/**
 * @license
 * Copyright 2019 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

goog.module('Blockly.test.event');

const eventUtils = goog.require('Blockly.Events.utils');
const {assertEventEquals, assertNthCallEventArgEquals, assertVariableValues, createFireChangeListenerSpy, createGenUidStubWithReturns, sharedTestSetup, sharedTestTeardown, workspaceTeardown} = goog.require('Blockly.test.helpers');
const {ASTNode} = goog.require('Blockly.ASTNode');
goog.require('Blockly.WorkspaceComment');


suite('Events', function() {
  setup(function() {
    sharedTestSetup.call(this, {fireEventsNow: false});
    this.eventsFireSpy = sinon.spy(eventUtils, 'fire');
    this.workspace = new Blockly.Workspace();
    Blockly.defineBlocksWithJsonArray([{
      'type': 'field_variable_test_block',
      'message0': '%1',
      'args0': [
        {
          'type': 'field_variable',
          'name': 'VAR',
          'variable': 'item'
        }
      ],
    },
    {
      'type': 'simple_test_block',
      'message0': 'simple test block'
    }]);
  });

  teardown(function() {
    sharedTestTeardown.call(this);
  });

  function createSimpleTestBlock(workspace) {
    // Disable events while constructing the block: this is a test of the
    // Blockly.Event constructors, not the block constructors.
    // Set the group id to avoid an extra call to genUid.
    eventUtils.disable();
    let block;
    try {
      eventUtils.setGroup('unused');
      block = new Blockly.Block(
          workspace, 'simple_test_block');
    } finally {
      eventUtils.setGroup(false);
    }
    eventUtils.enable();
    return block;
  }

  suite('Constructors', function() {
    test('Abstract', function() {
      let event = new Blockly.Events.Abstract();
      assertEventEquals(event, undefined, undefined, undefined, {
        'recordUndo': true,
        'group': ''
      });
    });

    test('UI event without block', function() {
      let event = new Blockly.Events.UiBase(this.workspace.id);
      assertEventEquals(event, undefined, this.workspace.id, undefined, {
        'recordUndo': false,
        'group': '',
      }, true);
    });

    test('Click without block', function() {
      let event = new Blockly.Events.Click(null, this.workspace.id, 'workspace');
      assertEventEquals(event, Blockly.Events.CLICK, this.workspace.id, null, {
        'targetType': 'workspace',
        'recordUndo': false,
        'group': ''
      }, true);
    });

    test('Old UI event without block', function() {
      let TEST_GROUP_ID = 'testGroup';
      eventUtils.setGroup(TEST_GROUP_ID);
      let event = new Blockly.Events.Ui(null, 'foo', 'bar', 'baz');
      assertEventEquals(event, Blockly.Events.UI, '', null, {
        'element': 'foo',
        'oldValue': 'bar',
        'newValue': 'baz',
        'recordUndo': false,
        'group': TEST_GROUP_ID
      }, true);
    });

    suite('With simple blocks', function() {
      setup(function() {
        this.TEST_BLOCK_ID = 'test_block_id';
        this.TEST_PARENT_ID = 'parent';
        // genUid is expected to be called either once or twice in this suite.
        this.genUidStub = createGenUidStubWithReturns(
            [this.TEST_BLOCK_ID, this.TEST_PARENT_ID]);
        this.block = createSimpleTestBlock(this.workspace);
      });

      test('Block base', function() {
        let event = new Blockly.Events.BlockBase(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, undefined,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'varId': undefined,
              'recordUndo': true,
              'group': '',
            });
      });

      test('Block create', function() {
        let event = new Blockly.Events.BlockCreate(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.BLOCK_CREATE,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'recordUndo': true,
              'group': '',
            });
      });

      test('Block delete', function() {
        let event = new Blockly.Events.BlockDelete(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.BLOCK_DELETE,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'recordUndo': true,
              'group': '',
            });
      });

      test('Old UI event with block', function() {
        let TEST_GROUP_ID = 'testGroup';
        eventUtils.setGroup(TEST_GROUP_ID);
        let event = new Blockly.Events.Ui(this.block, 'foo', 'bar', 'baz');
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.UI, this.workspace.id,
            this.TEST_BLOCK_ID,
            {
              'element': 'foo',
              'oldValue': 'bar',
              'newValue': 'baz',
              'recordUndo': false,
              'group': TEST_GROUP_ID
            }, true);
      });

      test('Click with block', function() {
        let TEST_GROUP_ID = 'testGroup';
        eventUtils.setGroup(TEST_GROUP_ID);
        let event = new Blockly.Events.Click(this.block, null, 'block');
        assertEventEquals(event, Blockly.Events.CLICK, this.workspace.id,
            this.TEST_BLOCK_ID, {
              'targetType': 'block',
              'recordUndo': false,
              'group': TEST_GROUP_ID
            }, true);
      });

      suite('Block Move', function() {
        test('by coordinate', function() {
          let coordinate = new Blockly.utils.Coordinate(3, 4);
          this.block.xy_ = coordinate;

          let event = new Blockly.Events.BlockMove(this.block);
          sinon.assert.calledOnce(this.genUidStub);
          assertEventEquals(event, Blockly.Events.BLOCK_MOVE, this.workspace.id,
              this.TEST_BLOCK_ID, {
                'oldParentId': undefined,
                'oldInputName': undefined,
                'oldCoordinate': coordinate,
                'recordUndo': true,
                'group': ''
              });
        });

