devutils-mcp-server

Instructions

Implementation Reference

• src/tools/text.ts:274-311 (handler)

  The implementation of the text_diff tool, including its schema definition and the logic to compare two texts and produce a line-by-line diff.

  server.tool(
    "text_diff",
    "Compare two strings and show a simple line-by-line diff. Lines prefixed with '+' are additions, '-' are deletions, ' ' are unchanged.",
    {
      text1: z.string().describe("First text (original)"),
      text2: z.string().describe("Second text (modified)"),
    },
    async ({ text1, text2 }) => {
      const lines1 = text1.split("\n");
      const lines2 = text2.split("\n");
      const maxLen = Math.max(lines1.length, lines2.length);
      const diffLines: string[] = [];
  
      for (let i = 0; i < maxLen; i++) {
        const l1 = i < lines1.length ? lines1[i] : undefined;
        const l2 = i < lines2.length ? lines2[i] : undefined;
  
        if (l1 === l2) {
          diffLines.push(`  ${l1}`);
        } else {
          if (l1 !== undefined) diffLines.push(`- ${l1}`);
          if (l2 !== undefined) diffLines.push(`+ ${l2}`);
        }
      }
  
      const summary = {
        lines_in_original: lines1.length,
        lines_in_modified: lines2.length,
        additions: diffLines.filter((l) => l.startsWith("+ ")).length,
        deletions: diffLines.filter((l) => l.startsWith("- ")).length,
        unchanged: diffLines.filter((l) => l.startsWith("  ")).length,
      };
  
      const output = `${JSON.stringify(summary, null, 2)}\n\n--- Diff ---\n${diffLines.join("\n")}`;
  
      return { content: [{ type: "text" as const, text: output }] };
    }
  );