delete_from_file

Instructions

Implementation Reference

• tools/fileEditorTool.ts:130-194 (handler)

  The primary handler function implementing the deletion logic for various selector types: exact text string, line range {startLine, endLine}, or between start/end markers.

  static async deleteFromFile(
      filePath: string, 
      selector: string | {startLine: number, endLine?: number} | {start: string, end: string}, 
      dryRun: boolean = false
  ): Promise<string> {
      try {
          // 檢查檔案是否存在
          if (!existsSync(filePath)) {
              return `錯誤: 檔案 ${filePath} 不存在`;
          }
  
          // 讀取檔案內容
          let fileContent = await fs.readFile(filePath, 'utf8');
          let originalContent = fileContent;
          
          // 根據不同的選擇器類型處理刪除操作
          if (typeof selector === 'string') {
              // 刪除特定文字
              if (!fileContent.includes(selector)) {
                  return `錯誤: 在檔案中找不到文字「${selector}」`;
              }
              
              fileContent = fileContent.replace(selector, '');
          } else if ('startLine' in selector) {
              // 刪除行範圍
              const lines = fileContent.split(/\r?\n/);
              const startLine = selector.startLine;
              const endLine = selector.endLine || startLine;
              
              if (startLine < 1 || startLine > lines.length || endLine < startLine || endLine > lines.length) {
                  return `錯誤: 行範圍 ${startLine}-${endLine} 超出檔案範圍 (1-${lines.length})`;
              }
              
              // 刪除指定行範圍
              lines.splice(startLine - 1, endLine - startLine + 1);
              fileContent = lines.join('\n');
          } else if ('start' in selector && 'end' in selector) {
              // 刪除兩個標記之間的內容
              const startPos = fileContent.indexOf(selector.start);
              const endPos = fileContent.indexOf(selector.end, startPos + selector.start.length);
              
              if (startPos === -1 || endPos === -1) {
                  return `錯誤: 在檔案中找不到指定的標記範圍`;
              }
              
              // 刪除開始標記到結束標記之間的內容（包括標記）
              const beforeStart = fileContent.substring(0, startPos);
              const afterEnd = fileContent.substring(endPos + selector.end.length);
              fileContent = beforeStart + afterEnd;
          }
          
          // 如果是預覽模式，生成差異報告
          if (dryRun) {
              return this.generateDiff(originalContent, fileContent, filePath);
          }
          
          // 寫入檔案
          await fs.writeFile(filePath, fileContent, 'utf8');
          
          return `內容已成功從檔案刪除: ${filePath}`;
      } catch (error) {
          console.error(`刪除內容時發生錯誤: ${error}`);
          return `刪除內容時發生錯誤: ${error instanceof Error ? error.message : '未知錯誤'}`;
      }
  }

• main.ts:273-287 (schema)

  Zod schema defining the input parameters for the delete_from_file tool: path, selector (union of string, line range object, or marker range object), and dryRun flag.

  {
      path: z.string(),
      selector: z.union([
          z.string().describe("要刪除的確切文字"),
          z.object({
              startLine: z.number().describe("開始行號 (從1開始)"),
              endLine: z.number().optional().describe("結束行號，如果省略則只刪除單行")
          }),
          z.object({
              start: z.string().describe("開始標記文字"),
              end: z.string().describe("結束標記文字")
          })
      ]),
      dryRun: z.boolean().default(false).describe("預覽變更而不實際修改檔案")
  },

• main.ts:271-300 (registration)

  MCP server tool registration for 'delete_from_file', including description, input schema, and thin async handler that delegates to FileEditorTool.deleteFromFile and formats the response.

  server.tool("delete_from_file",
      "從檔案中刪除特定內容",
      {
          path: z.string(),
          selector: z.union([
              z.string().describe("要刪除的確切文字"),
              z.object({
                  startLine: z.number().describe("開始行號 (從1開始)"),
                  endLine: z.number().optional().describe("結束行號，如果省略則只刪除單行")
              }),
              z.object({
                  start: z.string().describe("開始標記文字"),
                  end: z.string().describe("結束標記文字")
              })
          ]),
          dryRun: z.boolean().default(false).describe("預覽變更而不實際修改檔案")
      },
      async ({ path, selector, dryRun = false }) => {
          try {
              const result = await FileEditorTool.deleteFromFile(path, selector, dryRun);
              return {
                  content: [{ type: "text", text: result }]
              };
          } catch (error) {
              return {
                  content: [{ type: "text", text: `刪除內容失敗: ${error instanceof Error ? error.message : "未知錯誤"}` }]
              };
          }
      }
  );