Address Siva's and Mads' review request in debugger test

tests/standalone/debugger/debug_lib.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Library used by debugger wire protocol tests (standalone VM debugging).
 
 library DartDebugger;
 
 import "dart:io";
 import "dart:utf";
@@ skipping 24 matching lines @@
 
   String getNextMessage() {
     if (buffer == null) return null;
     int msgLen = objectLength();
     if (msgLen == 0) return null;
     String msg = null;
     if (msgLen == buffer.length) {
       msg = buffer;
       buffer = null;
     } else {
+      assert(msgLen < buffer.length);
       msg = buffer.substring(0, msgLen);
       buffer = buffer.substring(msgLen);
     }
     return msg;
   }
 
-  // Skip past a JSON object value.
+  // Returns the character length of the newxt json message in the
+  // buffer, or 0 if there is only a partial message in the buffer.
   // The object value must start with '{' and continues to the
   // matching '}'. No attempt is made to otherwise validate the contents
   // as JSON. If it is invalid, a later JSON.parse() will fail.
   int objectLength() {
     int skipWhitespace(int index) {
       while (index < buffer.length) {
         String char = buffer[index];
         if (char != " " && char != "\n" && char != "\r" && char != "\t") break;
         index++;
       }
       return index;
     }
     int skipString(int index) {
       assert(buffer[index - 1] == '"');
       while (index < buffer.length) {
         String char = buffer[index];
         if (char == '"') return index + 1;
         if (char == r'\') index++;
         if (index == buffer.length) return index;
         index++;
       }
       return index;
     }
     int index = 0;
     index = skipWhitespace(index);
     // Bail out if the first non-whitespace character isn't '{'.
     if (index == buffer.length || buffer[index] != '{') return 0;
-    int nexting = 0;
+    int nesting = 0;
     while (index < buffer.length) {
       String char = buffer[index++];
       if (char == '{') {
-        nexting++;
+        nesting++;
       } else if (char == '}') {
-        nexting--;
-        if (nexting == 0) return index;
+        nesting--;
+        if (nesting == 0) return index;
       } else if (char == '"') {
         // Strings can contain braces. Skip their content.
         index = skipString(index);
       }
     }
     return 0;
   }
 }
 
 
@@ skipping 10 matching lines @@
       if (bracketPos <= 0) return null;
       var indexStr = property.substring(bracketPos + 1, property.length - 1);
       try {
         index = int.parse(indexStr);
       } on FormatException {
         print("$indexStr is not a valid array index");
         return null;
       }
       property = property.substring(0, bracketPos);
     }
-        if (node is Map) {
+    if (node is Map) {
       node = node[property];
     } else {
       return null;
     }
     if (index != null) {
       if (node is List && node.length > index) {
         node = node[index];
       } else {
         return null;
       }
@@ skipping 27 matching lines @@
 class BreakpointEvent {
   String functionName;
   var template = { "event": "paused", "params": { "reason": "breakpoint" }};
 
   BreakpointEvent({String function: null}) {
     functionName = function;
   }
 
   void match(Debugger debugger) {
     var msg = debugger.currentMessage;
-    if (!matchMaps(template, msg)) debugger.error("message does not match $template");
+    if (!matchMaps(template, msg)) {
+      debugger.error("message does not match $template");
+    }
     var name = getJsonValue(msg, "params:callFrames[0]:functionName");
     if (name == "main") {
       // Extract script url of debugged script.
       var scriptUrl = getJsonValue(msg, "params:callFrames[0]:location:url");
       assert(scriptUrl != null);
       debugger.scriptUrl = scriptUrl;
     }
     if (functionName != null) {
       var name = getJsonValue(msg, "params:callFrames[0]:functionName");
       if (functionName != name) {
@@ skipping 15 matching lines @@
   int frameIndex;
   List<String> functionNames;
 
   FrameMatcher(this.frameIndex, this.functionNames);
 
   void match(Debugger debugger) {
     var msg = debugger.currentMessage;
     List frames = getJsonValue(msg, "params:callFrames");
     assert(frames != null);
     if (frames.length < functionNames.length) {
-      debugger.error("stack trace not long enough to match ${functionNames.length} frames");
+      debugger.error("stack trace not long enough "
+                     "to match ${functionNames.length} frames");
       return;
     }
     for (int i = 0; i < functionNames.length; i++) {
       var idx = i + frameIndex;
       var property = "params:callFrames[$idx]:functionName";
       var name = getJsonValue(msg, property);
       if (name == null) {
         debugger.error("property '$property' not found");
         return;
       }
@@ skipping 20 matching lines @@
   var template;
   Command();
   Command.resume() {
     template = {"id": 0, "command": "resume", "params": {"isolateId": 0}};
   }
   Command.step() {
     template = {"id": 0, "command": "stepOver", "params": {"isolateId": 0}};
   }
   Map makeMsg(int cmdId, int isolateId) {
     template["id"] = cmdId;
-    if ((template["params"] != null) && (template["params"]["isolateId"] != null)) {
+    if ((template["params"] != null)
+        && (template["params"]["isolateId"] != null)) {
       template["params"]["isolateId"] = isolateId;
     }
     return template;
   }
 
   void send(Debugger debugger) {
     template["id"] = debugger.seqNr;
     template["params"]["isolateId"] = debugger.isolateId;
     debugger.sendMessage(template);
   }
@@ skipping 88 matching lines @@
   // shutdown events, breakpoint resolution events, etc.
   bool handleImplicitEvents(Map<String,dynamic> msg) {
     if (msg["event"] == "isolate") {
       if (msg["params"]["reason"] == "created") {
         isolateId = msg["params"]["id"];
         assert(isolateId != null);
         print("Debuggee isolate id $isolateId created.");
       } else if (msg["params"]["reason"] == "shutdown") {
         print("Debuggee isolate id ${msg["params"]["id"]} shut down.");
         shutdownEventSeen = true;
+        if (script.currentEntry != null) {
+          error("Premature isolate shutdown event seen.");
+        }
       }
       return true;
     } else if (msg["event"] == "breakpointResolved") {
       // Ignore the event. We may want to maintain a table of
       // breakpoints in the future.
       return true;
     }
     return false;
   }
 
@@ skipping 139 matching lines @@
   verboseWire = options.arguments.contains("--wire");
 
   var targetOpts = [ "--debug:$debugPort" ];
   if (showDebuggeeOutput) targetOpts.add("--verbose_debug");
   targetOpts.add(options.script);
   targetOpts.add("--debuggee");
 
   Process.start(options.executable, targetOpts).then((Process process) {
     print("Debug target process started");
     process.stdin.close();
+    process.stdout.onData = process.stdout.read;
+    process.stderr.onData = process.stderr.read;
     process.onExit = (int exitCode) {
       print("Debug target process exited with exit code $exitCode");
     };
     var debugger = new Debugger(process, debugPort);
     stdin.onClosed = () => debugger.close();
     stdin.onError = (error) => debugger.close();
     debugger.runScript(script);
   });
   return true;
 }