Bug 918802 - Move the debugger's pretty printing into a worker; r=past

browser/devtools/debugger/test/browser.ini

@@ -20,6 +20,9 @@ support-files =
   code_script-switching-02.js
   code_test-editor-mode
   code_ugly.js
+  code_ugly-2.js
+  code_ugly-3.js
+  code_ugly-4.js
   doc_binary_search.html
   doc_blackboxing.html
   doc_closures.html
@@ -41,6 +44,7 @@ support-files =
   doc_minified.html
   doc_pause-exceptions.html
   doc_pretty-print.html
+  doc_pretty-print-2.html
   doc_recursion-stack.html
   doc_script-switching-01.html
   doc_script-switching-02.html
@@ -104,6 +108,9 @@ support-files =
 [browser_dbg_pretty-print-04.js]
 [browser_dbg_pretty-print-05.js]
 [browser_dbg_pretty-print-06.js]
+[browser_dbg_pretty-print-07.js]
+[browser_dbg_pretty-print-08.js]
+[browser_dbg_pretty-print-09.js]
 [browser_dbg_progress-listener-bug.js]
 [browser_dbg_reload-preferred-script-01.js]
 [browser_dbg_reload-preferred-script-02.js]

browser/devtools/debugger/test/browser_dbg_pretty-print-07.js

@@ -0,0 +1,46 @@
+/* -*- Mode: javascript; js-indent-level: 2; -*- */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test basic pretty printing functionality. Would be an xpcshell test, except
+// for bug 921252.
+
+let gTab, gDebuggee, gPanel, gClient, gThreadClient;
+
+const TAB_URL = EXAMPLE_URL + "doc_pretty-print-2.html";
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gClient = gPanel.panelWin.gClient;
+    gThreadClient = gPanel.panelWin.DebuggerController.activeThread;
+
+    findSource();
+  });
+}
+
+function findSource() {
+  gThreadClient.getSources(({ error, sources }) => {
+    ok(!error);
+    sources = sources.filter(s => s.url.contains('code_ugly-2.js'));
+    is(sources.length, 1);
+    prettyPrintSource(sources[0]);
+  });
+}
+
+function prettyPrintSource(source) {
+  gThreadClient.source(source).prettyPrint(4, testPrettyPrinted);
+}
+
+function testPrettyPrinted({ error, source}) {
+  ok(!error);
+  ok(source.contains("\n    "));
+
+  closeDebuggerAndFinish(gPanel);
+}
+
+registerCleanupFunction(function() {
+  gTab = gDebuggee = gPanel = gClient = gThreadClient = null;
+});

