Replace physical temporary files with a virtual text document provider and standard input streams for diff previews and patch applications

Author: robertpiosik

apps/editor/src/commands/apply-chat-response-command/apply-chat-response-command.ts

@@ -23,6 +23,10 @@ import { ResponseHistoryItem } from '@shared/types/response-history-item'
 import { ApiManager } from '@/services/api-manager'
 import { parse_response } from './utils/clipboard-parser/clipboard-parser'
 import { t } from '@/i18n'
+import {
+  preview_document_provider,
+  CwcPreviewProvider
+} from './utils/preview/virtual-document-provider'
 
 let in_progress = false
 let placeholder_created_at_for_update: number | undefined
@@ -44,6 +48,13 @@ export const apply_chat_response_command = (params: {
   workspace_provider: WorkspaceProvider
   api_manager: ApiManager
 }) => {
+  params.context.subscriptions.push(
+    vscode.workspace.registerTextDocumentContentProvider(
+      CwcPreviewProvider.scheme,
+      preview_document_provider
+    )
+  )
+
   return vscode.commands.registerCommand(
     'codeWebChat.applyChatResponse',
     async (args?: CommandArgs) => {

apps/editor/src/commands/apply-chat-response-command/handlers/diff-handler.ts

@@ -3,14 +3,11 @@ import * as path from 'path'
 import * as fs from 'fs'
 import { exec } from 'child_process'
 import { Logger } from '@shared/utils/logger'
-import { promisify } from 'util'
 import { OriginalFileState } from '../types/original-file-state'
 import { create_safe_path } from '@/utils/path-sanitizer'
 import { apply_diff } from '../utils/edit-formats/diffs'
 import { remove_directory_if_empty } from '../utils/file-operations'
 
-const execAsync = promisify(exec)
-
 const INDENTATION_BASED_EXTENSIONS = new Set(['.py', '.yaml', '.yml'])
 
 const is_indentation_based_file = (file_path: string): boolean => {
@@ -398,17 +395,34 @@ const handle_deleted_file_patch = async (
   }
 }
 
+const run_git_apply = (
+  patch: string,
+  cwd: string,
+  flags: string
+): Promise<void> => {
+  return new Promise((resolve, reject) => {
+    const child = exec(`git apply ${flags} -`, { cwd }, (error) => {
+      if (error) {
+        reject(error)
+      } else {
+        resolve()
+      }
+    })
+    child.stdin?.write(patch)
+    child.stdin?.end()
+  })
+}
+
 const process_diff = async (params: {
   file_path: string
-  diff_patch_path: string
+  diff_patch_content: string
   use_strict_whitespace?: boolean
 }): Promise<string> => {
   const file_content = fs.readFileSync(params.file_path, 'utf8')
-  const diff_patch_content = fs.readFileSync(params.diff_patch_path, 'utf8')
 
   const result = apply_diff({
     original_code: file_content,
-    diff_patch: diff_patch_content,
+    diff_patch: params.diff_patch_content,
     use_strict_whitespace: params.use_strict_whitespace
   })
 
@@ -447,7 +461,6 @@ export const apply_git_patch = async (
   }
 
   let closed_files: vscode.Uri[] = []
-  const temp_file = path.join(workspace_path, '.tmp_patch')
   let original_states: OriginalFileState[] | undefined
 
   try {
@@ -462,16 +475,6 @@ export const apply_git_patch = async (
       workspace_path
     )
 
-    // Write patch file and ensure it's synced to disk before git apply reads it
-    const patch_buffer = Buffer.from(patch_content)
-    const fd = await fs.promises.open(temp_file, 'w')
-    try {
-      await fd.write(patch_buffer)
-      await fd.sync() // Ensure data is flushed to disk
-    } finally {
-      await fd.close()
-    }
-
     let last_error: any = null
     let success = false
     let diff_application_method: 'recount' | 'search_and_replace' | undefined =
@@ -497,9 +500,7 @@ export const apply_git_patch = async (
           .filter(Boolean)
           .join(' ')
 
