debugger: Work towards interactive restart

lib/_debugger.js

@@ -16,19 +16,9 @@ exports.start = function () {
 var child;
 var c;
 var term;
+var args = process.argv.slice(2);
+args.unshift('--debug-brk');
 
-function trySpawn(cb) {
-  var args = process.argv.slice(2);
-  args.unshift('--debug-brk');
-
-  console.log(args);
-
-  child = spawn(process.execPath, args, { customFds: [0, 1, 2] });
-
-  setTimeout(function () {
-    tryConnect(cb);
-  }, 100);
-}
 
 function tryConnect(cb) {
   c = new Client();
@@ -84,6 +74,27 @@ function tryConnect(cb) {
   });
 }
 
+
+function trySpawn(cb) {
+  if (child) {
+    child.kill();
+    child = null;
+  }
+
+  if (c) {
+    c.destroy();
+    c = null;
+  }
+
+  child = spawn(process.execPath, args, { customFds: [0, 1, 2] });
+
+  console.log("trySpawn");
+  setTimeout(function () {
+    console.log("after timeout");
+    tryConnect(cb);
+  }, 1000);
+}
+
 //
 // Parser/Serializer for V8 debugger protocol
 // http://code.google.com/p/v8/wiki/DebuggerProtocol
@@ -305,7 +316,7 @@ Client.prototype.step = function(action, count, cb) {
 
 
 
-var helpMessage = "Commands: print, step, next, continue, scripts, backtrace, version, quit";
+var helpMessage = "Commands: run, print, step, next, continue, scripts, backtrace, version, quit";
 
 function SourceUnderline(source_text, position) {
   if (!source_text) {
@@ -348,6 +359,23 @@ function SourceInfo(body) {
 }
 
 
+var restartQuestionPrompt = "The program being debugged has " +
+                            "been started already.\n" +
+                            "Start it from the beginning? (y or n): ";
+
+function restartQuestion (cb) {
+  term.question(restartQuestionPrompt, function (answer) {
+    if (/^y(es)?$/i.test(answer)) {
+      cb(true);
+    } else if (/^n(o)?$/i.test(answer)) {
+      cb(false);
+    } else {
+      console.log("Please answer y or n.");
+      restartQuestion(cb);
+    }
+  });
+}
+
 
 function startInterface() {
 
@@ -387,11 +415,26 @@ function startInterface() {
       tryQuit();
 
     } else if (/^r(un)?/.test(cmd)) {
-      trySpawn(function () {
-        c.reqContinue(function (res) {
-          // Wait for break point. (disable raw mode?)
+      if (child) {
+        restartQuestion(function (yes) {
+          if (!yes) {
+            term.prompt();
+          } else {
+            console.log("restarting...");
+            trySpawn(function () {
+              c.reqContinue(function (res) {
+                // Wait for break point. (disable raw mode?)
+              });
+            });
+          }
         });
-      });
+      } else {
+        trySpawn(function () {
+          c.reqContinue(function (res) {
+            // Wait for break point. (disable raw mode?)
+          });
+        });
+      }
 
     } else if (/^help/.test(cmd)) {
       console.log(helpMessage);