Syllabus/themes/piratecare/node_modules/dependency-graph/specs/dep_graph_spec.js

var dep_graph = require('../lib/dep_graph');
var DepGraph = dep_graph.DepGraph;

describe('DepGraph', function () {

  it('should be able to add/remove nodes', function () {
    var graph = new DepGraph();

    graph.addNode('Foo');
    graph.addNode('Bar');

    expect(graph.hasNode('Foo')).toBeTrue();
    expect(graph.hasNode('Bar')).toBeTrue();
    expect(graph.hasNode('NotThere')).toBeFalse();

    graph.removeNode('Bar');

    expect(graph.hasNode('Bar')).toBeFalse();
  });

  it('should calculate its size', function () {
    var graph = new DepGraph();

    expect(graph.size()).toBe(0);

    graph.addNode('Foo');
    graph.addNode('Bar');

    expect(graph.size()).toBe(2);

    graph.removeNode('Bar');

    expect(graph.size()).toBe(1);
  });

  it('should treat the node data parameter as optional and use the node name as data if node data was not given', function () {
    var graph = new DepGraph();

    graph.addNode('Foo');

    expect(graph.getNodeData('Foo')).toBe('Foo');
  });

  it('should be able to associate a node name with data on node add', function () {
    var graph = new DepGraph();

    graph.addNode('Foo', 'data');

    expect(graph.getNodeData('Foo')).toBe('data');
  });

  it('should be able to add undefined as node data', function () {
    var graph = new DepGraph();

    graph.addNode('Foo', undefined);

    expect(graph.getNodeData('Foo')).toBeUndefined();
  });

  it('should return true when using hasNode with a node which has falsy data', function () {
    var graph = new DepGraph();

    var falsyData = ['', 0, null, undefined, false];
    graph.addNode('Foo');

    falsyData.forEach(function (data) {
      graph.setNodeData('Foo', data);

      expect(graph.hasNode('Foo')).toBeTrue();

      // Just an extra check to make sure that the saved data is correct
      expect(graph.getNodeData('Foo')).toBe(data);
    });
  });

  it('should be able to set data after a node was added', function () {
    var graph = new DepGraph();

    graph.addNode('Foo', 'data');
    graph.setNodeData('Foo', 'data2');

    expect(graph.getNodeData('Foo')).toBe('data2');
  });

  it('should throw an error if we try to set data for a non-existing node', function () {
    var graph = new DepGraph();

    expect(function () {
      graph.setNodeData('Foo', 'data');
    }).toThrow(new Error('Node does not exist: Foo'));
  });

  it('should throw an error if the node does not exists and we try to get data', function () {
    var graph = new DepGraph();

    expect(function () {
      graph.getNodeData('Foo');
    }).toThrow(new Error('Node does not exist: Foo'));
  });

  it('should do nothing if creating a node that already exists', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');

    graph.addDependency('a', 'b');

    graph.addNode('a');

    expect(graph.dependenciesOf('a')).toEqual(['b']);
  });

  it('should do nothing if removing a node that does not exist', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    expect(graph.hasNode('a')).toBeTrue();

    graph.removeNode('a');
    expect(graph.hasNode('Foo')).toBeFalse();

    graph.removeNode('a');
    expect(graph.hasNode('Foo')).toBeFalse();
  });

  it('should be able to add dependencies between nodes', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');

    graph.addDependency('a', 'b');
    graph.addDependency('a', 'c');

    expect(graph.dependenciesOf('a')).toEqual(['b', 'c']);
  });

  it('should throw an error if a node does not exist and a dependency is added', function () {
    var graph = new DepGraph();

    graph.addNode('a');

    expect(function () {
      graph.addDependency('a', 'b');
    }).toThrow(new Error('Node does not exist: b'));
  });

  it('should detect cycles', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');