-        await execAsync(`git apply ${flags} "${temp_file}"`, {
-          cwd: workspace_path
-        })
+        await run_git_apply(patch_content, workspace_path, flags)
         success = true
         diff_application_method = 'recount'
         Logger.info({
@@ -527,7 +528,7 @@ export const apply_git_patch = async (
 
         applied_content = await process_diff({
           file_path: file_path_safe,
-          diff_patch_path: temp_file,
+          diff_patch_content: patch_content,
           use_strict_whitespace
         })
         success = true
@@ -544,7 +545,6 @@ export const apply_git_patch = async (
     if (success) {
       await process_modified_files(file_paths, workspace_path)
       await reopen_closed_files(closed_files)
-      await vscode.workspace.fs.delete(vscode.Uri.file(temp_file))
 
       if (original_states) {
         for (const state of original_states) {
@@ -592,18 +592,6 @@ export const apply_git_patch = async (
     // This outer catch handles setup errors and final application failures
     await reopen_closed_files(closed_files)
 
-    try {
-      if (fs.existsSync(temp_file)) {
-        await vscode.workspace.fs.delete(vscode.Uri.file(temp_file))
-      }
-    } catch (deleteError) {
-      Logger.warn({
-        function_name: 'apply_git_patch',
-        message: 'Failed to delete temp patch file in error handler.',
-        data: deleteError
-      })
-    }
-
     const has_rejects = error?.message?.includes('.rej')
     if (has_rejects) {
       const file_paths = extract_file_paths_from_patch(patch_content)

apps/editor/src/commands/apply-chat-response-command/utils/preview/file-preparer.ts

@@ -1,8 +1,7 @@
 import * as fs from 'fs'
 import * as crypto from 'crypto'
-import * as path from 'path'
-import * as os from 'os'
 import { OriginalFileState } from '@/commands/apply-chat-response-command/types/original-file-state'
+import * as vscode from 'vscode'
 import { create_safe_path } from '@/utils/path-sanitizer'
 import { get_diff_stats } from './diff-utils'
 import { PreparedFile, PreviewableFile } from './types'
@@ -52,8 +51,9 @@ export const prepare_files_from_original_states = async (params: {
       .createHash('md5')
       .update(sanitized_file_path)
       .digest('hex')
-    const temp_filename = `cwc-${hash}.tmp`
-    const temp_file_path = path.join(os.tmpdir(), temp_filename)
+    const original_uri = vscode.Uri.file(sanitized_file_path)
+      .with({ scheme: 'cwc-preview', query: `hash=${hash}` })
+      .toString()
 
     const original_content_for_diff = state.file_path_to_restore
       ? ''
@@ -93,7 +93,7 @@ export const prepare_files_from_original_states = async (params: {
       previewable_file,
       sanitized_path: sanitized_file_path,
       original_content: original_content_for_diff,
-      temp_file_path,
+      original_uri,
       file_exists: state.file_state != 'new'
     })
 
@@ -112,11 +112,11 @@ export const prepare_files_from_original_states = async (params: {
         .createHash('md5')
         .update(restored_sanitized_file_path)
         .digest('hex')
-      const restored_temp_filename = `cwc-${restored_hash}.tmp`
-      const restored_temp_file_path = path.join(
-        os.tmpdir(),
-        restored_temp_filename
+      const restored_original_uri = vscode.Uri.file(
+        restored_sanitized_file_path
       )
+        .with({ scheme: 'cwc-preview', query: `hash=${restored_hash}` })
+        .toString()
 
       const restored_diff_stats = get_diff_stats({
         original_content: state.content,
@@ -139,7 +139,7 @@ export const prepare_files_from_original_states = async (params: {
         previewable_file: restored_previewable_file,
         sanitized_path: restored_sanitized_file_path,
         original_content: state.content,
-        temp_file_path: restored_temp_file_path,
+        original_uri: restored_original_uri,
         file_exists: false
       })
     }

apps/editor/src/commands/apply-chat-response-command/utils/preview/preview.ts

@@ -231,16 +231,16 @@ export const preview = async (params: {
           | { file_path: string; position: vscode.Position }
           | undefined
 
-        if (result.active_file_path && result.active_position) {
-          const active_path = result.active_file_path
+        if (result.active_file_uri && result.active_position) {
+          const active_uri = result.active_file_uri
           const matching_prepared = prepared_files.find(
-            (pf) => pf.temp_file_path === active_path
+            (pf) => pf.original_uri === active_uri
           )
 
           active_editor_state = {
             file_path: matching_prepared
               ? matching_prepared.sanitized_path
-              : active_path,
+              : vscode.Uri.parse(active_uri).fsPath,
             position: result.active_position
           }
         }

apps/editor/src/commands/apply-chat-response-command/utils/preview/temp-file-manager.ts

