much as possible to save the user credits!
-
-If you don't use any placeholder comments, the entire file will be replaced. E.g. don't write out a single function without using placeholder comments unless you want to replace the entire file with that function.
+Format the \`content\` parameter with the entire content of the file.
 
 #### Additional Info
 
@@ -50,28 +44,21 @@ ${$getNativeToolCallExampleString({
   endsAgentStep,
 })}
 
-Example 2 - Editing with placeholder comments:
+Example 2 - Overwriting a file:
 ${$getNativeToolCallExampleString({
   toolName,
   inputSchema,
   input: {
     path: 'foo.ts',
-    instructions: 'Update foo and remove console.log',
-    content: `// ... existing code ...
-
-function foo() {
-  console.log('foo');
-  for (let i = 0; i < 10; i++) {
-    console.log(i);
-  }
-  doSomething();
-
-  // Delete the console.log line from here
-
-  doSomethingElse();
+    instructions: 'Update foo function',
+    content: `function foo() {
+  doSomethingNew();
 }
-
-// ... existing code ...`,
+  
+function bar() {
+  doSomethingOld();
+}
+`,
   },
   endsAgentStep,
 })}

common/src/util/__tests__/string.test.ts

@@ -1,7 +1,6 @@
 import { describe, expect, it } from 'bun:test'
 
-import { EXISTING_CODE_MARKER } from '../../old-constants'
-import { pluralize, replaceNonStandardPlaceholderComments } from '../string'
+import { pluralize } from '../string'
 
 describe('pluralize', () => {
   it('should handle singular and plural cases correctly', () => {
@@ -238,90 +237,3 @@ describe('pluralize', () => {
   })
 })
 
-describe('replaceNonStandardPlaceholderComments', () => {
-  it('should replace C-style comments', () => {
-    const input = `
-function example() {
-  // ... some code ...
-  console.log('Hello');
-  // ... rest of the function ...
-}
-`
-    const expected = `
-function example() {
-  ${EXISTING_CODE_MARKER}
-  console.log('Hello');
-  ${EXISTING_CODE_MARKER}
-}
-`
-    expect(
-      replaceNonStandardPlaceholderComments(input, EXISTING_CODE_MARKER),
-    ).toBe(expected)
-  })
-
-  it('should replace multi-line C-style comments', () => {
-    const input = `
-function example() {
-  /* ... some code ... */
-  console.log('Hello');
-  /* ... rest of the function ... */
-}
-`
-    const expected = `
-function example() {
-  ${EXISTING_CODE_MARKER}
-  console.log('Hello');
-  ${EXISTING_CODE_MARKER}
-}
-`
-    expect(
-      replaceNonStandardPlaceholderComments(input, EXISTING_CODE_MARKER),
-    ).toBe(expected)
-  })
-
-  it('should replace Python-style comments', () => {
-    const input = `
-def example():
-    # ... some code ...
-    print('Hello')
-    # ... rest of the function ...
-`
-    const expected = `
-def example():
-    ${EXISTING_CODE_MARKER}
-    print('Hello')
-    ${EXISTING_CODE_MARKER}
-`
-    expect(
-      replaceNonStandardPlaceholderComments(input, EXISTING_CODE_MARKER),
-    ).toBe(expected)
-  })
-
-  it('should replace JSX comments', () => {
-    const input = `
-function Example() {
-  return (
-    <div>
-      {/* ... existing code ... */}
-      <p>Hello, World!</p>
-      {/* ...rest of component... */}
-    </div>
-  );
-}
-`
-    const expected = `
-function Example() {
-  return (
-    <div>
-      ${EXISTING_CODE_MARKER}
-      <p>Hello, World!</p>
-      ${EXISTING_CODE_MARKER}
-    </div>
-  );
-}
-`
-    expect(
-      replaceNonStandardPlaceholderComments(input, EXISTING_CODE_MARKER),
-    ).toBe(expected)
-  })
-})

common/src/util/string.ts

@@ -45,63 +45,6 @@ export const truncateStringWithMessage = ({
  */
 export const isWhitespace = (character: string) => /\s/.test(character)
 
-export const replaceNonStandardPlaceholderComments = (
-  content: string,
-  replacement: string,
-): string => {
-  const commentPatterns = [
-    // JSX comments (match this first)
-    {
-      regex:
-        /{\s*\/\*\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?\s*\*\/\s*}/gi,
-      placeholder: replacement,
-    },
-    // C-style comments (C, C++, Java, JavaScript, TypeScript, etc.)
-    {
-      regex:
-        /\/\/\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?/gi,
-      placeholder: replacement,
-    },
-    {
-      regex:
-        /\/\*\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?\s*\*\//gi,
-      placeholder: replacement,
-    },
-    // Python, Ruby, R comments
-    {
-      regex:
-        /#\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?/gi,
-      placeholder: replacement,
-    },
-    // HTML-style comments
-    {
-      regex:
-        /<!--\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?\s*-->/gi,
-      placeholder: replacement,
-    },
-    // SQL, Haskell, Lua comments
-    {
-      regex:
-        /--\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?/gi,
-      placeholder: replacement,
-    },
-    // MATLAB comments
-    {
-      regex:
-        /%\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\s*\.{3})?/gi,
-      placeholder: replacement,
-    },
-  ]
-
-  let updatedContent = content
-
-  for (const { regex, placeholder } of commentPatterns) {
-    updatedContent = updatedContent.replaceAll(regex, placeholder)
-  }
-
-  return updatedContent
-}
-
 export const randBoolFromStr = (str: string) => {
   return sumBy(str.split(''), (char) => char.charCodeAt(0)) % 2 === 0
 }
@@ -352,37 +295,6 @@ export const safeReplace = (
   return content.replace(searchStr, escapedReplaceStr)
 }
 
-export const hasLazyEdit = (content: string) => {
-  const cleanedContent = content.toLowerCase().trim()
-  return (
-    cleanedContent.includes('... existing code ...') ||
-    cleanedContent.includes('// rest of the') ||
-    cleanedContent.includes('# rest of the') ||
-    // Match various comment styles with ellipsis and specific words
-    /\/\/\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?/.test(
-      cleanedContent,
-    ) || // C-style single line
-    /\/\*\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?\s*\*\//.test(
-      cleanedContent,
-    ) || // C-style multi-line
-    /#\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?/.test(
-      cleanedContent,
-    ) || // Python/Ruby style
-    /<!--\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?\s*-->/.test(
-      cleanedContent,
-    ) || // HTML style
-    /--\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?/.test(
-      cleanedContent,
-    ) || // SQL/Haskell style
-    /%\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?/.test(
-      cleanedContent,
-    ) || // MATLAB style
-    /{\s*\/\*\s*\.{3}.*(?:rest|unchanged|keep|file|existing|some).*(?:\.{3})?\s*\*\/\s*}/.test(
-      cleanedContent,
-    ) // JSX style
-  )
-}
-
 /**
  * Extracts a JSON field from a string, transforms it, and puts it back.
  * Handles both array and object JSON values.