browser/devtools/debugger/test/browser_dbg_pretty-print-08.js

@@ -0,0 +1,95 @@
+/* -*- Mode: javascript; js-indent-level: 2; -*- */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test stepping through pretty printed sources.
+
+let gTab, gDebuggee, gPanel, gClient, gThreadClient, gSource;
+
+const TAB_URL = EXAMPLE_URL + "doc_pretty-print-2.html";
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gClient = gPanel.panelWin.gClient;
+    gThreadClient = gPanel.panelWin.DebuggerController.activeThread;
+
+    gDebuggee.noop = x => x;
+    findSource();
+  });
+}
+
+let CODE_URL;
+
+const BP_LOCATION = {
+  line: 5,
+  column: 11
+};
+
+function findSource() {
+  gThreadClient.getSources(({ error, sources }) => {
+    ok(!error);
+    sources = sources.filter(s => s.url.contains("code_ugly-3.js"));
+    is(sources.length, 1);
+    [gSource] = sources;
+    CODE_URL = BP_LOCATION.url = gSource.url;
+
+    prettyPrintSource(sources[0]);
+  });
+}
+
+function prettyPrintSource(source) {
+  gThreadClient.source(gSource).prettyPrint(2, runCode);
+}
+
+function runCode({ error }) {
+  ok(!error);
+  gClient.addOneTimeListener("paused", testDbgStatement);
+  gDebuggee.main3();
+}
+
+function testDbgStatement(event, { why, frame }) {
+  is(why.type, "debuggerStatement");
+  const { url, line, column } = frame.where;
+  is(url, CODE_URL);
+  is(line, 3);
+  setBreakpoint();
+}
+
+function setBreakpoint() {
+  gThreadClient.setBreakpoint(BP_LOCATION, ({ error, actualLocation }) => {
+    ok(!error);
+    ok(!actualLocation);
+    testStepping();
+  });
+}
+
+function testStepping() {
+  gClient.addOneTimeListener("paused", (event, { why, frame }) => {
+    is(why.type, "resumeLimit");
+    const { url, line } = frame.where;
+    is(url, CODE_URL);
+    is(line, 4);
+    testHitBreakpoint();
+  });
+  gThreadClient.stepIn();
+}
+
+function testHitBreakpoint() {
+  gClient.addOneTimeListener("paused", (event, { why, frame }) => {
+    is(why.type, "breakpoint");
+    const { url, line, column } = frame.where;
+    is(url, CODE_URL);
+    is(line, BP_LOCATION.line);
+    is(column, BP_LOCATION.column);
+
+    resumeDebuggerThenCloseAndFinish(gPanel);
+  });
+  gThreadClient.resume();
+}
+
+registerCleanupFunction(function() {
+  gTab = gDebuggee = gPanel = gClient = gThreadClient = gSource = null;
+});

browser/devtools/debugger/test/browser_dbg_pretty-print-09.js

@@ -0,0 +1,73 @@
+/* -*- Mode: javascript; js-indent-level: 2; -*- */
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test pretty printing source mapped sources.
+
+var gDebuggee;
+var gClient;
+var gThreadClient;
+var gSource;
+
+let gTab, gDebuggee, gPanel, gClient, gThreadClient;
+
+const TAB_URL = EXAMPLE_URL + "doc_pretty-print-2.html";
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gClient = gPanel.panelWin.gClient;
+    gThreadClient = gPanel.panelWin.DebuggerController.activeThread;
+
+    findSource();
+  });
+}
+
+const dataUrl = s => "data:text/javascript," + s;
+
+// These should match the instructions in code_ugly-4.js.
+const A = "function a(){b()}";
+const A_URL = dataUrl(A);
+const B = "function b(){debugger}";
+const B_URL = dataUrl(B);
+
+function findSource() {
+  gThreadClient.getSources(({ error, sources }) => {
+    ok(!error);
+    sources = sources.filter(s => s.url === B_URL);
+    is(sources.length, 1);
+    prettyPrint(sources[0]);
+  });
+}
+
+function prettyPrint(source) {
+  gThreadClient.source(source).prettyPrint(2, runCode);
+}
+
+function runCode({ error }) {
+  ok(!error);
+  gClient.addOneTimeListener("paused", testDbgStatement);
+  gDebuggee.a();
+}
+
+function testDbgStatement(event, { frame, why }) {
+  dump("FITZGEN: inside testDbgStatement\n");
+
+  try {
+    is(why.type, "debuggerStatement");
+    const { url, line, column } = frame.where;
+    is(url, B_URL);
+    is(line, 2);
+    is(column, 2);
+
+    resumeDebuggerThenCloseAndFinish(gPanel);
+  } catch (e) {
+    dump("FITZGEN: got an error! " + DevToolsUtils.safeErrorString(e) + "\n");
+  }
+}
+
+registerCleanupFunction(function() {
+  gTab = gDebuggee = gPanel = gClient = gThreadClient = null;
+});

browser/devtools/debugger/test/code_ugly-2.js

@@ -0,0 +1 @@
+function main2() { var a = 1 + 3; var b = a++; return b + a; }

browser/devtools/debugger/test/code_ugly-3.js

@@ -0,0 +1 @@
+function main3() { var a = 1; debugger; noop(a); return 10; };