        test('by parent', function() {
          try {
            this.parentBlock = createSimpleTestBlock(this.workspace);
            this.block.parentBlock_ = this.parentBlock;
            this.block.xy_ = new Blockly.utils.Coordinate(3, 4);
            let event = new Blockly.Events.BlockMove(this.block);
            sinon.assert.calledTwice(this.genUidStub);
            assertEventEquals(event, Blockly.Events.BLOCK_MOVE, this.workspace.id,
                this.TEST_BLOCK_ID, {
                  'oldParentId': this.TEST_PARENT_ID,
                  'oldInputName': undefined,
                  'oldCoordinate': undefined,
                  'recordUndo': true,
                  'group': ''
                });
          } finally {
            // This needs to be cleared, otherwise workspace.dispose will fail.
            this.block.parentBlock_ = null;
          }
        });
      });
    });

    suite('With shadow blocks', function() {
      setup(function() {
        this.TEST_BLOCK_ID = 'test_block_id';
        this.TEST_PARENT_ID = 'parent';
        // genUid is expected to be called either once or twice in this suite.
        this.genUidStub = createGenUidStubWithReturns(
            [this.TEST_BLOCK_ID, this.TEST_PARENT_ID]);
        this.block = createSimpleTestBlock(this.workspace);
        this.block.setShadow(true);
      });

      test('Block base', function() {
        let event = new Blockly.Events.BlockBase(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, undefined,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'varId': undefined,
              'recordUndo': true,
              'group': '',
            });
      });

      test('Block change', function() {
        let event = new Blockly.Events.BlockChange(
            this.block, 'field', 'FIELD_NAME', 'old', 'new');
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.BLOCK_CHANGE,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'varId': undefined,
              'element': 'field',
              'name': 'FIELD_NAME',
              'oldValue': 'old',
              'newValue': 'new',
              'recordUndo': true,
              'group': '',
            });
      });

      test('Block create', function() {
        let event = new Blockly.Events.BlockCreate(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.BLOCK_CREATE,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'recordUndo': false,
              'group': '',
            });
      });

      test('Block delete', function() {
        let event = new Blockly.Events.BlockDelete(this.block);
        sinon.assert.calledOnce(this.genUidStub);
        assertEventEquals(event, Blockly.Events.BLOCK_DELETE,
            this.workspace.id, this.TEST_BLOCK_ID,
            {
              'recordUndo': false,
              'group': '',
            });
      });

      test('Block move', function() {
        try {
          this.parentBlock = createSimpleTestBlock(this.workspace);
          this.block.parentBlock_ = this.parentBlock;
          this.block.xy_ = new Blockly.utils.Coordinate(3, 4);
          let event = new Blockly.Events.BlockMove(this.block);
          sinon.assert.calledTwice(this.genUidStub);
          assertEventEquals(event, Blockly.Events.BLOCK_MOVE, this.workspace.id,
              this.TEST_BLOCK_ID,
              {
                'oldParentId': this.TEST_PARENT_ID,
                'oldInputName': undefined,
                'oldCoordinate': undefined,
                'recordUndo': false,
                'group': ''
              });
        } finally {
          // This needs to be cleared, otherwise workspace.dispose will fail.
          this.block.parentBlock_ = null;
        }
      });
    });

    suite('With variable getter blocks', function() {
      setup(function() {
        this.genUidStub = createGenUidStubWithReturns(
            [this.TEST_BLOCK_ID, 'test_var_id', 'test_group_id']);
        // Disabling events when creating a block with variable can cause issues
        // at workspace dispose.
        this.block = new Blockly.Block(
            this.workspace, 'field_variable_test_block');
      });

      test('Block change', function() {
        let event = new Blockly.Events.BlockChange(
            this.block, 'field', 'VAR', 'id1', 'id2');
        assertEventEquals(event, Blockly.Events.BLOCK_CHANGE, this.workspace.id,
            this.TEST_BLOCK_ID,
            {
              'element': 'field',
              'name': 'VAR',
              'oldValue': 'id1',
              'newValue': 'id2',
              'recordUndo': true,
              'group': ''
            });
      });
    });
  });

