[debugger] Various break-related functionality in test wrapper

test/debugger/debugger/debug-step.js

Index: test/debugger/debugger/debug-step.js
diff --git a/test/debugger/debugger/debug-step.js b/test/debugger/debugger/debug-step.js
new file mode 100644
index 0000000000000000000000000000000000000000..3560efd1df1c50ac5d1ef0bffa7b667c142229a1
--- /dev/null
+++ b/test/debugger/debugger/debug-step.js
@@ -0,0 +1,43 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+Debug = new DebugWrapper();
+Debug.enable();
+
+// Simple debug event handler which performs 100 steps and then retrieves
+// the resulting value of "i" in f().
+
+function listener(event, exec_state, event_data, data) {
+  if (event == Debug.DebugEvent.Break) {
+    if (step_count > 0) {
+      Debug.stepInto();
+      step_count--;
+    } else {
+      const frameid = exec_state.frames[0].callFrameId;
+      result = Debug.evaluate(frameid, "i").value;
+    }
+  }
+};
+
+// Add the debug event listener.
+Debug.setListener(listener);
+
+// Test debug event for break point.
+function f() {
+  var i;                       // Line 1.
+  for (i = 0; i < 100; i++) {  // Line 2.
+    x = 1;                     // Line 3.
+  }
+};
+
+// Set a breakpoint on the for statement (line 1).
+Debug.setBreakPoint(f, 1);
+
+// Check that performing 100 steps will make i 33.
+let step_count = 100;
+let result = -1;
+
+f();
+
+assertEquals(33, result);