browser/devtools/debugger/test/code_ugly-4.js

@@ -0,0 +1,24 @@
+function a(){b()}function b(){debugger}
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiYWJjLmpzIiwic291cmNlcyI6WyJkYXRhOnRleHQvamF2YXNjcmlwdCxmdW5jdGlvbiBhKCl7YigpfSIsImRhdGE6dGV4dC9qYXZhc2NyaXB0LGZ1bmN0aW9uIGIoKXtkZWJ1Z2dlcn0iXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6IkFBQUEsaUJDQUEsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMifQ==
+
+// Generate this file by evaluating the following in a browser-environment
+// scratchpad:
+//
+//    Components.utils.import('resource://gre/modules/devtools/SourceMap.jsm');
+//
+//    let dataUrl = s => "data:text/javascript," + s;
+//
+//    let A = "function a(){b()}";
+//    let A_URL = dataUrl(A);
+//    let B = "function b(){debugger}";
+//    let B_URL = dataUrl(B);
+//
+//    let result = (new SourceNode(null, null, null, [
+//      new SourceNode(1, 0, A_URL, A),
+//      B.split("").map((ch, i) => new SourceNode(1, i, B_URL, ch))
+//    ])).toStringWithSourceMap({
+//      file: "abc.js"
+//    });
+//
+//    result.code + "\n//# sourceMappingURL=data:application/json;base64," + btoa(JSON.stringify(result.map));
+

browser/devtools/debugger/test/doc_pretty-print-2.html

@@ -0,0 +1,10 @@
+<!-- Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/publicdomain/zero/1.0/ -->
+<!DOCTYPE html>
+<head>
+  <meta charset="utf-8"/>
+  <title>Debugger Pretty Printing Test Page</title>
+</head>
+<script src="code_ugly-2.js"></script>
+<script src="code_ugly-3.js"></script>
+<script src="code_ugly-4.js"></script>

toolkit/devtools/DevToolsUtils.js

@@ -6,6 +6,9 @@
 
 /* General utilities used throughout devtools. */
 
+let { Promise: promise } = Components.utils.import("resource://gre/modules/commonjs/sdk/core/promise.js", {});
+let { Services } = Components.utils.import("resource://gre/modules/Services.jsm", {});
+
 /**
  * Turn the error |aError| into a string, without fail.
  */
@@ -79,3 +82,55 @@ this.makeInfallible = function makeInfallible(aHandler, aName) {
     }
   }
 }
+
+const executeSoon = aFn => {
+  Services.tm.mainThread.dispatch({
+    run: this.makeInfallible(aFn)
+  }, Components.interfaces.nsIThread.DISPATCH_NORMAL);
+}
+
+/**
+ * Like Array.prototype.forEach, but doesn't cause jankiness when iterating over
+ * very large arrays by yielding to the browser and continuing execution on the
+ * next tick.
+ *
+ * @param Array aArray
+ *        The array being iterated over.
+ * @param Function aFn
+ *        The function called on each item in the array.
+ * @returns Promise
+ *          A promise that is resolved once the whole array has been iterated
+ *          over.
+ */
+this.yieldingEach = function yieldingEach(aArray, aFn) {
+  const deferred = promise.defer();
+
+  let i = 0;
+  let len = aArray.length;
+
+  (function loop() {
+    const start = Date.now();
+
+    while (i < len) {
+      // Don't block the main thread for longer than 16 ms at a time. To
+      // maintain 60fps, you have to render every frame in at least 16ms; we
+      // aren't including time spent in non-JS here, but this is Good
+      // Enough(tm).
+      if (Date.now() - start > 16) {
+        executeSoon(loop);
+        return;
+      }
+
+      try {
+        aFn(aArray[i++]);
+      } catch (e) {
+        deferred.reject(e);
+        return;
+      }
+    }
+
+    deferred.resolve();
+  }());
+
+  return deferred.promise;
+}

toolkit/devtools/DevToolsUtils.jsm

@@ -21,5 +21,6 @@ Components.classes["@mozilla.org/moz/jssubscript-loader;1"]
 this.DevToolsUtils = {
   safeErrorString: safeErrorString,
   reportException: reportException,
-  makeInfallible: makeInfallible
+  makeInfallible: makeInfallible,
+  yieldingEach: yieldingEach
 };

toolkit/devtools/escodegen/UPGRADING.md

@@ -30,3 +30,23 @@ JSON data is exported, and we can load package.json as a module.
 6. Copy the estraverse.js that escodegen depends on into our tree:
 