  suite('Serialization', function() {
    let safeStringify = (json) => {
      let cache = [];
      return JSON.stringify(json, (key, value) => {
        if (typeof value == 'object' && value != null) {
          if (cache.includes(value)) {
            // Discard duplicate reference.
            return undefined;
          }
          cache.push(value);
          return value;
        }
        return value;
      });
    };
    let variableEventTestCases = [
      {title: 'Var create', class: Blockly.Events.VarCreate,
        getArgs: (thisObj) => [thisObj.variable],
        getExpectedJson: () => ({type: 'var_create', varId: 'id1',
          varType: 'type1', varName: 'name1'})},
      {title: 'Var delete', class: Blockly.Events.VarDelete,
        getArgs: (thisObj) => [thisObj.variable],
        getExpectedJson: () => ({type: 'var_delete', varId: 'id1',
          varType: 'type1', varName: 'name1'})},
      {title: 'Var rename', class: Blockly.Events.VarRename,
        getArgs: (thisObj) => [thisObj.variable, 'name2'],
        getExpectedJson: () => ({type: 'var_rename', varId: 'id1',
          oldName: 'name1', newName: 'name2'})},
    ];
    let uiEventTestCases = [
      {title: 'Bubble open', class: Blockly.Events.BubbleOpen,
        getArgs: (thisObj) => [thisObj.block, true, 'mutator'],
        getExpectedJson: (thisObj) => ({type: 'bubble_open', isOpen: true,
          bubbleType: 'mutator', blockId: thisObj.block.id})},
      {title: 'Block click', class: Blockly.Events.Click,
        getArgs: (thisObj) => [thisObj.block, null, 'block'],
        getExpectedJson: (thisObj) => ({type: 'click', targetType: 'block',
          blockId: thisObj.block.id})},
      {title: 'Workspace click', class: Blockly.Events.Click,
        getArgs: (thisObj) => [null, thisObj.workspace.id, 'workspace'],
        getExpectedJson: (thisObj) => ({type: 'click',
          targetType: 'workspace'})},
      {title: 'Drag start', class: Blockly.Events.BlockDrag,
        getArgs: (thisObj) => [thisObj.block, true, [thisObj.block]],
        getExpectedJson: (thisObj) => ({type: 'drag',
          isStart: true, blockId: thisObj.block.id, blocks: [thisObj.block]})},
      {title: 'Drag end', class: Blockly.Events.BlockDrag,
        getArgs: (thisObj) => [thisObj.block, false, [thisObj.block]],
        getExpectedJson: (thisObj) => ({type: 'drag',
          isStart: false, blockId: thisObj.block.id, blocks: [thisObj.block]})},
      {title: 'null to Block Marker move', class: Blockly.Events.MarkerMove,
        getArgs: (thisObj) => [thisObj.block, true, null,
          new ASTNode(ASTNode.types.BLOCK, thisObj.block)],
        getExpectedJson: (thisObj) => ({type: 'marker_move',
          isCursor: true, blockId: thisObj.block.id, oldNode: null,
          newNode: new ASTNode(ASTNode.types.BLOCK,
              thisObj.block)})},
      {title: 'null to Workspace Marker move', class: Blockly.Events.MarkerMove,
        getArgs: (thisObj) => [null, true, null,
          ASTNode.createWorkspaceNode(thisObj.workspace,
              new Blockly.utils.Coordinate(0, 0))],
        getExpectedJson: (thisObj) => ({type: 'marker_move',
          isCursor: true, blockId: null, oldNode: null,
          newNode: ASTNode.createWorkspaceNode(thisObj.workspace,
              new Blockly.utils.Coordinate(0, 0))})},
      {title: 'Workspace to Block Marker move',
        class: Blockly.Events.MarkerMove,
        getArgs: (thisObj) => [thisObj.block, true,
          ASTNode.createWorkspaceNode(thisObj.workspace,
              new Blockly.utils.Coordinate(0, 0)),
          new ASTNode(ASTNode.types.BLOCK, thisObj.block)],
        getExpectedJson: (thisObj) => ({type: 'marker_move',
          isCursor: true, blockId: thisObj.block.id,
          oldNode: ASTNode.createWorkspaceNode(thisObj.workspace,
              new Blockly.utils.Coordinate(0, 0)),
          newNode: new ASTNode(ASTNode.types.BLOCK,
              thisObj.block)})},
      {title: 'Block to Workspace Marker move',
        class: Blockly.Events.MarkerMove,
        getArgs: (thisObj) => [null, true,
          new ASTNode(ASTNode.types.BLOCK, thisObj.block),
          ASTNode.createWorkspaceNode(thisObj.workspace,
              new Blockly.utils.Coordinate(0, 0))]},
      {title: 'Selected', class: Blockly.Events.Selected,
        getArgs: (thisObj) => [null, thisObj.block.id, thisObj.workspace.id],
        getExpectedJson: (thisObj) => ({type: 'selected', oldElementId: null,
          newElementId: thisObj.block.id})},
      {title: 'Selected (deselect)', class: Blockly.Events.Selected,
        getArgs: (thisObj) => [thisObj.block.id, null, thisObj.workspace.id],
        getExpectedJson: (thisObj) => ({type: 'selected',
          oldElementId: thisObj.block.id, newElementId: null})},
      {title: 'Theme Change', class: Blockly.Events.ThemeChange,
        getArgs: (thisObj) => ['classic', thisObj.workspace.id],
        getExpectedJson: () => ({type: 'theme_change', themeName: 'classic'})},
      {title: 'Toolbox item select',
        class: Blockly.Events.ToolboxItemSelect,
        getArgs: (thisObj) => ['Math', 'Loops', thisObj.workspace.id],
        getExpectedJson: () => ({type: 'toolbox_item_select', oldItem: 'Math',
          newItem: 'Loops'})},
      {title: 'Toolbox item select (no previous)',
        class: Blockly.Events.ToolboxItemSelect,
        getArgs: (thisObj) => [null, 'Loops', thisObj.workspace.id],
        getExpectedJson: () => ({type: 'toolbox_item_select', oldItem: null,
          newItem: 'Loops'})},
      {title: 'Toolbox item select (deselect)',
        class: Blockly.Events.ToolboxItemSelect,
        getArgs: (thisObj) => ['Math', null, thisObj.workspace.id],
        getExpectedJson: () => ({type: 'toolbox_item_select', oldItem: 'Math',
          newItem: null})},
      {title: 'Trashcan open', class: Blockly.Events.TrashcanOpen,
        getArgs: (thisObj) => [true, thisObj.workspace.id],
        getExpectedJson: () => ({type: 'trashcan_open', isOpen: true})},
      {title: 'Viewport change', class: Blockly.Events.ViewportChange,
        getArgs: (thisObj) => [2.666, 1.333, 1.2, thisObj.workspace.id, 1],
        getExpectedJson: () => ({type: 'viewport_change', viewTop: 2.666,
          viewLeft: 1.333, scale: 1.2, oldScale: 1})},
      {title: 'Viewport change (0,0)', class: Blockly.Events.ViewportChange,
        getArgs: (thisObj) => [0, 0, 1.2, thisObj.workspace.id, 1],
        getExpectedJson: () => ({type: 'viewport_change', viewTop: 0,
          viewLeft: 0, scale: 1.2, oldScale: 1})},
    ];
    let blockEventTestCases = [
      {
        title: 'Block change',
