yoga/src/__tests__/Layout-test.js

var testLayout = layoutTestUtils.testLayout;
var testRandomLayout = layoutTestUtils.testRandomLayout;
var computeLayout = layoutTestUtils.computeLayout;
var computeDOMLayout = layoutTestUtils.computeDOMLayout;
var reduceTest = layoutTestUtils.reduceTest;

describe('Layout', function() {
  it('should layout a single node with width and height', function() {
    testLayout({
      style: {width: 100, height: 200}
    }, {
      width: 100, height: 200, top: 0, left: 0
    });
  });

  it('should layout node with children', function() {
    testLayout(
      {style: {width: 1000, height: 1000}, children: [
        {style: {width: 500, height: 500}},
        {style: {width: 250, height: 250}},
        {style: {width: 125, height: 125}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 500, height: 500, top: 0, left: 0},
        {width: 250, height: 250, top: 500, left: 0},
        {width: 125, height: 125, top: 750, left: 0}
      ]}
    );
  });

  it('should layout node with nested children', function() {
    testLayout(
      {style: {width: 1000, height: 1000}, children: [
        {style: {width: 500, height: 500}},
        {style: {width: 500, height: 500}, children: [
          {style: {width: 250, height: 250}},
          {style: {width: 250, height: 250}}
        ]}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 500, height: 500, top: 0, left: 0},
        {width: 500, height: 500, top: 500, left: 0, children: [
          {width: 250, height: 250, top: 0, left: 0},
          {width: 250, height: 250, top: 250, left: 0},
        ]}
      ]}
    );
  });

  it('should layout node with margin', function() {
    testLayout(
      {style: {width: 100, height: 200, margin: 10}},
      {width: 100, height: 200, top: 10, left: 10}
    );
  });

  it('should layout node with several children', function() {
    testLayout(
      {style: {width: 1000, height: 1000, margin: 10}, children: [
        {style: {width: 100, height: 100, margin: 50}},
        {style: {width: 100, height: 100, margin: 25}},
        {style: {width: 100, height: 100, margin: 10}}
      ]},
      {width: 1000, height: 1000, top: 10, left: 10, children: [
        {width: 100, height: 100, top: 50, left: 50},
        {width: 100, height: 100, top: 225, left: 25},
        {width: 100, height: 100, top: 360, left: 10}
      ]}
    );
  });

  it('should layout node with row flex direction', function() {
    testLayout(
      {style: {width: 1000, height: 1000, flexDirection: 'row'}, children: [
        {style: {width: 100, height: 200}},
        {style: {width: 300, height: 150}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 200, top: 0, left: 0},
        {width: 300, height: 150, top: 0, left: 100}
      ]}
    );
  });

  it('should layout node based on children main dimensions', function() {
    testLayout(
      {style: {width: 300}, children: [
        {style: {width: 100, height: 200}},
        {style: {width: 300, height: 150}}
      ]},
      {width: 300, height: 350, top: 0, left: 0, children: [
        {width: 100, height: 200, top: 0, left: 0},
        {width: 300, height: 150, top: 200, left: 0}
      ]}
    );
  });

  it('should layout node with flex', function() {
    testLayout(
      {style: {width: 1000, height: 1000}, children: [
        {style: {width: 100, height: 200}},
        {style: {width: 100, flex: 1}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 200, top: 0, left: 0},
        {width: 100, height: 800, top: 200, left: 0}
      ]}
    );
  });

  it('should layout node with flex recursively', function() {
    testLayout(
      {style: {width: 1000, height: 1000}, children: [
        {style: {width: 1000, flex: 1}, children: [
          {style: {width: 1000, flex: 1}, children: [
            {style: {width: 1000, flex: 1}}
          ]}
        ]}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 1000, height: 1000, top: 0, left: 0, children: [
          {width: 1000, height: 1000, top: 0, left: 0, children: [
            {width: 1000, height: 1000, top: 0, left: 0}
          ]}
        ]}
      ]}
    );
  });

  it('should layout node with targeted margin', function() {
    testLayout(
      {style: {width: 1000, height: 1000, marginTop: 10, marginLeft: 5}, children: [
        {style: {width: 100, height: 100, marginTop: 50, marginLeft: 15, marginBottom: 20}},
        {style: {width: 100, height: 100, marginLeft: 30}}
      ]},
      {width: 1000, height: 1000, top: 10, left: 5, children: [
        {width: 100, height: 100, top: 50, left: 15},
        {width: 100, height: 100, top: 170, left: 30}
      ]}
    );
  });