        $ cp node_modules/estraverse/estraverse.js /path/to/mozilla-central/devtools/escodegen/estraverse.js
+
+7. Build the version of the escodegen that we can use in workers:
+
+   First we need to alias `self` as `window`:
+
+       $ echo 'let window = self;' >> /path/to/mozilla-central/toolkit/devtools/escodegen/escodegen.worker.js
+
+   Then we need to add the browser build of the source map library:
+
+       $ git clone https://github.com/mozilla/source-map
+       $ cd source-map
+       $ git co <latest release tag compatible with escodegen>
+       $ npm run-script build
+       $ cat dist/source-map.js >> /path/to/mozilla-central/toolkit/devtools/escodegen/escodegen.worker.js
+
+   Then we need to build the browser version of escodegen:
+
+       $ cd /path/to/escodegen
+       $ npm run-script build
+       $ cat escodegen.browser.js >> /path/to/mozilla-central/toolkit/devtools/escodegen/escodegen.worker.js

toolkit/devtools/escodegen/moz.build

@@ -10,6 +10,7 @@ JS_MODULES_PATH = 'modules/devtools/escodegen'
 
 EXTRA_JS_MODULES += [
     'escodegen.js',
+    'escodegen.worker.js',
     'estraverse.js',
     'package.json.js',
 ]

toolkit/devtools/server/actors/pretty-print-worker.js

@@ -0,0 +1,54 @@
+/* -*- Mode: javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; js-indent-level: 2; -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This file is meant to be loaded as a ChromeWorker. It accepts messages which
+ * have data of the form:
+ *
+ *     { id, url, indent, ast }
+ *
+ * Where `id` is a unique ID to identify this request, `url` is the url of the
+ * source being pretty printed, `indent` is the number of spaces to indent the
+ * code by, and `ast` is the source's abstract syntax tree.
+ *
+ * On success, the worker responds with a message of the form:
+ *
+ *     { id, code, mappings }
+ *
+ * Where `id` is the same unique ID from the request, `code` is the pretty
+ * printed source text, and `mappings` is an array or source mappings from the
+ * pretty printed code to the AST's source locations.
+ *
+ * In the case of an error, the worker responds with a message of the form:
+ *
+ *     { error }
+ */
+
+importScripts("resource://gre/modules/devtools/escodegen/escodegen.worker.js");
+
+self.onmessage = ({ data: { id, url, indent, ast } }) => {
+  try {
+    const prettified = escodegen.generate(ast, {
+      format: {
+        indent: {
+          style: " ".repeat(indent)
+        }
+      },
+      sourceMap: url,
+      sourceMapWithCode: true
+    });
+
+    self.postMessage({
+      id: id,
+      code: prettified.code,
+      mappings: prettified.map._mappings
+    });
+  } catch (e) {
+    self.postMessage({
+      error: e.message + "\n" + e.stack
+    });
+  }
+};