        class: Blockly.Events.BlockChange,
        getArgs: (thisObj) => [thisObj.block, 'collapsed', null, false, true],
        getExpectedJson: (thisObj) => ({
          type: 'change',
          blockId: thisObj.block.id,
          element: 'collapsed',
          oldValue: false,
          newValue: true
        })
      },
      {
        title: 'Block create',
        class: Blockly.Events.BlockCreate,
        getArgs: (thisObj) => [thisObj.block],
        getExpectedJson: (thisObj) => ({
          type: 'create',
          blockId: thisObj.block.id,
          xml: '<block xmlns="https://developers.google.com/blockly/xml"' +
              ' type="simple_test_block" id="testBlockId1" x="0" y="0">' +
              '</block>',
          ids: [thisObj.block.id],
          json: {
            'type': 'simple_test_block',
            'id': 'testBlockId1',
            'x': 0,
            'y': 0,
          },
        })
      },
      {
        title: 'Block create (shadow)',
        class: Blockly.Events.BlockCreate,
        getArgs: (thisObj) => [thisObj.shadowBlock],
        getExpectedJson: (thisObj) => ({
          type: 'create',
          blockId: thisObj.shadowBlock.id,
          xml: '<shadow xmlns="https://developers.google.com/blockly/xml"' +
              ' type="simple_test_block" id="testBlockId2" x="0" y="0">' +
              '</shadow>',
          ids: [thisObj.shadowBlock.id],
          json: {
            'type': 'simple_test_block',
            'id': 'testBlockId2',
            'x': 0,
            'y': 0,
          },
          recordUndo: false
        })
      },
      {
        title: 'Block delete',
        class: Blockly.Events.BlockDelete,
        getArgs: (thisObj) => [thisObj.block],
        getExpectedJson: (thisObj) => ({
          type: 'delete',
          blockId: thisObj.block.id,
          oldXml: '<block xmlns="https://developers.google.com/blockly/xml"' +
              ' type="simple_test_block" id="testBlockId1" x="0" y="0">' +
              '</block>',
          ids: [thisObj.block.id],
          wasShadow: false,
          oldJson: {
            'type': 'simple_test_block',
            'id': 'testBlockId1',
            'x': 0,
            'y': 0,
          },
        })
      },
      {
        title: 'Block delete (shadow)',
        class: Blockly.Events.BlockDelete,
        getArgs: (thisObj) => [thisObj.shadowBlock],
        getExpectedJson: (thisObj) => ({
          type: 'delete',
          blockId: thisObj.shadowBlock.id,
          oldXml: '<shadow xmlns="https://developers.google.com/blockly/xml"' +
              ' type="simple_test_block" id="testBlockId2" x="0" y="0">' +
              '</shadow>',
          ids: [thisObj.shadowBlock.id],
          wasShadow: true,
          oldJson: {
            'type': 'simple_test_block',
            'id': 'testBlockId2',
            'x': 0,
            'y': 0,
          },
          recordUndo: false
        })
      },
      // TODO(#4577) Test serialization of move event coordinate properties.
      {
        title: 'Block move',
        class: Blockly.Events.BlockMove,
        getArgs: (thisObj) => [thisObj.block],
        getExpectedJson: (thisObj) => ({
          type: 'move',
          blockId: thisObj.block.id
        })
      },
      {
        title: 'Block move (shadow)',
        class: Blockly.Events.BlockMove,
        getArgs: (thisObj) => [thisObj.shadowBlock],
        getExpectedJson: (thisObj) => ({
          type: 'move',
          blockId: thisObj.shadowBlock.id,
          recordUndo: false
        })
      },
    ];
    let workspaceEventTestCases = [
      {title: 'Finished Loading', class: Blockly.Events.FinishedLoading,
        getArgs: (thisObj) => [thisObj.workspace],
        getExpectedJson: (thisObj) => ({type: 'finished_loading',
          workspaceId: thisObj.workspace.id})},
    ];
    let workspaceCommentEventTestCases = [
      {title: 'Comment change', class: Blockly.Events.CommentChange,
        getArgs: (thisObj) => [thisObj.comment, 'bar', 'foo'],
        getExpectedJson: (thisObj) => ({type: 'comment_change',
          commentId: thisObj.comment.id, oldContents: 'bar',
          newContents: 'foo'})},
      {title: 'Comment create', class: Blockly.Events.CommentCreate,
        getArgs: (thisObj) => [thisObj.comment],
        getExpectedJson: (thisObj) => ({type: 'comment_create',
          commentId: thisObj.comment.id,
          xml: Blockly.Xml.domToText(thisObj.comment.toXmlWithXY())})},
      {title: 'Comment delete', class: Blockly.Events.CommentDelete,
        getArgs: (thisObj) => [thisObj.comment],
        getExpectedJson: (thisObj) => ({type: 'comment_delete',
          commentId: thisObj.comment.id})},
      // TODO(#4577) Test serialization of move event coordinate properties.
      {title: 'Comment move', class: Blockly.Events.CommentMove,
        getArgs: (thisObj) => [thisObj.comment],
        getExpectedJson: (thisObj) => ({type: 'comment_move',
          commentId: thisObj.comment.id, oldCoordinate: '0,0'})},
    ];
    let testSuites = [
      {title: 'Variable events', testCases: variableEventTestCases,
        setup: (thisObj) => {
          thisObj.variable =
              thisObj.workspace.createVariable('name1', 'type1', 'id1');
        }},
      {title: 'UI events', testCases: uiEventTestCases,
        setup: (thisObj) => {
          thisObj.block = createSimpleTestBlock(thisObj.workspace);
        }},
      {title: 'Block events', testCases: blockEventTestCases,
        setup: (thisObj) => {
          createGenUidStubWithReturns(['testBlockId1', 'testBlockId2']);
          thisObj.block = createSimpleTestBlock(thisObj.workspace);
          thisObj.shadowBlock = createSimpleTestBlock(thisObj.workspace);
          thisObj.shadowBlock.setShadow(true);
        }},
      {title: 'Workspace events',
        testCases: workspaceEventTestCases,
        setup: (_) => {}},
      {title: 'WorkspaceComment events',
        testCases: workspaceCommentEventTestCases,
        setup: (thisObj) => {
          thisObj.comment = new Blockly.WorkspaceComment(
              thisObj.workspace, 'comment text', 0, 0, 'comment id');
        }},
    ];
    testSuites.forEach((testSuite) => {
      suite(testSuite.title, function() {
        setup(function() {
          testSuite.setup(this);
        });
        suite('fromJson', function() {
          testSuite.testCases.forEach((testCase) => {
            test(testCase.title, function() {
              let event = new testCase.class(...testCase.getArgs(this));
              let event2 = new testCase.class();
              let json = event.toJson();
              event2.fromJson(json);