    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'a');
    graph.addDependency('d', 'a');

    expect(function () {
      graph.dependenciesOf('b');
    }).toThrow(new dep_graph.DepGraphCycleError(['b', 'c', 'a', 'b']));
  });

  it('should allow cycles when configured', function () {
    var graph = new DepGraph({ circular: true });

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');

    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'a');
    graph.addDependency('d', 'a');

    expect(graph.dependenciesOf('b')).toEqual(['a', 'c']);
    expect(graph.overallOrder()).toEqual(['c', 'b', 'a', 'd']);
  });

  it('should include all nodes in overall order even from ' +
    'cycles in disconnected subgraphs when circular is true', function () {
      var graph = new DepGraph({ circular: true });

      graph.addNode('2a');
      graph.addNode('2b');
      graph.addNode('2c');
      graph.addDependency('2a', '2b');
      graph.addDependency('2b', '2c');
      graph.addDependency('2c', '2a');

      graph.addNode('1a');
      graph.addNode('1b');
      graph.addNode('1c');
      graph.addNode('1d');
      graph.addNode('1e');

      graph.addDependency('1a', '1b');
      graph.addDependency('1a', '1c');
      graph.addDependency('1b', '1c');
      graph.addDependency('1c', '1d');

      expect(graph.overallOrder()).toEqual(['1d', '1c', '1b', '1a', '1e', '2c', '2b', '2a']);
    });

  it('should detect cycles in overall order', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');

    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'a');
    graph.addDependency('d', 'a');

    expect(function () {
      graph.overallOrder();
    }).toThrow(new dep_graph.DepGraphCycleError(['a', 'b', 'c', 'a']));
  });

  it('should detect cycles in overall order when all nodes have dependants (incoming edges)', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');

    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'a');

    expect(function () {
      graph.overallOrder();
    }).toThrow(new dep_graph.DepGraphCycleError(['a', 'b', 'c', 'a']));
  });

  it('should detect cycles in overall order when there are several ' +
    'disconnected subgraphs (with one that does not have a cycle', function () {
      var graph = new DepGraph();

      graph.addNode('a_1');
      graph.addNode('a_2');
      graph.addNode('b_1');
      graph.addNode('b_2');
      graph.addNode('b_3');

      graph.addDependency('a_1', 'a_2');
      graph.addDependency('b_1', 'b_2');
      graph.addDependency('b_2', 'b_3');
      graph.addDependency('b_3', 'b_1');

      expect(function () {
        graph.overallOrder();
      }).toThrow(new dep_graph.DepGraphCycleError(['b_1', 'b_2', 'b_3', 'b_1']));
    });

  it('should retrieve dependencies and dependants in the correct order', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');

    graph.addDependency('a', 'd');
    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');
    graph.addDependency('d', 'b');

    expect(graph.dependenciesOf('a')).toEqual(['c', 'b', 'd']);
    expect(graph.dependenciesOf('b')).toEqual(['c']);
    expect(graph.dependenciesOf('c')).toEqual([]);
    expect(graph.dependenciesOf('d')).toEqual(['c', 'b']);

    expect(graph.dependantsOf('a')).toEqual([]);
    expect(graph.dependantsOf('b')).toEqual(['a', 'd']);
    expect(graph.dependantsOf('c')).toEqual(['a', 'd', 'b']);
    expect(graph.dependantsOf('d')).toEqual(['a']);
  });

  it('should be able to resolve the overall order of things', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');
    graph.addNode('e');

    graph.addDependency('a', 'b');
    graph.addDependency('a', 'c');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'd');

    expect(graph.overallOrder()).toEqual(['d', 'c', 'b', 'a', 'e']);
  });

  it('should be able to only retrieve the "leaves" in the overall order', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addNode('d');
    graph.addNode('e');

    graph.addDependency('a', 'b');
    graph.addDependency('a', 'c');
    graph.addDependency('b', 'c');
    graph.addDependency('c', 'd');