toolkit/devtools/server/actors/script.js

@@ -467,6 +467,38 @@ ThreadActor.prototype = {
     return this._sources;
   },
 
+  _prettyPrintWorker: null,
+  get prettyPrintWorker() {
+    if (!this._prettyPrintWorker) {
+      this._prettyPrintWorker = new ChromeWorker(
+        "resource://gre/modules/devtools/server/actors/pretty-print-worker.js");
+
+      this._prettyPrintWorker.addEventListener(
+        "error", this._onPrettyPrintError, false);
+
+      if (wantLogging) {
+        this._prettyPrintWorker.addEventListener("message", this._onPrettyPrintMsg, false);
+
+        const postMsg = this._prettyPrintWorker.postMessage;
+        this._prettyPrintWorker.postMessage = data => {
+          dumpn("Sending message to prettyPrintWorker: "
+                + JSON.stringify(data, null, 2) + "\n");
+          return postMsg.call(this._prettyPrintWorker, data);
+        };
+      }
+    }
+    return this._prettyPrintWorker;
+  },
+
+  _onPrettyPrintError: function (error) {
+    reportError(new Error(error));
+  },
+
+  _onPrettyPrintMsg: function ({ data }) {
+    dumpn("Received message from prettyPrintWorker: "
+          + JSON.stringify(data, null, 2) + "\n");
+  },
+
   /**
    * Keep track of all of the nested event loops we use to pause the debuggee
    * when we hit a breakpoint/debugger statement/etc in one place so we can
@@ -598,6 +630,15 @@ ThreadActor.prototype = {
 
     this.clearDebuggees();
 
+    if (this._prettyPrintWorker) {
+      this._prettyPrintWorker.removeEventListener(
+        "error", this._onPrettyPrintError, false);
+      this._prettyPrintWorker.removeEventListener(
+        "message", this._onPrettyPrintMsg, false);
+      this._prettyPrintWorker.terminate();
+      this._prettyPrintWorker = null;
+    }
+
     if (!this.dbg) {
       return;
     }
@@ -2335,6 +2376,10 @@ SourceActor.prototype = {
   get threadActor() this._threadActor,
   get url() this._url,
 
+  get prettyPrintWorker() {
+    return this.threadActor.prettyPrintWorker;
+  },
+
   form: function SA_form() {
     return {
       actor: this.actorID,
@@ -2401,7 +2446,7 @@ SourceActor.prototype = {
   onPrettyPrint: function ({ indent }) {
     return this._getSourceText()
       .then(this._parseAST)
-      .then(this._generatePrettyCodeAndMap(indent))
+      .then(this._sendToPrettyPrintWorker(indent))
       .then(this._invertSourceMap)
       .then(this._saveMap)
       .then(this.onSource)
@@ -2420,23 +2465,45 @@ SourceActor.prototype = {
   },
 
   /**
-   * Take the number of spaces to indent and return a function that takes an AST
-   * and generates code and a source map from the ugly code to the pretty code.
+   * Return a function that sends a request to the pretty print worker, waits on
+   * the worker's response, and then returns the pretty printed code.
+   *
+   * @param Number aIndent
+   *        The number of spaces to indent by the code by, when we send the
+   *        request to the pretty print worker.
+   * @returns Function
+   *          Returns a function which takes an AST, and returns a promise that
+   *          is resolved with `{ code, mappings }` where `code` is the pretty
+   *          printed code, and `mappings` is an array of source mappings.
    */
-  _generatePrettyCodeAndMap: function SA__generatePrettyCodeAndMap(aNumSpaces) {
-    let indent = "";
-    for (let i = 0; i < aNumSpaces; i++) {
-      indent += " ";
-    }
-    return aAST => escodegen.generate(aAST, {
-      format: {
-        indent: {
-          style: indent
+  _sendToPrettyPrintWorker: function SA__sendToPrettyPrintWorker(aIndent) {
+    return aAST => {
+      const deferred = promise.defer();
+      const id = Math.random();
+
+      const onReply = ({ data }) => {
+        if (data.id !== id) {
+          return;
         }
-      },
-      sourceMap: this._url,
-      sourceMapWithCode: true
-    });
+        this.prettyPrintWorker.removeEventListener("message", onReply, false);
+
+        if (data.error) {
+          deferred.reject(new Error(data.error));
+        } else {
+          deferred.resolve(data);
+        }
+      };
+
+      this.prettyPrintWorker.addEventListener("message", onReply, false);
+      this.prettyPrintWorker.postMessage({
+        id: id,
+        url: this._url,
+        indent: aIndent,
+        ast: aAST
+      });
+
+      return deferred.promise;
+    };
   },
 