  it('should layout node with justifyContent: flex-start', function() {
    testLayout(
      {style: {width: 1000, height: 1000, justifyContent: 'flex-start'}, children: [
        {style: {width: 100, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 100, top: 0, left: 0},
        {width: 100, height: 100, top: 100, left: 0}
      ]}
    );
  });

  it('should layout node with justifyContent: flex-end', function() {
    testLayout(
      {style: {width: 1000, height: 1000, justifyContent: 'flex-end'}, children: [
        {style: {width: 100, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 100, top: 800, left: 0},
        {width: 100, height: 100, top: 900, left: 0}
      ]}
    );
  });

  it('should layout node with justifyContent: space-between', function() {
    testLayout(
      {style: {width: 1000, height: 1000, justifyContent: 'space-between'}, children: [
        {style: {width: 100, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 100, top: 0, left: 0},
        {width: 100, height: 100, top: 900, left: 0}
      ]}
    );
  });

  it('should layout node with justifyContent: space-around', function() {
    testLayout(
      {style: {width: 1000, height: 1000, justifyContent: 'space-around'}, children: [
        {style: {width: 100, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 100, top: 200, left: 0},
        {width: 100, height: 100, top: 700, left: 0}
      ]}
    );
  });

  it('should layout node with justifyContent: center', function() {
    testLayout(
      {style: {width: 1000, height: 1000, justifyContent: 'center'}, children: [
        {style: {width: 100, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 100, top: 400, left: 0},
        {width: 100, height: 100, top: 500, left: 0}
      ]}
    );
  });

  it('should layout node with flex override height', function() {
    testLayout(
      {style: {width: 1000, height: 1000}, children: [
        {style: {width: 100, height: 100, flex: 1}},
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 100, height: 1000, top: 0, left: 0}
      ]}
    );
  });

  it('should layout node with alignItems: flex-start', function() {
    testLayout(
      {style: {width: 1000, height: 1000, alignItems: 'flex-start'}, children: [
        {style: {width: 200, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 200, height: 100, top: 0, left: 0},
        {width: 100, height: 100, top: 100, left: 0},
      ]}
    );
  });

  it('should layout node with alignItems: center', function() {
    testLayout(
      {style: {width: 1000, height: 1000, alignItems: 'center'}, children: [
        {style: {width: 200, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 200, height: 100, top: 0, left: 400},
        {width: 100, height: 100, top: 100, left: 450},
      ]}
    );
  });

  it('should layout node with alignItems: flex-end', function() {
    testLayout(
      {style: {width: 1000, height: 1000, alignItems: 'flex-end'}, children: [
        {style: {width: 200, height: 100}},
        {style: {width: 100, height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 200, height: 100, top: 0, left: 800},
        {width: 100, height: 100, top: 100, left: 900},
      ]}
    );
  });

  it('should layout node with alignSelf overrides alignItems', function() {
    testLayout(
      {style: {width: 1000, height: 1000, alignItems: 'flex-end'}, children: [
        {style: {width: 200, height: 100}},
        {style: {width: 100, height: 100, alignSelf: 'center'}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 200, height: 100, top: 0, left: 800},
        {width: 100, height: 100, top: 100, left: 450},
      ]}
    );
  });

  it('should layout node with alignItem: stretch', function() {
    testLayout(
      {style: {width: 1000, height: 1000, alignItems: 'stretch'}, children: [
        {style: {height: 100}}
      ]},
      {width: 1000, height: 1000, top: 0, left: 0, children: [
        {width: 1000, height: 100, top: 0, left: 0}
      ]}
    );
  });

  it('should layout empty node', function() {
    testLayout(
      {style: {}, children: [
        {style: {}}
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should layout child with margin', function() {
    testLayout(
      {style: {}, children: [
        {style: {margin: 5}}
      ]},
      {width: 10, height: 10, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 5, left: 5}
      ]}
    );
  });

  it('should not shrink children if not enough space', function() {
    testLayout(
      {style: {height: 100}, children: [
        {style: {height: 100}},
        {style: {height: 200}},
      ]},
      {width: 0, height: 100, top: 0, left: 0, children: [
        {width: 0, height: 100, top: 0, left: 0},
        {width: 0, height: 200, top: 100, left: 0}
      ]}
    );
  });