    expect(graph.overallOrder(true)).toEqual(['d', 'e']);
  });

  it('should be able to give the overall order for a graph with several disconnected subgraphs', function () {
    var graph = new DepGraph();

    graph.addNode('a_1');
    graph.addNode('a_2');
    graph.addNode('b_1');
    graph.addNode('b_2');
    graph.addNode('b_3');

    graph.addDependency('a_1', 'a_2');
    graph.addDependency('b_1', 'b_2');
    graph.addDependency('b_2', 'b_3');

    expect(graph.overallOrder()).toEqual(['a_2', 'a_1', 'b_3', 'b_2', 'b_1']);
  });

  it('should give an empty overall order for an empty graph', function () {
    var graph = new DepGraph();

    expect(graph.overallOrder()).toEqual([]);
  });

  it('should still work after nodes are removed', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');

    expect(graph.dependenciesOf('a')).toEqual(['c', 'b']);

    graph.removeNode('c');

    expect(graph.dependenciesOf('a')).toEqual(['b']);
  });

  it('should clone an empty graph', function () {
    var graph = new DepGraph();
    expect(graph.size()).toEqual(0);
    var cloned = graph.clone();
    expect(cloned.size()).toEqual(0);

    expect(graph === cloned).toBeFalse();
  });

  it('should clone a non-empty graph', function () {
    var graph = new DepGraph();

    graph.addNode('a');
    graph.addNode('b');
    graph.addNode('c');
    graph.addDependency('a', 'b');
    graph.addDependency('b', 'c');

    var cloned = graph.clone();

    expect(graph === cloned).toBeFalse();
    expect(cloned.hasNode('a')).toBeTrue();
    expect(cloned.hasNode('b')).toBeTrue();
    expect(cloned.hasNode('c')).toBeTrue();
    expect(cloned.dependenciesOf('a')).toEqual(['c', 'b']);
    expect(cloned.dependantsOf('c')).toEqual(['a', 'b']);

    // Changes to the original graph shouldn't affect the clone
    graph.removeNode('c');
    expect(graph.dependenciesOf('a')).toEqual(['b']);
    expect(cloned.dependenciesOf('a')).toEqual(['c', 'b']);

    graph.addNode('d');
    graph.addDependency('b', 'd');
    expect(graph.dependenciesOf('a')).toEqual(['d', 'b']);
    expect(cloned.dependenciesOf('a')).toEqual(['c', 'b']);
  });

  it('should only be a shallow clone', function () {
    var graph = new DepGraph();

    var data = { a: 42 };
    graph.addNode('a', data);

    var cloned = graph.clone();
    expect(graph === cloned).toBeFalse();
    expect(graph.getNodeData('a') === cloned.getNodeData('a')).toBeTrue();

    graph.getNodeData('a').a = 43;
    expect(cloned.getNodeData('a').a).toBe(43);

    cloned.setNodeData('a', { a: 42 });
    expect(cloned.getNodeData('a').a).toBe(42);
    expect(graph.getNodeData('a') === cloned.getNodeData('a')).toBeFalse();
  });
});

describe('DepGraphCycleError', function () {
  var DepGraphCycleError = dep_graph.DepGraphCycleError;

  it('should have a message', function () {
    var err = new DepGraphCycleError(['a', 'b', 'c', 'a']);
    expect(err.message).toEqual('Dependency Cycle Found: a -> b -> c -> a');
  });

  it('should be an instanceof DepGraphCycleError', function () {
    var err = new DepGraphCycleError(['a', 'b', 'c', 'a']);
    expect(err instanceof DepGraphCycleError).toBeTrue();
    expect(err instanceof Error).toBeTrue();
  });

  it('should have a cyclePath', function () {
    var cyclePath = ['a', 'b', 'c', 'a'];
    var err = new DepGraphCycleError(cyclePath);
    expect(err.cyclePath).toEqual(cyclePath);
  });
});