              chai.assert.equal(
                  safeStringify(event2.toJson()), safeStringify(json));
            });
          });
        });
        suite('toJson', function() {
          testSuite.testCases.forEach((testCase) => {
            if (testCase.getExpectedJson) {
              test(testCase.title, function() {
                let event = new testCase.class(...testCase.getArgs(this));
                let json = event.toJson();
                let expectedJson = testCase.getExpectedJson(this);

                chai.assert.equal(
                    safeStringify(json), safeStringify(expectedJson));
              });
            }
          });
        });
      });
    });
  });

  suite('Variable events', function() {
    setup(function() {
      this.variable = this.workspace.createVariable('name1', 'type1', 'id1');
    });

    /**
     * Check if a variable with the given values exists.
     * @param {Blockly.Workspace|Blockly.VariableMap} container The workspace  or
     *     variableMap the checked variable belongs to.
     * @param {!string} name The expected name of the variable.
     * @param {!string} type The expected type of the variable.
     * @param {!string} id The expected id of the variable.
     */
    function checkVariableValues(container, name, type, id) {
      let variable = container.getVariableById(id);
      chai.assert.isDefined(variable);
      chai.assert.equal(name, variable.name);
      chai.assert.equal(type, variable.type);
      chai.assert.equal(id, variable.getId());
    }

    suite('Constructors', function() {
      test('Var base', function() {
        let event = new Blockly.Events.VarBase(this.variable);
        assertEventEquals(event, undefined, this.workspace.id, undefined, {
          'varId': 'id1',
          'recordUndo': true,
          'group': ''
        });
      });

      test('Var create', function() {
        let event = new Blockly.Events.VarCreate(this.variable);
        assertEventEquals(event, Blockly.Events.VAR_CREATE, this.workspace.id,
            undefined,
            {
              'varId': 'id1',
              'varType': 'type1',
              'varName': 'name1',
              'recordUndo': true,
              'group': ''
            });
      });

      test('Var delete', function() {
        let event = new Blockly.Events.VarDelete(this.variable);
        assertEventEquals(event, Blockly.Events.VAR_DELETE, this.workspace.id,
            undefined,
            {
              'varId': 'id1',
              'varType': 'type1',
              'varName': 'name1',
              'recordUndo': true,
              'group': ''
            });
      });

      test('Var rename', function() {
        let event = new Blockly.Events.VarRename(this.variable, 'name2');
        assertEventEquals(event, Blockly.Events.VAR_RENAME, this.workspace.id,
            undefined,
            {
              'varId': 'id1',
              'oldName': 'name1',
              'newName': 'name2',
              'recordUndo': true,
              'group': ''
            });
      });
    });

    suite('Run Forward', function() {
      test('Var create', function() {
        let json = {type: "var_create", varId: "id2", varType: "type2",
          varName: "name2"};
        let event = eventUtils.fromJson(json, this.workspace);
        let x = this.workspace.getVariableById('id2');
        chai.assert.isNull(x);
        event.run(true);
        assertVariableValues(this.workspace, 'name2', 'type2', 'id2');
      });

      test('Var delete', function() {
        let event = new Blockly.Events.VarDelete(this.variable);
        chai.assert.isNotNull(this.workspace.getVariableById('id1'));
        event.run(true);
        chai.assert.isNull(this.workspace.getVariableById('id1'));
      });

      test('Var rename', function() {
        let event = new Blockly.Events.VarRename(this.variable, 'name2');
        event.run(true);
        chai.assert.isNull(this.workspace.getVariable('name1'));
        checkVariableValues(this.workspace, 'name2', 'type1', 'id1');
      });
    });
    suite('Run Backward', function() {
      test('Var create', function() {
        let event = new Blockly.Events.VarCreate(this.variable);
        chai.assert.isNotNull(this.workspace.getVariableById('id1'));
        event.run(false);
      });

      test('Var delete', function() {
        let json = {type: "var_delete", varId: "id2", varType: "type2",
          varName: "name2"};
        let event = eventUtils.fromJson(json, this.workspace);
        chai.assert.isNull(this.workspace.getVariableById('id2'));
        event.run(false);
        assertVariableValues(this.workspace, 'name2', 'type2', 'id2');
      });

      test('Var rename', function() {
        let event = new Blockly.Events.VarRename(this.variable, 'name2');
        event.run(false);
        chai.assert.isNull(this.workspace.getVariable('name2'));
        checkVariableValues(this.workspace, 'name1', 'type1', 'id1');
      });
    });
  });

  suite('Filters', function() {
    function addMoveEvent(events, block, newX, newY) {
      events.push(new Blockly.Events.BlockMove(block));
      block.xy_ = new Blockly.utils.Coordinate(newX, newY);
      events[events.length - 1].recordNew();
    }

