/**
* Low-level DAP test for vscode-js-debug
*
* NOTE: vscode-js-debug uses a multi-session DAP architecture that requires
* handling 'startDebugging' reverse requests. This test documents the current
* state of JavaScript debugging support.
*
* For full functionality, a session multiplexer is needed (similar to nvim-dap-vscode-js).
* See: https://github.com/microsoft/vscode-js-debug/issues/969
*/
import { DapClient, DapClientConfig } from '../src/dap/dap-client.js';
import * as path from 'path';
const SOURCE_PATH = path.resolve(
import.meta.dirname,
'fixtures/js_test/sample.js'
);
async function sleep(ms: number): Promise<void> {
return new Promise(resolve => setTimeout(resolve, ms));
}
async function main() {
console.log('=== Low-Level vscode-js-debug Test ===\n');
console.log('Source:', SOURCE_PATH);
console.log('\nNOTE: vscode-js-debug requires multi-session DAP support.');
console.log('This test shows the current state of JavaScript debugging.\n');
const serverPath = path.join(
process.env.HOME || '~',
'.mcp-debugger/adapters/js-debug/js-debug/src/dapDebugServer.js'
);
console.log('Server:', serverPath);
const config: DapClientConfig = {
command: 'node',
args: [serverPath, '0'],
mode: 'tcp',
timeout: 30000
};
const client = new DapClient(config);
// Listen to all events
client.on('event', (event) => {
console.log('<<< event:', event.event);
});
client.on('output', (event) => {
const output = event.body.output?.trim();
if (output && output.startsWith('[Child Session]')) {
console.log(' ', output);
}
});
client.on('stopped', (event) => {
console.log('<<< STOPPED:', event.body.reason, 'threadId:', event.body.threadId);
});
client.on('error', (err) => {
console.error('Client error:', err.message);
});
try {
// Start the adapter
console.log('\n1. Starting vscode-js-debug adapter...');
await client.start();
console.log(' Adapter started and connected');
// Initialize
console.log('\n2. Initialize...');
const initResponse = await client.initialize({
clientID: 'mcp-debugger-test',
clientName: 'MCP Debugger Test',
adapterID: 'pwa-node',
linesStartAt1: true,
columnsStartAt1: true,
pathFormat: 'path',
supportsVariableType: true,
supportsVariablePaging: true,
supportsRunInTerminalRequest: false,
supportsStartDebuggingRequest: true, // We support this now
locale: 'en-US'
});
console.log(' Capabilities:', Object.keys(initResponse || {}).length, 'keys');
await sleep(500);
// Set breakpoint
console.log('\n3. Set breakpoint at line 12...');
const bpResult = await client.setBreakpoints(
{ path: SOURCE_PATH },
[{ line: 12 }]
);
console.log(' Breakpoint:', bpResult[0]?.verified ? 'verified' : 'provisional');
// Launch
console.log('\n4. Launch...');
const launchConfig = {
type: 'pwa-node',
request: 'launch',
name: 'MCP Debug Node.js',
program: SOURCE_PATH,
cwd: path.dirname(SOURCE_PATH),
stopOnEntry: true,
console: 'internalConsole',
skipFiles: ['<node_internals>/**'],
trace: true // Enable trace logging
};
client.launchAsync(launchConfig);
console.log(' Launch request sent');
// Configuration done
console.log('\n5. Configuration done...');
await client.configurationDone();
console.log(' ConfigurationDone sent');
// Wait for stopped event
console.log('\n6. Waiting for stopped event (10 seconds for child session setup)...');
let stoppedThreadId: number | null = null;
const stoppedPromise = new Promise<number>((resolve) => {
const handler = (event: { body: { threadId?: number } }) => {
console.log(' Got stopped event!');
stoppedThreadId = event.body.threadId ?? 0;
client.off('stopped', handler);
resolve(stoppedThreadId);
};
client.on('stopped', handler);
// Timeout fallback
setTimeout(() => resolve(-1), 10000);
});
const threadId = await stoppedPromise;
if (threadId === -1) {
console.log(' ⚠️ Timeout waiting for stopped event');
} else {
console.log(' ✓ Stopped at threadId:', threadId);
}
// Get threads
console.log('\n7. Get threads...');
const threads = await client.threads();
console.log(' Threads:', threads.length);
for (const t of threads) {
console.log(' -', t.id, t.name);
}
if (threads.length === 0) {
console.log(' ⚠️ No threads available - checking if child session is active...');
console.log(' hasActiveChildSession:', client.hasActiveChildSession());
}
// Try to get stack trace if we have a thread
if (threads.length > 0 || threadId >= 0) {
const tid = threads.length > 0 ? threads[0].id : threadId;
console.log('\n8. Get stack trace for thread', tid, '...');
try {
const stack = await client.stackTrace(tid);
console.log(' Stack frames:', stack.length);
for (const frame of stack.slice(0, 3)) {
console.log(' -', frame.name, '@', frame.source?.path ?? 'unknown', ':', frame.line);
}
// Get variables if we have a frame
if (stack.length > 0) {
console.log('\n9. Get scopes for frame', stack[0].id, '...');
const scopes = await client.scopes(stack[0].id);
console.log(' Scopes:', scopes.length);
for (const scope of scopes) {
console.log(' -', scope.name, '(ref:', scope.variablesReference, ')');
}
// Get variables from first scope
if (scopes.length > 0 && scopes[0].variablesReference > 0) {
console.log('\n10. Get variables from', scopes[0].name, '...');
const vars = await client.variables(scopes[0].variablesReference);
console.log(' Variables:', vars.length);
for (const v of vars.slice(0, 5)) {
console.log(' -', v.name, '=', v.value);
}
}
}
} catch (error) {
console.log(' Error getting stack:', error);
}
}
// Disconnect
console.log('\n11. Disconnect...');
await client.disconnect();
} catch (error) {
console.error('\nError:', error);
}
await sleep(500);
console.log('\n=== Test Complete ===');
console.log('\nSummary: vscode-js-debug multi-session DAP debugging test completed.');
process.exit(0);
}
main();
