diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_file-reload.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_file-reload.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,63 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests that source contents are invalidated when the target navigates.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_random-javascript.html";
+const JS_URL = EXAMPLE_URL + "sjs_random-javascript.sjs";
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    let gDebugger = aPanel.panelWin;
+    let gEditor = gDebugger.DebuggerView.editor;
+    let gSources = gDebugger.DebuggerView.Sources;
+    let gControllerSources = gDebugger.DebuggerController.SourceScripts;
+
+    Task.spawn(function() {
+      yield waitForSourceShown(aPanel, JS_URL);
+
+      is(gSources.itemCount, 1,
+        "There should be one source displayed in the view.")
+      is(gSources.selectedValue, JS_URL,
+        "The correct source is currently selected in the view.");
+      ok(gEditor.getText().contains("bacon"),
+        "The currently shown source contains bacon. Mmm, delicious!");
+
+      let { source } = gSources.selectedItem.attachment;
+      let [, firstText] = yield gControllerSources.getText(source);
+      let firstNumber = parseFloat(firstText.match(/\d\.\d+/)[0]);
+
+      is(firstText, gEditor.getText(),
+        "gControllerSources.getText() returned the expected contents.");
+      ok(firstNumber <= 1 && firstNumber >= 0,
+        "The generated number seems to be created correctly.");
+
+      yield reloadActiveTab(aPanel, gDebugger.EVENTS.SOURCE_SHOWN);
+
+      is(gSources.itemCount, 1,
+        "There should be one source displayed in the view after reloading.")
+      is(gSources.selectedValue, JS_URL,
+        "The correct source is currently selected in the view after reloading.");
+      ok(gEditor.getText().contains("bacon"),
+        "The newly shown source contains bacon. Mmm, delicious!");
+
+      let { source } = gSources.selectedItem.attachment;
+      let [, secondText] = yield gControllerSources.getText(source);
+      let secondNumber = parseFloat(secondText.match(/\d\.\d+/)[0]);
+
+      is(secondText, gEditor.getText(),
+        "gControllerSources.getText() returned the expected contents.");
+      ok(secondNumber <= 1 && secondNumber >= 0,
+        "The generated number seems to be created correctly.");
+
+      isnot(firstText, secondText,
+        "The displayed sources were different across reloads.");
+      isnot(firstNumber, secondNumber,
+        "The displayed sources differences were correct across reloads.");
+
+      yield closeDebuggerAndFinish(aPanel);
+    });
+  });
+}