feat: Connect debug client

Author: Jan Krems

lib/internal/inspect-protocol.js

@@ -20,6 +20,7 @@
  * IN THE SOFTWARE.
  */
 'use strict';
+const crypto = require('crypto');
 const { EventEmitter } = require('events');
 const http = require('http');
 const util = require('util');
@@ -271,8 +272,14 @@ class Client extends EventEmitter {
         this.emit('error', error);
       });
     };
-    httpReq.on('upgrade', handshakeListener);
-    httpReq.end();
+
+    return new Promise((resolve, reject) => {
+      this.once('error', reject);
+      this.once('ready', resolve);
+
+      httpReq.on('upgrade', handshakeListener);
+      httpReq.end();
+    });
   }
 }
 module.exports = Client;

lib/node-inspect.js

@@ -31,14 +31,32 @@ function throwUnexpectedError(error) {
   process.nextTick(() => { throw error; });
 }
 
-function runScript(script, scriptArgs, inspectPort) {
+function delay(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+function runScript(script, scriptArgs, inspectPort, childPrint) {
   return new Promise((resolve) => {
     const args = [
       '--inspect',
       `--debug-brk=${inspectPort}`,
     ].concat([script], scriptArgs);
     const child = spawn(process.execPath, args);
-    resolve(child);
+    child.stdout.setEncoding('utf8');
+    child.stderr.setEncoding('utf8');
+    child.stdout.on('data', childPrint);
+    child.stderr.on('data', childPrint);
+
+    let output = '';
+    function waitForListenHint(text) {
+      output += text;
+      if (/chrome-devtools:\/\//.test(output)) {
+        child.stderr.removeListener('data', waitForListenHint);
+        resolve(child);
+      }
+    }
+
+    child.stderr.on('data', waitForListenHint);
   });
 }
 
@@ -48,12 +66,15 @@ class NodeInspector {
     this.stdin = stdin;
     this.stdout = stdout;
 
-    this.paused = false;
+    this.paused = true;
     this.child = null;
 
     this._runScript = options.script ?
-      runScript.bind(null, options.script, options.scriptArgs, options.port) :
-      Promise.resolve.bind(null, null);
+      runScript.bind(null,
+        options.script, options.scriptArgs,
+        options.port,
+        this.childPrint.bind(this)
+      ) : () => Promise.resolve(null);
 
     this.client = new ProtocolClient(options.port, options.host);
 
@@ -82,6 +103,7 @@ class NodeInspector {
     this.repl.on('exit', () => {
       process.exit(0);
     });
+    this.paused = false;
   }
 
   killChild() {
@@ -96,12 +118,29 @@ class NodeInspector {
     this.killChild();
     return this._runScript().then((child) => {
       this.child = child;
-      this.child.stdout.on('data', text => this.childPrint(text));
-      this.child.stderr.on('data', text => this.childPrint(text));
+
+      let connectionAttempts = 0;
+      const attemptConnect = () => {
+        ++connectionAttempts;
+        this.stdout.write('.');
+        this.client.connect()
+          .then(null, () => {
+            // If it's failed to connect 10 times then print failed message
+            if (connectionAttempts >= 10) {
+              this.print(' failed to connect, please retry');
+              process.exit(1);
+            }
+            return delay(500).then(() => attemptConnect());
+          });
+      };
+
+      const { host, port } = this.options;
+      this.print(`connecting to ${host}:${port} ..`, true);
+      return attemptConnect();
     });
   }
 
-  clearline() {
+  clearLine() {
     if (this.stdout.isTTY) {
       this.stdout.cursorTo(0);
       this.stdout.clearLine(1);
@@ -111,8 +150,8 @@ class NodeInspector {
   }
 
   print(text, oneline = false) {
-    this.clearline();
-    this.stdout.write(oneline ? `${text}\n` : text);
+    this.clearLine();
+    this.stdout.write(oneline ? text : `${text}\n`);
   }
 
   childPrint(text) {

test/cli/launch.test.js

@@ -3,13 +3,9 @@ const tap = require('tap');
 
 const startCLI = require('./start-cli');
 
-function delay(t) {
-  return new Promise((resolve) => setTimeout(resolve, t));
-}
-
 tap.test('examples/empty.js', (t) => {
   const cli = startCLI(['examples/empty.js']);
-  return delay(1000)
+  return cli.waitForPrompt()
     .then(() => cli.quit())
     .then((code) => {
       t.match(cli.output, 'debug>', 'prints a prompt');

test/cli/start-cli.js

@@ -5,13 +5,26 @@ const CLI = require.resolve('../../cli.js');
 
 function startCLI(args) {
   const child = spawn(process.execPath, [CLI, ...args]);
+  let isFirstStdoutChunk = true;
 
   const outputBuffer = [];
   function bufferOutput(chunk) {
-    outputBuffer.push(chunk);
+    if (isFirstStdoutChunk) {
+      isFirstStdoutChunk = false;
+      outputBuffer.push(chunk.replace(/^debug>\s*/, ''));
+    } else {
+      outputBuffer.push(chunk);
+    }
   }
 
+  function getOutput() {
+    return outputBuffer.join('').toString()
+      .replace(/^[^\n]*[\b]/mg, '\n');
+  }
+
+  child.stdout.setEncoding('utf8');
   child.stdout.on('data', bufferOutput);
+  child.stderr.setEncoding('utf8');
   child.stderr.on('data', bufferOutput);
 
   if (process.env.VERBOSE === '1') {
@@ -26,9 +39,24 @@ function startCLI(args) {
       return output;
     },
 
+    waitForPrompt() {
+      return new Promise((resolve, reject) => {
+        function checkOutput() {
+          if (/debug>\s*$/.test(getOutput())) {
+            child.stdout.removeListener('data', checkOutput);
+            resolve();
+          }
+        }
+        child.on('exit', () => {
+          reject(new Error('Child quit while waiting for prompt'));
+        });
+        child.stdout.on('data', checkOutput);
+        checkOutput();
+      });
+    },
+
     get output() {
-      return Buffer.concat(outputBuffer).toString()
-        .replace(/^[^\n]*[\b]/mg, '\n');
+      return getOutput();
     },
 
     quit() {