    function addMoveEventParent(events, block, parent) {
      events.push(new Blockly.Events.BlockMove(block));
      block.setParent(parent);
      events[events.length - 1].recordNew();
    }

    test('No removed, order unchanged', function() {
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [
        new Blockly.Events.BlockCreate(block),
        new Blockly.Events.BlockMove(block),
        new Blockly.Events.BlockChange(block, 'field', 'VAR', 'id1', 'id2'),
        new Blockly.Events.Click(block)
      ];
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 4);  // no event should have been removed.
      // test that the order hasn't changed
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.BlockCreate);
      chai.assert.isTrue(filteredEvents[1] instanceof Blockly.Events.BlockMove);
      chai.assert.isTrue(filteredEvents[2] instanceof Blockly.Events.BlockChange);
      chai.assert.isTrue(filteredEvents[3] instanceof Blockly.Events.Click);
    });

    test('Different blocks no removed', function() {
      let block1 = this.workspace.newBlock('field_variable_test_block', '1');
      let block2 = this.workspace.newBlock('field_variable_test_block', '2');
      let events = [
        new Blockly.Events.BlockCreate(block1),
        new Blockly.Events.BlockMove(block1),
        new Blockly.Events.BlockCreate(block2),
        new Blockly.Events.BlockMove(block2)
      ];
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 4);  // no event should have been removed.
    });

    test('Forward', function() {
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [ new Blockly.Events.BlockCreate(block) ];
      addMoveEvent(events, block, 1, 1);
      addMoveEvent(events, block, 2, 2);
      addMoveEvent(events, block, 3, 3);
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 2);  // duplicate moves should have been removed.
      // test that the order hasn't changed
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.BlockCreate);
      chai.assert.isTrue(filteredEvents[1] instanceof Blockly.Events.BlockMove);
      chai.assert.equal(filteredEvents[1].newCoordinate.x, 3);
      chai.assert.equal(filteredEvents[1].newCoordinate.y, 3);
    });

    test('Backward', function() {
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [ new Blockly.Events.BlockCreate(block) ];
      addMoveEvent(events, block, 1, 1);
      addMoveEvent(events, block, 2, 2);
      addMoveEvent(events, block, 3, 3);
      let filteredEvents = eventUtils.filter(events, false);
      chai.assert.equal(filteredEvents.length, 2);  // duplicate event should have been removed.
      // test that the order hasn't changed
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.BlockCreate);
      chai.assert.isTrue(filteredEvents[1] instanceof Blockly.Events.BlockMove);
      chai.assert.equal(filteredEvents[1].newCoordinate.x, 1);
      chai.assert.equal(filteredEvents[1].newCoordinate.y, 1);
    });

    test('Merge block move events', function() {
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [];
      addMoveEvent(events, block, 0, 0);
      addMoveEvent(events, block, 1, 1);
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 1);  // second move event merged into first
      chai.assert.equal(filteredEvents[0].newCoordinate.x, 1);
      chai.assert.equal(filteredEvents[0].newCoordinate.y, 1);
    });

    test('Merge block change events', function() {
      let block1 = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [
        new Blockly.Events.BlockChange(block1, 'field', 'VAR', 'item', 'item1'),
        new Blockly.Events.BlockChange(block1, 'field', 'VAR', 'item1', 'item2')
      ];
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 1);  // second change event merged into first
      chai.assert.equal(filteredEvents[0].oldValue, 'item');
      chai.assert.equal(filteredEvents[0].newValue, 'item2');
    });

    test('Merge viewport change events', function() {
      let events = [
        new Blockly.Events.ViewportChange(1, 2, 3, this.workspace, 4),
        new Blockly.Events.ViewportChange(5, 6, 7, this.workspace, 8)
      ];
      let filteredEvents = eventUtils.filter(events, true);
      chai.assert.equal(filteredEvents.length, 1);  // second change event merged into first
      chai.assert.equal(filteredEvents[0].viewTop, 5);
      chai.assert.equal(filteredEvents[0].viewLeft, 6);
      chai.assert.equal(filteredEvents[0].scale, 7);
      chai.assert.equal(filteredEvents[0].oldScale, 8);
    });

    test('Merge ui events', function() {
      let block1 = this.workspace.newBlock('field_variable_test_block', '1');
      let block2 = this.workspace.newBlock('field_variable_test_block', '2');
      let block3 = this.workspace.newBlock('field_variable_test_block', '3');
      let events = [
        new Blockly.Events.BubbleOpen(block1, true, 'comment'),
        new Blockly.Events.Click(block1),
        new Blockly.Events.BubbleOpen(block2, true, 'mutator'),
        new Blockly.Events.Click(block2),
        new Blockly.Events.BubbleOpen(block3, true, 'warning'),
        new Blockly.Events.Click(block3)
      ];
      let filteredEvents = eventUtils.filter(events, true);
      // click event merged into corresponding *Open event
      chai.assert.equal(filteredEvents.length, 3);
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.BubbleOpen);
      chai.assert.isTrue(filteredEvents[1] instanceof Blockly.Events.BubbleOpen);
      chai.assert.isTrue(filteredEvents[2] instanceof Blockly.Events.BubbleOpen);
      chai.assert.equal(filteredEvents[0].bubbleType, 'comment');
      chai.assert.equal(filteredEvents[1].bubbleType, 'mutator');
      chai.assert.equal(filteredEvents[2].bubbleType, 'warning');
    });

