v8/test/mjsunit/es6/debug-stepin-collections-foreach.js

// Copyright 2014 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.
//
// Flags: --expose-debug-as debug

Debug = debug.Debug

var exception = false;

function listener(event, exec_state, event_data, data) {
  try {
    if (event == Debug.DebugEvent.Break) {
      if (breaks == 0) {
        exec_state.prepareStep(Debug.StepAction.StepIn, 2);
        breaks = 1;
      } else if (breaks <= 3) {
        breaks++;
        // Check whether we break at the expected line.
        print(event_data.sourceLineText());
        assertTrue(event_data.sourceLineText().indexOf("Expected to step") > 0);
        exec_state.prepareStep(Debug.StepAction.StepIn, 3);
      }
    }
  } catch (e) {
    exception = true;
  }
}

function cb_set(num) {
  print("element " + num);  // Expected to step to this point.
  return true;
}

function cb_map(key, val) {
  print("key " + key + ", value " + val);  // Expected to step to this point.
  return true;
}

var s = new Set();
s.add(1);
s.add(2);
s.add(3);
s.add(4);

var m = new Map();
m.set('foo', 1);
m.set('bar', 2);
m.set('baz', 3);
m.set('bat', 4);

Debug.setListener(listener);

var breaks = 0;
debugger;
s.forEach(cb_set);
assertFalse(exception);
assertEquals(4, breaks);

breaks = 0;
debugger;
m.forEach(cb_map);
assertFalse(exception);
assertEquals(4, breaks);

Debug.setListener(null);


// Test two levels of builtin callbacks:
// Array.forEach calls a callback function, which by itself uses
// Array.forEach with another callback function.

function second_level_listener(event, exec_state, event_data, data) {
  try {
    if (event == Debug.DebugEvent.Break) {
      if (breaks == 0) {
        exec_state.prepareStep(Debug.StepAction.StepIn, 3);
        breaks = 1;
      } else if (breaks <= 16) {
        breaks++;
        // Check whether we break at the expected line.
        assertTrue(event_data.sourceLineText().indexOf("Expected to step") > 0);
        // Step two steps further every four breaks to skip the
        // forEach call in the first level of recurision.
        var step = (breaks % 4 == 1) ? 6 : 3;
        exec_state.prepareStep(Debug.StepAction.StepIn, step);
      }
    }
  } catch (e) {
    exception = true;
  }
}

function cb_set_foreach(num) {
  s.forEach(cb_set);
  print("back to the first level of recursion.");
}

function cb_map_foreach(key, val) {
  m.forEach(cb_set);
  print("back to the first level of recursion.");
}

Debug.setListener(second_level_listener);

breaks = 0;
debugger;
s.forEach(cb_set_foreach);
assertFalse(exception);
assertEquals(17, breaks);

breaks = 0;
debugger;
m.forEach(cb_map_foreach);
assertFalse(exception);
assertEquals(17, breaks);

Debug.setListener(null);