   /**
@@ -2447,35 +2514,55 @@ SourceActor.prototype = {
    *
    * Note that the source map is modified in place.
    */
-  _invertSourceMap: function SA__invertSourceMap({ code, map }) {
-    // XXX bug 918802: Monkey punch the source map consumer, because iterating
-    // over all mappings and inverting each of them, and then creating a new
-    // SourceMapConsumer is *way* too slow.
+  _invertSourceMap: function SA__invertSourceMap({ code, mappings }) {
+    const generator = new SourceMapGenerator({ file: this._url });
+    return DevToolsUtils.yieldingEach(mappings, m => {
+      let mapping = {
+        generated: {
+          line: m.generatedLine,
+          column: m.generatedColumn
+        }
+      };
+      if (m.source) {
+        mapping.source = m.source;
+        mapping.original = {
+          line: m.originalLine,
+          column: m.originalColumn
+        };
+        mapping.name = m.name;
+      }
+      generator.addMapping(mapping);
+    }).then(() => {
+      generator.setSourceContent(this._url, code);
+      const consumer = SourceMapConsumer.fromSourceMap(generator);
 
-    map.setSourceContent(this._url, code);
-    const consumer = new SourceMapConsumer.fromSourceMap(map);
-    const getOrigPos = consumer.originalPositionFor.bind(consumer);
-    const getGenPos = consumer.generatedPositionFor.bind(consumer);
+      // XXX bug 918802: Monkey punch the source map consumer, because iterating
+      // over all mappings and inverting each of them, and then creating a new
+      // SourceMapConsumer is slow.
 
-    consumer.originalPositionFor = ({ line, column }) => {
-      const location = getGenPos({
+      const getOrigPos = consumer.originalPositionFor.bind(consumer);
+      const getGenPos = consumer.generatedPositionFor.bind(consumer);
+
+      consumer.originalPositionFor = ({ line, column }) => {
+        const location = getGenPos({
+          line: line,
+          column: column,
+          source: this._url
+        });
+        location.source = this._url;
+        return location;
+      };
+
+      consumer.generatedPositionFor = ({ line, column }) => getOrigPos({
         line: line,
-        column: column,
-        source: this._url
+        column: column
       });
-      location.source = this._url;
-      return location;
-    };
 
-    consumer.generatedPositionFor = ({ line, column }) => getOrigPos({
-      line: line,
-      column: column
+      return {
+        code: code,
+        map: consumer
+      };
     });
-
-    return {
-      code: code,
-      map: consumer
-    };
   },
 
   /**

toolkit/devtools/server/dbg-server.jsm

@@ -37,6 +37,7 @@ var systemPrincipal = Cc["@mozilla.org/systemprincipal;1"]
                       .createInstance(Ci.nsIPrincipal);
 
 var gGlobal = Cu.Sandbox(systemPrincipal);
+gGlobal.ChromeWorker = ChromeWorker;
 Cu.evalInSandbox(loadSubScript, gGlobal, "1.8");
 gGlobal.loadSubScript("resource://gre/modules/devtools/server/main.js");
 

toolkit/devtools/server/tests/unit/test_pretty_print-01.js

@@ -1,42 +0,0 @@
-/* -*- Mode: javascript; js-indent-level: 2; -*- */
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-var gDebuggee;
-var gClient;
-var gThreadClient;
-
-// Test basic pretty printing functionality
-
-function run_test() {
-  initTestDebuggerServer();
-  gDebuggee = addTestGlobal("test-pretty-print");
-  gClient = new DebuggerClient(DebuggerServer.connectPipe());
-  gClient.connect(function() {
-    attachTestTabAndResume(gClient, "test-pretty-print", function(aResponse, aTabClient, aThreadClient) {
-      gThreadClient = aThreadClient;
-      evalCode();
-    });
-  });
-  do_test_pending();
-}
-
-function evalCode() {
-  gClient.addOneTimeListener("newSource", prettyPrintSource);
-  const code = "" + function main() { let a = 1 + 3; let b = a++; return b + a; };
-  Cu.evalInSandbox(
-    code,
-    gDebuggee,
-    "1.8",
-    "data:text/javascript," + code);
-}
-
-function prettyPrintSource(event, { source }) {
-  gThreadClient.source(source).prettyPrint(4, testPrettyPrinted);
-}
-
-function testPrettyPrinted({ error, source}) {
-  do_check_true(!error);
-  do_check_true(source.contains("\n    "));
-  finishClient(gClient);
-}

