Bug 1565578 - 'Step in' exits function. r=loganfsmyth

Differential Revision: https://phabricator.services.mozilla.com/D38769

--HG--
extra : moz-landing-system : lando

devtools/server/actors/thread.js

@@ -950,15 +950,10 @@ const ThreadActor = ActorClassWithSpec(threadSpec, {
     const thread = this;
     return function() {
       // onStep is called with 'this' set to the current frame.
-
       const location = thread.sources.getFrameLocation(this);
 
-      // Always continue execution if either:
-      //
-      // 1. We are in a source mapped region, but inside a null mapping
-      //    (doesn't correlate to any region of source)
-      // 2. The source we are in is black boxed.
-      if (location.url == null || thread.sources.isBlackBoxed(location.url)) {
+      // Continue if the source is black boxed.
+      if (thread.sources.isBlackBoxed(location.url)) {
         return undefined;
       }
 

devtools/server/tests/unit/test_stepping-11.js

@@ -0,0 +1,30 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+/* eslint-disable no-shadow */
+
+"use strict";
+
+/**
+ * Check basic stepping for console evaluations.
+ */
+
+add_task(
+  threadFrontTest(async ({ threadFront, targetFront, debuggee }) => {
+    dumpn("Evaluating test code and waiting for first debugger statement");
+
+    const consoleFront = await targetFront.getFront("console");
+    consoleFront.evaluateJSAsync(
+      `(function(){
+        debugger;
+        var a = 1;
+        var b = 2;
+      })();`
+    );
+
+    await waitForEvent(threadFront, "paused");
+    await threadFront.stepOver();
+    const packet = await waitForEvent(threadFront, "paused");
+    Assert.equal(packet.frame.where.line, 3, "step to line 3");
+    await threadFront.resume();
+  })
+);

devtools/server/tests/unit/xpcshell.ini

@@ -189,6 +189,7 @@ skip-if = true # breakpoint sliding is not supported bug 1525685
 [test_stepping-08.js]
 [test_stepping-09.js]
 [test_stepping-10.js]
+[test_stepping-11.js]
 [test_stepping-with-skip-breakpoints.js]
 [test_framebindings-01.js]
 [test_framebindings-02.js]