    test('Colliding events not dropped', function() {
      // Tests that events that collide on a (event, block, workspace) tuple
      // but cannot be merged do not get dropped during filtering.
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      let events = [
        new Blockly.Events.Click(block),
        new Blockly.Events.Ui(block, 'stackclick', undefined, undefined)
      ];
      let filteredEvents = eventUtils.filter(events, true);
      // click and stackclick should both exist
      chai.assert.equal(filteredEvents.length, 2);
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.Click);
      chai.assert.equal(filteredEvents[1].element, 'stackclick');
    });

    test('Merging null operations dropped', function() {
      // Mutator composition could result in move events for blocks
      // connected to the mutated block that were null operations. This
      // leads to events in the undo/redo queue that do nothing, requiring
      // an extra undo/redo to proceed to the next event. This test ensures
      // that two move events that do get merged (disconnecting and
      // reconnecting a block in response to a mutator change) are filtered
      // from the queue.
      let block = this.workspace.newBlock('field_variable_test_block', '1');
      block.setParent(null);
      let events = [];
      addMoveEventParent(events, block, null);
      addMoveEventParent(events, block, null);
      let filteredEvents = eventUtils.filter(events, true);
      // The two events should be merged, but because nothing has changed
      // they will be filtered out.
      chai.assert.equal(filteredEvents.length, 0);
    });

    test('Move events different blocks not merged', function() {
      // Move events should only merge if they refer to the same block and are
      // consecutive.
      // See github.com/google/blockly/pull/1892 for a worked example showing
      // how merging non-consecutive events can fail when replacing a shadow
      // block.
      let block1 = createSimpleTestBlock(this.workspace);
      let block2 = createSimpleTestBlock(this.workspace);

      let events = [];
      addMoveEvent(events, block1, 1, 1);
      addMoveEvent(events, block2, 1, 1);
      events.push(new Blockly.Events.BlockDelete(block2));
      addMoveEvent(events, block1, 2, 2);

      let filteredEvents = eventUtils.filter(events, true);
      // Nothing should have merged.
      chai.assert.equal(filteredEvents.length, 4);
      // test that the order hasn't changed
      chai.assert.isTrue(filteredEvents[0] instanceof Blockly.Events.BlockMove);
      chai.assert.isTrue(filteredEvents[1] instanceof Blockly.Events.BlockMove);
      chai.assert.isTrue(filteredEvents[2] instanceof Blockly.Events.BlockDelete);
      chai.assert.isTrue(filteredEvents[3] instanceof Blockly.Events.BlockMove);
    });
  });

  suite('Firing', function() {
    setup(function() {
      this.changeListenerSpy = createFireChangeListenerSpy(this.workspace);
    });

    test('Block dispose triggers Delete', function() {
      let workspaceSvg;
      try {
        let toolbox = document.getElementById('toolbox-categories');
        workspaceSvg = Blockly.inject('blocklyDiv', {toolbox: toolbox});
        let TEST_BLOCK_ID = 'test_block_id';
        let genUidStub = createGenUidStubWithReturns(
            [TEST_BLOCK_ID, 'test_group_id']);

        let block = workspaceSvg.newBlock('');
        block.initSvg();
        block.setCommentText('test comment');
        let expectedOldXml = Blockly.Xml.blockToDomWithXY(block);
        let expectedId = block.id;

        // Run all queued events.
        this.clock.runAll();

        this.eventsFireSpy.resetHistory();
        let changeListenerSpy = createFireChangeListenerSpy(workspaceSvg);
        block.dispose();

        // Run all queued events.
        this.clock.runAll();

        // Expect two calls to genUid: one to set the block's ID, and one for
        // the event group's ID for creating block.
        sinon.assert.calledTwice(genUidStub);

        assertNthCallEventArgEquals(
            this.eventsFireSpy, 0, Blockly.Events.BlockDelete,
            {oldXml: expectedOldXml, group: ''},
            workspaceSvg.id, expectedId);
        assertNthCallEventArgEquals(
            changeListenerSpy, 0, Blockly.Events.BlockDelete,
            {oldXml: expectedOldXml, group: ''},
            workspaceSvg.id, expectedId);

        // Expect the workspace to not have a variable with ID 'test_block_id'.
        chai.assert.isNull(this.workspace.getVariableById(TEST_BLOCK_ID));
      } finally {
        workspaceTeardown.call(this, workspaceSvg);
      }
    });

    test('New block new var', function() {
      let TEST_BLOCK_ID = 'test_block_id';
      let TEST_GROUP_ID = 'test_group_id';
      let TEST_VAR_ID = 'test_var_id';
      let genUidStub = createGenUidStubWithReturns(
          [TEST_BLOCK_ID, TEST_GROUP_ID, TEST_VAR_ID]);
      let _ = this.workspace.newBlock('field_variable_test_block');
      let TEST_VAR_NAME = 'item';  //  As defined in block's json.

      // Run all queued events.
      this.clock.runAll();

      // Expect three calls to genUid: one to set the block's ID, one for the event
      // group's ID, and one for the variable's ID.
      sinon.assert.calledThrice(genUidStub);

      // Expect two events fired: varCreate and block create.
      sinon.assert.calledTwice(this.eventsFireSpy);
      // Expect both events to trigger change listener.
      sinon.assert.calledTwice(this.changeListenerSpy);
      // Both events should be on undo stack
      chai.assert.equal(this.workspace.undoStack_.length, 2,
          'Undo stack length');

      assertNthCallEventArgEquals(
          this.changeListenerSpy, 0, Blockly.Events.VarCreate,
          {group: TEST_GROUP_ID, varId: TEST_VAR_ID, varName: TEST_VAR_NAME},
          this.workspace.id, undefined);
      assertNthCallEventArgEquals(
          this.changeListenerSpy, 1, Blockly.Events.BlockCreate,
          {group: TEST_GROUP_ID}, this.workspace.id, TEST_BLOCK_ID);