  it('should layout for center', function() {
    testLayout(
      {style: {justifyContent: 'center'}},
      {width: 0, height: 0, top: 0, left: 0}
    );
  });

  it('should layout flex-end taking into account margin', function() {
    testLayout(
      {style: {height: 100, justifyContent: 'flex-end'}, children: [
        {style: {marginTop: 10}}
      ]},
      {width: 0, height: 100, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 100, left: 0}
      ]}
    );
  });

  it('should layout alignItems with margin', function() {
    testLayout(
      {style: {}, children: [
        {style: {alignItems: 'flex-end'}, children: [
          {style: {margin: 10}},
          {style: {height: 100}}
        ]}
      ]},
      {width: 20, height: 120, top: 0, left: 0, children: [
        {width: 20, height: 120, top: 0, left: 0, children: [
          {width: 0, height: 0, top: 10, left: 10},
          {width: 0, height: 100, top: 20, left: 20}
        ]}
      ]}
    );
  });

  it('should layout flex inside of an empty element', function() {
    testLayout(
      {style: {}, children: [
        {style: {flex: 1}},
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should layout alignItems stretch and margin', function() {
    testLayout(
      {style: {alignItems: 'stretch'}, children: [
        {style: {marginLeft: 10}}
      ]},
      {width: 10, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 10}
      ]}
    );
  });

  it('should layout node with padding', function() {
    testLayout(
      {style: {padding: 5}},
      {width: 10, height: 10, top: 0, left: 0}
    );
  });

  it('should layout node with padding and a child', function() {
    testLayout(
      {style: {padding: 5}, children: [
        {style: {}}
      ]},
      {width: 10, height: 10, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 5, left: 5}
      ]}
    );
  });

  it('should layout node with padding and a child with margin', function() {
    testLayout(
      {style: {padding: 5}, children: [
        {style: {margin: 5}}
      ]},
      {width: 20, height: 20, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 10, left: 10}
      ]}
    );
  });

  it('should layout node with padding and stretch', function() {
    testLayout(
      {style: {}, children: [
        {style: {padding: 10, alignSelf: 'stretch'}}
      ]},
      {width: 20, height: 20, top: 0, left: 0, children: [
        {width: 20, height: 20, top: 0, left: 0}
      ]}
    );
  });

  it('should layout node with inner & outer padding and stretch', function() {
    testLayout(
      {style: {padding: 50}, children: [
        {style: {padding: 10, alignSelf: 'stretch'}}
      ]},
      {width: 120, height: 120, top: 0, left: 0, children: [
        {width: 20, height: 20, top: 50, left: 50}
      ]}
    );
  });

  it('should layout node with stretch and child with margin', function() {
    testLayout(
      {style: {}, children: [
        {style: {alignSelf: 'stretch'}, children: [
          {style: {margin: 16}}
        ]}
      ]},
      {width: 32, height: 32, top: 0, left: 0, children: [
        {width: 32, height: 32, top: 0, left: 0, children: [
          {width: 0, height: 0, top: 16, left: 16}
        ]}
      ]}
    );
  });

  it('should layout node with top and left', function() {
    testLayout(
      {style: {top: 5, left: 5}},
      {width: 0, height: 0, top: 5, left: 5}
    );
  });

  it('should layout node with height, padding and space-around', function() {
    testLayout(
      {style: {height: 10, paddingTop: 5, justifyContent: 'space-around'}, children: [
        {style: {}}
      ]},
      {width: 0, height: 10, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 7.5, left: 0}
      ]}
    );
  });

  it('should layout node with bottom', function() {
    testLayout(
      {style: {bottom: 5}},
      {width: 0, height: 0, top: -5, left: 0}
    );
  });

  it('should layout node with both top and bottom', function() {
    testLayout(
      {style: {top: 10, bottom: 5}},
      {width: 0, height: 0, top: 10, left: 0}
    );
  });

  it('should layout node with position: absolute', function() {
    testLayout(
      {style: {width: 500, flexDirection: 'row'}, children: [
        {style: {flex: 1}},
        {style: {position: 'absolute', width: 50}},
        {style: {flex: 1}},
      ]},
      {width: 500, height: 0, top: 0, left: 0, children: [
        {width: 250, height: 0, top: 0, left: 0},
        {width: 50, height: 0, top: 0, left: 250},
        {width: 250, height: 0, top: 0, left: 250}
      ]}
    );
  });