toolkit/devtools/server/tests/unit/test_pretty_print-02.js

@@ -1,94 +0,0 @@
-/* -*- Mode: javascript; js-indent-level: 2; -*- */
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-var gDebuggee;
-var gClient;
-var gThreadClient;
-var gSource;
-
-// Test stepping through pretty printed sources.
-
-function run_test() {
-  initTestDebuggerServer();
-  gDebuggee = addTestGlobal("test-pretty-print");
-  gDebuggee.noop = x => x;
-  gClient = new DebuggerClient(DebuggerServer.connectPipe());
-  gClient.connect(function() {
-    attachTestTabAndResume(gClient, "test-pretty-print", function(aResponse, aTabClient, aThreadClient) {
-      gThreadClient = aThreadClient;
-      evalCode();
-    });
-  });
-  do_test_pending();
-}
-
-const CODE = "" + function main() { var a = 1; debugger; noop(a); return 10; };
-const CODE_URL = "data:text/javascript," + CODE;
-
-const BP_LOCATION = {
-  url: CODE_URL,
-  line: 5,
-  column: 2
-};
-
-function evalCode() {
-  gClient.addOneTimeListener("newSource", prettyPrintSource);
-  Cu.evalInSandbox(
-    CODE,
-    gDebuggee,
-    "1.8",
-    CODE_URL,
-    1
-  );
-}
-
-function prettyPrintSource(event, { source }) {
-  gSource = source;
-  gThreadClient.source(gSource).prettyPrint(2, runCode);
-}
-
-function runCode({ error }) {
-  do_check_true(!error);
-  gClient.addOneTimeListener("paused", testDbgStatement);
-  gDebuggee.main();
-}
-
-function testDbgStatement(event, { why, frame }) {
-  do_check_eq(why.type, "debuggerStatement");
-  const { url, line, column } = frame.where;
-  do_check_eq(url, CODE_URL);
-  do_check_eq(line, 3);
-  setBreakpoint();
-}
-
-function setBreakpoint() {
-  gThreadClient.setBreakpoint(BP_LOCATION, ({ error, actualLocation }) => {
-    do_check_true(!error);
-    do_check_true(!actualLocation);
-    testStepping();
-  });
-}
-
-function testStepping() {
-  gClient.addOneTimeListener("paused", (event, { why, frame }) => {
-    do_check_eq(why.type, "resumeLimit");
-    const { url, line } = frame.where;
-    do_check_eq(url, CODE_URL);
-    do_check_eq(line, 4);
-    testHitBreakpoint();
-  });
-  gThreadClient.stepIn();
-}
-
-function testHitBreakpoint() {
-  gClient.addOneTimeListener("paused", (event, { why, frame }) => {
-    do_check_eq(why.type, "breakpoint");
-    const { url, line, column } = frame.where;
-    do_check_eq(url, CODE_URL);
-    do_check_eq(line, BP_LOCATION.line);
-    do_check_eq(column, BP_LOCATION.column);
-    finishClient(gClient);
-  });
-  gThreadClient.resume();
-}

