get_location

Instructions

Implementation Reference

• src/mcp-server.js:1009-1082 (registration)

  Tool registration for 'get_location' on line 1010 using server.tool(), with empty schema on line 1013.

  // Get current location tool
  server.tool(
    "get_location",
    "Gets the current execution location when paused",
    {},
    async () => {
      try {
        // Ensure debugger is enabled
        if (!inspector.debuggerEnabled) {
          await inspector.enableDebugger();
        }
        
        if (!inspector.paused || inspector.currentCallFrames.length === 0) {
          return {
            content: [{
              type: "text",
              text: "Debugger is not paused at a breakpoint"
            }]
          };
        }
        
        const frame = inspector.currentCallFrames[0];
        const { url, lineNumber, columnNumber } = frame.location;
        
        // Get call stack
        const callstack = inspector.currentCallFrames.map(frame => {
          return {
            functionName: frame.functionName || '(anonymous)',
            url: frame.url,
            lineNumber: frame.location.lineNumber + 1,
            columnNumber: frame.location.columnNumber
          };
        });
        
        // Get source code for context
        let sourceContext = '';
        try {
          const scriptSource = await inspector.getScriptSource(frame.location.scriptId);
          if (scriptSource) {
            const lines = scriptSource.split('\n');
            const startLine = Math.max(0, lineNumber - 3);
            const endLine = Math.min(lines.length - 1, lineNumber + 3);
            
            for (let i = startLine; i <= endLine; i++) {
              const prefix = i === lineNumber ? '> ' : '  ';
              sourceContext += `${prefix}${i + 1}: ${lines[i]}\n`;
            }
          }
        } catch (err) {
          sourceContext = 'Unable to retrieve source code';
        }
        
        return {
          content: [{
            type: "text",
            text: JSON.stringify({
              url,
              lineNumber: lineNumber + 1,
              columnNumber,
              callstack,
              sourceContext
            }, null, 2)
          }]
        };
      } catch (err) {
        return {
          content: [{
            type: "text",
            text: `Error getting location: ${err.message}`
          }]
        };
      }
    }
  );

• src/mcp-server.js:1014-1081 (handler)

  Handler function that gets current execution location when paused - reads call frame location, builds callstack, retrieves source context, and returns JSON with url, lineNumber, columnNumber, callstack, and sourceContext.

  async () => {
    try {
      // Ensure debugger is enabled
      if (!inspector.debuggerEnabled) {
        await inspector.enableDebugger();
      }
      
      if (!inspector.paused || inspector.currentCallFrames.length === 0) {
        return {
          content: [{
            type: "text",
            text: "Debugger is not paused at a breakpoint"
          }]
        };
      }
      
      const frame = inspector.currentCallFrames[0];
      const { url, lineNumber, columnNumber } = frame.location;
      
      // Get call stack
      const callstack = inspector.currentCallFrames.map(frame => {
        return {
          functionName: frame.functionName || '(anonymous)',
          url: frame.url,
          lineNumber: frame.location.lineNumber + 1,
          columnNumber: frame.location.columnNumber
        };
      });
      
      // Get source code for context
      let sourceContext = '';
      try {
        const scriptSource = await inspector.getScriptSource(frame.location.scriptId);
        if (scriptSource) {
          const lines = scriptSource.split('\n');
          const startLine = Math.max(0, lineNumber - 3);
          const endLine = Math.min(lines.length - 1, lineNumber + 3);
          
          for (let i = startLine; i <= endLine; i++) {
            const prefix = i === lineNumber ? '> ' : '  ';
            sourceContext += `${prefix}${i + 1}: ${lines[i]}\n`;
          }
        }
      } catch (err) {
        sourceContext = 'Unable to retrieve source code';
      }
      
      return {
        content: [{
          type: "text",
          text: JSON.stringify({
            url,
            lineNumber: lineNumber + 1,
            columnNumber,
            callstack,
            sourceContext
          }, null, 2)
        }]
      };
    } catch (err) {
      return {
        content: [{
          type: "text",
          text: `Error getting location: ${err.message}`
        }]
      };
    }
  }

• src/mcp-server.js:1013-1013 (schema)

  Empty schema object (no parameters) for the get_location tool.

  {},