  it('should layout node with child with position: absolute and margin', function() {
    testLayout(
      {style: {}, children: [
        {style: {marginRight: 15, position: 'absolute'}}
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should layout node with position: absolute, padding and alignSelf: center', function() {
    testLayout(
      {style: {}, children: [
        {style: {paddingRight: 12, alignSelf: 'center', position: 'absolute'}}
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 12, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should work with height smaller than paddingBottom', function() {
    testLayout(
      {style: {height: 5, paddingBottom: 20}},
      {width: 0, height: 20, top: 0, left: 0}
    );
  });

  it('should work with width smaller than paddingLeft', function() {
    testLayout(
      {style: {width: 5, paddingLeft: 20}},
      {width: 20, height: 0, top: 0, left: 0}
    );
  });

  it('should layout node with specified width and stretch', function() {
    testLayout(
      {style: {}, children: [{
        style: {}, children: [
          {style: {width: 400}}
        ]},
        {style: {width: 200, alignSelf: 'stretch'}}
      ]},
      {width: 400, height: 0, top: 0, left: 0, children: [
        {width: 400, height: 0, top: 0, left: 0, children: [
          {width: 400, height: 0, top: 0, left: 0}
        ]},
        {width: 200, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should layout node with padding and child with position absolute', function() {
    testLayout(
      {style: {padding: 5}, children: [
        {style: {position: 'absolute'}}
      ]},
      {width: 10, height: 10, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 5, left: 5}
      ]}
    );
  });

  it('should layout node with position absolute, top and left', function() {
    testLayout(
      {style: {}, children: [
        {style: {height: 100}},
        {style: {position: 'absolute', top: 10, left: 10}}
      ]},
      {width: 0, height: 100, top: 0, left: 0, children: [
        {width: 0, height: 100, top: 0, left: 0},
        {width: 0, height: 0, top: 10, left: 10}
      ]}
    );
  });

  it('should layout node with padding and child position absolute, left', function() {
    testLayout(
      {style: {padding: 20}, children: [
        {style: {left: 5, position: 'absolute'}}
      ]},
      {width: 40, height: 40, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 20, left: 5}
      ]}
    );
  });

  it('should layout node with position: absolute, top and marginTop', function() {
    testLayout(
      {style: {}, children: [
        {style: {top: 5, marginTop: 5, position: 'absolute'}}
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 10, left: 0}
      ]}
    );
  });

  it('should layout node with position: absolute, left and marginLeft', function() {
    testLayout(
      {style: {}, children: [
        {style: {left: 5, marginLeft: 5, position: 'absolute'}}
      ]},
      {width: 0, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 10}
      ]}
    );
  });

  it('should layout node with space-around and child position absolute', function() {
    testLayout(
      {style: {height: 200, justifyContent: 'space-around'}, children: [
        {style: {position: 'absolute'}},
        {style: {}}
      ]},
      {width: 0, height: 200, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 100, left: 0},
        {width: 0, height: 0, top: 100, left: 0}
      ]}
    );
  });

  it('should layout node with flex and main margin', function() {
    testLayout(
      {style: {width: 700, flexDirection: 'row'}, children: [
        {style: {marginLeft: 5, flex: 1}}
      ]},
      {width: 700, height: 0, top: 0, left: 0, children: [
        {width: 695, height: 0, top: 0, left: 5}
      ]}
    );
  });

  it('should layout node with multiple flex and padding', function() {
    testLayout(
      {style: {width: 700, flexDirection: 'row'}, children: [
        {style: {flex: 1}},
        {style: {paddingRight: 5, flex: 1}}
      ]},
      {width: 700, height: 0, top: 0, left: 0, children: [
        {width: 347.5, height: 0, top: 0, left: 0},
        {width: 352.5, height: 0, top: 0, left: 347.5}
      ]}
    );
  });

  it('should layout node with multiple flex and margin', function() {
    testLayout(
      {style: {width: 700, flexDirection: 'row'}, children: [
        {style: {flex: 1}},
        {style: {marginLeft: 5, flex: 1}}
      ]},
      {width: 700, height: 0, top: 0, left: 0, children: [
        {width: 347.5, height: 0, top: 0, left: 0},
        {width: 347.5, height: 0, top: 0, left: 352.5}
      ]}
    )
  });

  it('should layout node with flex and overflow', function() {
    testLayout(
      {style: {height: 300}, children: [
        {style: {height: 600}},
        {style: {flex: 1}}
      ]},
      {width: 0, height: 300, top: 0, left: 0, children: [
        {width: 0, height: 600, top: 0, left: 0},
        {width: 0, height: 0, top: 600, left: 0}
      ]}
    );
  });