      // Expect the workspace to have a variable with ID 'test_var_id'.
      chai.assert.isNotNull(this.workspace.getVariableById(TEST_VAR_ID));
    });

    test('New block new var xml', function() {
      let TEST_GROUP_ID = 'test_group_id';
      let genUidStub = createGenUidStubWithReturns(TEST_GROUP_ID);
      let dom = Blockly.Xml.textToDom(
          '<xml xmlns="https://developers.google.com/blockly/xml">' +
          '  <block type="field_variable_test_block" id="test_block_id">' +
          '    <field name="VAR" id="test_var_id">name1</field>' +
          '  </block>' +
          '</xml>');
      Blockly.Xml.domToWorkspace(dom, this.workspace);
      let TEST_BLOCK_ID = 'test_block_id';
      let TEST_VAR_ID = 'test_var_id';
      let TEST_VAR_NAME = 'name1';

      // Run all queued events.
      this.clock.runAll();

      // Expect one call to genUid: for the event group's id
      sinon.assert.calledOnce(genUidStub);

      // When block is created using domToWorkspace, 5 events are fired:
      // 1. varCreate (events disabled)
      // 2. varCreate
      // 3. block create
      // 4. move (no-op, is filtered out)
      // 5. finished loading
      sinon.assert.callCount(this.eventsFireSpy, 5);
      // The first varCreate and move event should have been ignored.
      sinon.assert.callCount(this.changeListenerSpy, 3);
      // Expect two events on undo stack: varCreate and block create.
      chai.assert.equal(this.workspace.undoStack_.length, 2,
          'Undo stack length');

      assertNthCallEventArgEquals(
          this.changeListenerSpy, 0, Blockly.Events.VarCreate,
          {group: TEST_GROUP_ID, varId: TEST_VAR_ID, varName: TEST_VAR_NAME},
          this.workspace.id, undefined);
      assertNthCallEventArgEquals(
          this.changeListenerSpy, 1, Blockly.Events.BlockCreate,
          {group: TEST_GROUP_ID}, this.workspace.id, TEST_BLOCK_ID);

      // Finished loading event should not be part of event group.
      assertNthCallEventArgEquals(
          this.changeListenerSpy, 2, Blockly.Events.FinishedLoading,
          {group: ''}, this.workspace.id, undefined);

      // Expect the workspace to have a variable with ID 'test_var_id'.
      chai.assert.isNotNull(this.workspace.getVariableById(TEST_VAR_ID));
    });
  });
  suite('Disable orphans', function() {
    setup(function() {
      // disableOrphans needs a WorkspaceSVG
      let toolbox = document.getElementById('toolbox-categories');
      this.workspace = Blockly.inject('blocklyDiv', {toolbox: toolbox});
    });
    teardown(function() {
      workspaceTeardown.call(this, this.workspace);
    });
    test('Created orphan block is disabled', function() {
      this.workspace.addChangeListener(eventUtils.disableOrphans);
      let block = this.workspace.newBlock('controls_for');
      block.initSvg();
      block.render();

      // Fire all events
      this.clock.runAll();

      chai.assert.isFalse(block.isEnabled(),
          'Expected orphan block to be disabled after creation');
    });
    test('Created procedure block is enabled', function() {
      this.workspace.addChangeListener(eventUtils.disableOrphans);

      // Procedure block is never an orphan
      let functionBlock = this.workspace.newBlock('procedures_defnoreturn');
      functionBlock.initSvg();
      functionBlock.render();

      // Fire all events
      this.clock.runAll();

      chai.assert.isTrue(functionBlock.isEnabled(),
          'Expected top-level procedure block to be enabled');
    });
    test('Moving a block to top-level disables it', function() {
      this.workspace.addChangeListener(eventUtils.disableOrphans);
      let functionBlock = this.workspace.newBlock('procedures_defnoreturn');
      functionBlock.initSvg();
      functionBlock.render();

      let block = this.workspace.newBlock('controls_for');
      block.initSvg();
      block.render();

      // Connect the block to the function block input stack
      functionBlock.inputList[1].connection.connect(block.previousConnection);

      // Disconnect it again
      block.unplug(false);

      // Fire all events
      this.clock.runAll();

      chai.assert.isFalse(block.isEnabled(),
          'Expected disconnected block to be disabled');
    });
    test('Giving block a parent enables it', function() {
      this.workspace.addChangeListener(eventUtils.disableOrphans);
      let functionBlock = this.workspace.newBlock('procedures_defnoreturn');
      functionBlock.initSvg();
      functionBlock.render();

      let block = this.workspace.newBlock('controls_for');
      block.initSvg();
      block.render();

      // Connect the block to the function block input stack
      functionBlock.inputList[1].connection.connect(block.previousConnection);

      // Fire all events
      this.clock.runAll();

      chai.assert.isTrue(block.isEnabled(),
          'Expected block to be enabled after connecting to parent');
    });
    test('disableOrphans events are not undoable', function() {
      this.workspace.addChangeListener(eventUtils.disableOrphans);
      let functionBlock = this.workspace.newBlock('procedures_defnoreturn');
      functionBlock.initSvg();
      functionBlock.render();

      let block = this.workspace.newBlock('controls_for');
      block.initSvg();
      block.render();

      // Connect the block to the function block input stack
      functionBlock.inputList[1].connection.connect(block.previousConnection);

      // Disconnect it again
      block.unplug(false);

      // Fire all events
      this.clock.runAll();

      let disabledEvents = this.workspace.getUndoStack().filter(function(e) {
        return e.element === 'disabled';
      });
      chai.assert.isEmpty(disabledEvents,
          'Undo stack should not contain any disabled events');
    });
  });
});