feat: add append_to_file tool for appending content to files (#2712)

- Implemented the append_to_file tool to allow users to append content to existing files or create new ones if they do not exist.
- Updated the rules and instructions to include the new tool.
- Added tests for the append_to_file functionality, covering various scenarios including error handling and content preprocessing.
- Enhanced the experiment schema to include the new append_to_file experiment ID.
- Updated relevant interfaces and types to accommodate the new tool.
- Modified the UI to display the append_to_file tool in the appropriate sections.

Author: samhvw8

src/core/Cline.ts

@@ -79,6 +79,7 @@ import { askFollowupQuestionTool } from "./tools/askFollowupQuestionTool"
 import { switchModeTool } from "./tools/switchModeTool"
 import { attemptCompletionTool } from "./tools/attemptCompletionTool"
 import { newTaskTool } from "./tools/newTaskTool"
+import { appendToFileTool } from "./tools/appendToFileTool"
 
 // prompts
 import { formatResponse } from "./prompts/responses"
@@ -1406,6 +1407,8 @@ export class Cline extends EventEmitter<ClineEvents> {
 							return `[${block.name} for '${block.params.task}']`
 						case "write_to_file":
 							return `[${block.name} for '${block.params.path}']`
+						case "append_to_file":
+							return `[${block.name} for '${block.params.path}']`
 						case "apply_diff":
 							return `[${block.name} for '${block.params.path}']`
 						case "search_files":
@@ -1589,6 +1592,9 @@ export class Cline extends EventEmitter<ClineEvents> {
 					case "write_to_file":
 						await writeToFileTool(this, block, askApproval, handleError, pushToolResult, removeClosingTag)
 						break
+					case "append_to_file":
+						await appendToFileTool(this, block, askApproval, handleError, pushToolResult, removeClosingTag)
+						break
 					case "apply_diff":
 						await applyDiffTool(this, block, askApproval, handleError, pushToolResult, removeClosingTag)
 						break

src/core/prompts/__tests__/__snapshots__/system.test.ts.snap

@@ -16,6 +16,9 @@ function getEditingInstructions(diffStrategy?: DiffStrategy, experiments?: Recor
 	if (experiments?.["insert_content"]) {
 		availableTools.push("insert_content (for adding lines to existing files)")
 	}
+	if (experiments?.["append_to_file"]) {
+		availableTools.push("append_to_file (for appending content to the end of files)")
+	}
 	if (experiments?.["search_and_replace"]) {
 		availableTools.push("search_and_replace (for finding and replacing individual pieces of text)")
 	}
@@ -32,6 +35,12 @@ function getEditingInstructions(diffStrategy?: DiffStrategy, experiments?: Recor
 		)
 	}
 
+	if (experiments?.["append_to_file"]) {
+		instructions.push(
+			"- The append_to_file tool adds content to the end of files, such as appending new log entries or adding new data records. This tool will always add the content at the end of the file.",
+		)
+	}
+
 	if (experiments?.["search_and_replace"]) {
 		instructions.push(
 			"- The search_and_replace tool finds and replaces text or regex in files. This tool allows you to search for a specific regex pattern or text and replace it with another value. Be cautious when using this tool to ensure you are replacing the correct text. It can support multiple operations at once.",

src/core/prompts/sections/rules.ts

@@ -0,0 +1,25 @@
+import { ToolArgs } from "./types"
+
+export function getAppendToFileDescription(args: ToolArgs): string {
+	return `## append_to_file
+Description: Request to append content to a file at the specified path. If the file exists, the content will be appended to the end of the file. If the file doesn't exist, it will be created with the provided content. This tool will automatically create any directories needed to write the file.
+Parameters:
+- path: (required) The path of the file to append to (relative to the current workspace directory ${args.cwd})
+- content: (required) The content to append to the file. The content will be added at the end of the existing file content. Do NOT include line numbers in the content.
+Usage:
+<append_to_file>
+<path>File path here</path>
+<content>
+Your content to append here
+</content>
+</append_to_file>
+
+Example: Requesting to append to a log file
+<append_to_file>
+<path>logs/app.log</path>
+<content>
+[2024-04-17 15:20:30] New log entry
+[2024-04-17 15:20:31] Another log entry
+</content>
+</append_to_file>`
+}

src/core/prompts/tools/append-to-file.ts

@@ -2,6 +2,7 @@ import { getExecuteCommandDescription } from "./execute-command"
 import { getReadFileDescription } from "./read-file"
 import { getFetchInstructionsDescription } from "./fetch-instructions"
 import { getWriteToFileDescription } from "./write-to-file"
+import { getAppendToFileDescription } from "./append-to-file"
 import { getSearchFilesDescription } from "./search-files"
 import { getListFilesDescription } from "./list-files"
 import { getInsertContentDescription } from "./insert-content"
@@ -26,6 +27,7 @@ const toolDescriptionMap: Record<string, (args: ToolArgs) => string | undefined>
 	read_file: (args) => getReadFileDescription(args),
 	fetch_instructions: () => getFetchInstructionsDescription(),
 	write_to_file: (args) => getWriteToFileDescription(args),
+	append_to_file: (args) => getAppendToFileDescription(args),
 	search_files: (args) => getSearchFilesDescription(args),
 	list_files: (args) => getListFilesDescription(args),
 	list_code_definition_names: (args) => getListCodeDefinitionNamesDescription(args),
@@ -101,6 +103,7 @@ export {
 	getReadFileDescription,
 	getFetchInstructionsDescription,
 	getWriteToFileDescription,
+	getAppendToFileDescription,
 	getSearchFilesDescription,
 	getListFilesDescription,
 	getListCodeDefinitionNamesDescription,