SvelteLS.MCP

Instructions

Implementation Reference

• src/tools/editing.ts:98-153 (handler)

  The handler function for the `format_document` tool, which manages the LSP request for document formatting or range formatting and applies the resulting text edits.

  async ({
    filePath,
    startLine,
    endLine,
    tabSize,
    insertSpaces,
  }): Promise<ToolResult> => {
    try {
      const prep = await prepareDocumentRequest(lsp, filePath);
      if ("error" in prep) return textResult(prep.error);
  
      const options = {
        tabSize,
        insertSpaces,
        trimTrailingWhitespace: true,
        insertFinalNewline: true,
        trimFinalNewlines: true,
      };
  
      let result: any;
      if (startLine != null) {
        const sl = startLine - 1;
        const el = (endLine ?? startLine) - 1;
        result = await lsp.request("textDocument/rangeFormatting", {
          textDocument: { uri: prep.uri },
          range: {
            start: { line: sl, character: 0 },
            end: { line: el + 1, character: 0 },
          },
          options,
        });
      } else {
        result = await lsp.request("textDocument/formatting", {
          textDocument: { uri: prep.uri },
          options,
        });
      }
  
      if (!Array.isArray(result) || result.length === 0) {
        return textResult(
          `No formatting changes needed in ${basename(filePath)}.`
        );
      }
  
      const count = await applyTextEdits(lsp, filePath, result);
      const rangeDesc =
        startLine != null
          ? ` (lines ${startLine}-${endLine ?? startLine})`
          : "";
      return textResult(
        `Formatted ${basename(filePath)}${rangeDesc}: ${count} edit(s) applied.`
      );
    } catch (ex) {
      return textResult(formatError(ex));
    }
  }

• src/tools/editing.ts:75-97 (registration)

  Tool registration for `format_document` including title, description, and input schema.

  server.registerTool(
    "format_document",
    {
      title: "Format Document",
      description:
        "Format a file (or a range of lines) using the project's formatting rules.",
      inputSchema: z.object({
        filePath: z.string().describe("Absolute path to the file"),
        startLine: z
          .number()
          .optional()
          .describe("Optional start line (1-based) for range formatting"),
        endLine: z
          .number()
          .optional()
          .describe("Optional end line (1-based) for range formatting"),
        tabSize: z.number().default(2).describe("Tab size. Default: 2"),
        insertSpaces: z
          .boolean()
          .default(true)
          .describe("Use spaces instead of tabs. Default: true"),
      }),
    },