@@ -1,18 +1,20 @@
-import * as fs from 'fs'
 import { PreparedFile } from './types'
+import * as vscode from 'vscode'
+import { preview_document_provider } from './virtual-document-provider'
 
 export const create_temp_files_with_original_content = (
   prepared_files: PreparedFile[]
 ) => {
   prepared_files.forEach((file) => {
-    fs.writeFileSync(file.temp_file_path, file.original_content)
+    preview_document_provider.setContent(
+      vscode.Uri.parse(file.original_uri),
+      file.original_content
+    )
   })
 }
 
 export const cleanup_temp_files = (prepared_files: PreparedFile[]) => {
   prepared_files.forEach((file) => {
-    try {
-      fs.unlinkSync(file.temp_file_path)
-    } catch (e) {}
+    preview_document_provider.deleteContent(vscode.Uri.parse(file.original_uri))
   })
 }

apps/editor/src/commands/apply-chat-response-command/utils/preview/types.ts

@@ -8,8 +8,8 @@ export type PreviewDecision =
 export type PreviewResult = {
   decision: PreviewDecision
   new_content: string
-  temp_file_path: string
-  active_file_path?: string
+  original_uri: string
+  active_file_uri?: string
   active_position?: vscode.Position
 }
 
@@ -21,7 +21,7 @@ export type PreparedFile = {
   previewable_file: PreviewableFile
   sanitized_path: string
   original_content: string
-  temp_file_path: string
+  original_uri: string
   file_exists: boolean
   content_to_restore?: string
 }

apps/editor/src/commands/apply-chat-response-command/utils/preview/virtual-document-provider.ts

@@ -0,0 +1,23 @@
+import * as vscode from 'vscode'
+
+export class CwcPreviewProvider implements vscode.TextDocumentContentProvider {
+  static scheme = 'cwc-preview'
+  private contents = new Map<string, string>()
+  private onDidChangeEmitter = new vscode.EventEmitter<vscode.Uri>()
+  onDidChange = this.onDidChangeEmitter.event
+
+  provideTextDocumentContent(uri: vscode.Uri): string {
+    return this.contents.get(uri.toString()) || ''
+  }
+
+  setContent(uri: vscode.Uri, content: string) {
+    this.contents.set(uri.toString(), content)
+    this.onDidChangeEmitter.fire(uri)
+  }
+
+  deleteContent(uri: vscode.Uri) {
+    this.contents.delete(uri.toString())
+  }
+}
+
+export const preview_document_provider = new CwcPreviewProvider()

apps/editor/src/commands/apply-chat-response-command/utils/preview/vscode-ui.ts

@@ -10,7 +10,7 @@ export const close_preview_diff_editors = async (
   prepared_files: PreparedFile[]
 ): Promise<void> => {
   const temp_uris = new Set(
-    prepared_files.map((f) => vscode.Uri.file(f.temp_file_path).toString())
+    prepared_files.map((f) => vscode.Uri.parse(f.original_uri).toString())
   )
   const promises: Thenable<boolean>[] = []
 
@@ -31,7 +31,7 @@ export const close_preview_diff_editors = async (
 export const show_diff_with_actions = async (
   prepared_file: PreparedFile
 ): Promise<PreviewResult> => {
-  const left_doc_uri = vscode.Uri.file(prepared_file.temp_file_path)
+  const left_doc_uri = vscode.Uri.parse(prepared_file.original_uri)
   const right_doc_uri = vscode.Uri.file(prepared_file.sanitized_path)
 
   const title = path.basename(prepared_file.previewable_file.file_path)
@@ -57,19 +57,19 @@ export const show_diff_with_actions = async (
       } catch (error) {}
 
       const active_editor = vscode.window.activeTextEditor
-      let active_file_path: string | undefined
+      let active_file_uri: string | undefined
       let active_position: vscode.Position | undefined
 
       if (active_editor) {
-        active_file_path = active_editor.document.uri.fsPath
+        active_file_uri = active_editor.document.uri.toString()
         active_position = active_editor.selection.active
       }
 
       resolve({
         decision,
         new_content: final_content,
-        temp_file_path: prepared_file.temp_file_path,
-        active_file_path,
+        original_uri: prepared_file.original_uri,
+        active_file_uri,
         active_position
       })
     }