toolkit/devtools/server/tests/unit/test_pretty_print-03.js

@@ -1,74 +0,0 @@
-/* -*- Mode: javascript; js-indent-level: 2; -*- */
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-// Test pretty printing source mapped sources.
-
-var gDebuggee;
-var gClient;
-var gThreadClient;
-var gSource;
-
-Components.utils.import('resource:///modules/devtools/SourceMap.jsm');
-
-function run_test() {
-  initTestDebuggerServer();
-  gDebuggee = addTestGlobal("test-pretty-print");
-  gClient = new DebuggerClient(DebuggerServer.connectPipe());
-  gClient.connect(function() {
-    attachTestTabAndResume(gClient, "test-pretty-print", function(aResponse, aTabClient, aThreadClient) {
-      gThreadClient = aThreadClient;
-      evalCode();
-    });
-  });
-  do_test_pending();
-}
-
-const dataUrl = s => "data:text/javascript," + s;
-
-const A = "function a(){b()}";
-const A_URL = dataUrl(A);
-const B = "function b(){debugger}";
-const B_URL = dataUrl(B);
-
-function evalCode() {
-  let { code, map } = (new SourceNode(null, null, null, [
-    new SourceNode(1, 0, A_URL, A),
-    B.split("").map((ch, i) => new SourceNode(1, i, B_URL, ch))
-  ])).toStringWithSourceMap({
-    file: "abc.js"
-  });
-
-  code += "//# sourceMappingURL=data:text/json;base64," + btoa(map.toString());
-
-  gClient.addListener("newSource", waitForB);
-  Components.utils.evalInSandbox(code, gDebuggee, "1.8",
-                                 "http://example.com/foo.js", 1);
-}
-
-function waitForB(event, { source }) {
-  if (source.url !== B_URL) {
-    return;
-  }
-  gClient.removeListener("newSource", waitForB);
-  prettyPrint(source);
-}
-
-function prettyPrint(source) {
-  gThreadClient.source(source).prettyPrint(2, runCode);
-}
-
-function runCode({ error }) {
-  do_check_true(!error);
-  gClient.addOneTimeListener("paused", testDbgStatement);
-  gDebuggee.a();
-}
-
-function testDbgStatement(event, { frame, why }) {
-  do_check_eq(why.type, "debuggerStatement");
-  const { url, line, column } = frame.where;
-  do_check_eq(url, B_URL);
-  do_check_eq(line, 2);
-  do_check_eq(column, 2);
-  finishClient(gClient);
-}

toolkit/devtools/server/tests/unit/xpcshell.ini

@@ -169,9 +169,6 @@ reason = bug 820380
 [test_longstringactor.js]
 [test_longstringgrips-01.js]
 [test_longstringgrips-02.js]
-[test_pretty_print-01.js]
-[test_pretty_print-02.js]
-[test_pretty_print-03.js]
 [test_source-01.js]
 skip-if = toolkit == "gonk"
 reason = bug 820380

toolkit/devtools/server/transport.js

@@ -59,7 +59,7 @@ this.DebuggerTransport = function DebuggerTransport(aInput, aOutput)
 DebuggerTransport.prototype = {
   /**
    * Transmit a packet.
-   * 
+   *
    * This method returns immediately, without waiting for the entire
    * packet to be transmitted, registering event handlers as needed to
    * transmit the entire packet. Packets are transmitted in the order

toolkit/devtools/sourcemap/SourceMap.jsm

@@ -1258,7 +1258,12 @@ define('source-map/source-map-generator', ['require', 'exports', 'module' ,  'so
         return;
       }
       else {
-        throw new Error('Invalid mapping.');
+        throw new Error('Invalid mapping: ' + JSON.stringify({
+          generated: aGenerated,
+          source: aSource,
+          orginal: aOriginal,
+          name: aName
+        }));
       }
     };
 
@@ -1335,6 +1340,9 @@ define('source-map/source-map-generator', ['require', 'exports', 'module' ,  'so
   SourceMapGenerator.prototype._generateSourcesContent =
     function SourceMapGenerator_generateSourcesContent(aSources, aSourceRoot) {
       return aSources.map(function (source) {
+        if (!this._sourcesContents) {
+          return null;
+        }
         if (aSourceRoot) {
           source = util.relative(aSourceRoot, source);
         }