  it('should layout node with flex and position absolute', function() {
    testLayout(
      {style: {width: 600, flexDirection: 'row'}, children: [
        {style: {flex: 1, position: 'absolute'}}
      ]},
      {width: 600, height: 0, top: 0, left: 0, children: [
        {width: 0, height: 0, top: 0, left: 0}
      ]}
    );
  });

  it('should layout node with double flex and position absolute', function() {
    testLayout(
      {style: {height: 500}, children: [
        {style: {flex: 1}},
        {style: {flex: 1, position: 'absolute'}}
      ]},
      {width: 0, height: 500, top: 0, left: 0, children: [
        {width: 0, height: 500, top: 0, left: 0},
        {width: 0, height: 0, top: 500, left: 0},
      ]}
    )
  });

  it('should layout node with borderWidth', function() {
    testLayout(
      {style: {borderWidth: 5}},
      {width: 10, height: 10, top: 0, left: 0}
    )
  });



  it('should layout randomly', function() {
    function RNG(seed) {
      this.state = seed;
    }
    RNG.prototype.nextFloat = function() {
      // LCG using GCC's constants
      this.state = (1103515245 * this.state + 12345) % 0x80000000;
      return this.state / (0x80000000 - 1);
    }

    var rng = new RNG(0);
    function randMinMax(node, chance, attribute, min, max) {
      if (rng.nextFloat() < chance) {
        if (attribute === 'right' || attribute === 'bottom') {
          return;
        }
        node.style[attribute] = Math.floor(rng.nextFloat() * (max - min)) + min;
      }
    }
    function randEnum(node, chance, attribute, enumValues) {
      if (rng.nextFloat() < chance) {
        node.style[attribute] = enumValues[Math.floor(rng.nextFloat() * enumValues.length)];
      }
    }
    function randChildren(node, chance) {
      while (rng.nextFloat() < chance) {
        if (!node.children) {
          node.children = [];
        }
        node.children.push(generateRandomNode());
      }
    }
    function randSpacing(node, chance, type, suffix, min, max) {
      randMinMax(node, chance, type + suffix, min, max);
      randMinMax(node, chance, type + 'Left' + suffix, min, max);
      randMinMax(node, chance, type + 'Top' + suffix, min, max);
      randMinMax(node, chance, type + 'Right' + suffix, min, max);
      randMinMax(node, chance, type + 'Bottom' + suffix, min, max);
    }
    function generateRandomNode() {
      var node = {style: {}};
      randMinMax(node, 0.5, 'width', 0, 1000);
      randMinMax(node, 0.5, 'height', 0, 1000);
      randMinMax(node, 0.5, 'top', -10, 10);
      randMinMax(node, 0.5, 'left', -10, 10);
      randMinMax(node, 0.5, 'right', -10, 10);
      randMinMax(node, 0.5, 'bottom', -10, 10);
      randSpacing(node, 0.5, 'margin', '', 0, 20);
      randSpacing(node, 0.5, 'padding', '', 0, 20);
      randSpacing(node, 0.5, 'border', 'Width', 0, 4);
      randEnum(node, 0.5, 'flexDirection', ['column', 'row']);
      randEnum(node, 0.5, 'justifyContent', ['flex-start', 'center', 'flex-end', 'space-between', 'space-around']);
      randEnum(node, 0.5, 'alignItems', ['flex-start', 'center', 'flex-end', 'stretch']);
      randEnum(node, 0.5, 'alignSelf', ['flex-start', 'center', 'flex-end', 'stretch']);
      randEnum(node, 0.5, 'flex', ['none', 1]);
      randEnum(node, 0.5, 'position', ['relative', 'absolute']);
      randChildren(node, 0.2);
      return node;
    }

    for (var i = 0; i < 100; ++i) {
      var node = generateRandomNode();

      if (JSON.stringify(computeLayout(node)) !== JSON.stringify(computeDOMLayout)) {
        node = reduceTest(node);
      }

      // The iframe's body has a natural width of 300 that it doesn't really make
      // to replicate in the test suite. The easiest workaround is not to test
      // alignSelf, position and flex properties on the root element.
      delete node.style.alignSelf;
      delete node.style.flex;
      delete node.style.position;

      testRandomLayout(node, i);
    }
  })

});