gecko/toolkit/content/tests/browser/browser_Geometry.js

function test() {
  ok(Rect, "Rect class exists");
  for (var fname in tests) {
    tests[fname]();
  }
}

let tests = {
  testGetDimensions: function() {
    let r = new Rect(5, 10, 100, 50);
    ok(r.left == 5, "rect has correct left value");
    ok(r.top == 10, "rect has correct top value");
    ok(r.right == 105, "rect has correct right value");
    ok(r.bottom == 60, "rect has correct bottom value");
    ok(r.width == 100, "rect has correct width value");
    ok(r.height == 50, "rect has correct height value");
    ok(r.x == 5, "rect has correct x value");
    ok(r.y == 10, "rect has correct y value");
  },

  testIsEmpty: function() {
    let r = new Rect(0, 0, 0, 10);
    ok(r.isEmpty(), "rect with nonpositive width is empty");
    let r = new Rect(0, 0, 10, 0);
    ok(r.isEmpty(), "rect with nonpositive height is empty");
    let r = new Rect(0, 0, 10, 10);
    ok(!r.isEmpty(), "rect with positive dimensions is not empty");
  },

  testRestrictTo: function() {
    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(50, 50, 100, 100);
    r1.restrictTo(r2);
    ok(r1.equals(new Rect(50, 50, 60, 60)), "intersection is non-empty");

    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(120, 120, 100, 100);
    r1.restrictTo(r2);
    ok(r1.isEmpty(), "intersection is empty");

    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(0, 0, 0, 0);
    r1.restrictTo(r2);
    ok(r1.isEmpty(), "intersection of rect and empty is empty");

    let r1 = new Rect(0, 0, 0, 0);
    let r2 = new Rect(0, 0, 0, 0);
    r1.restrictTo(r2);
    ok(r1.isEmpty(), "intersection of empty and empty is empty");
  },

  testExpandToContain: function() {
    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(50, 50, 100, 100);
    r1.expandToContain(r2);
    ok(r1.equals(new Rect(10, 10, 140, 140)), "correct expandToContain on intersecting rectangles");

    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(120, 120, 100, 100);
    r1.expandToContain(r2);
    ok(r1.equals(new Rect(10, 10, 210, 210)), "correct expandToContain on non-intersecting rectangles");

    let r1 = new Rect(10, 10, 100, 100);
    let r2 = new Rect(0, 0, 0, 0);
    r1.expandToContain(r2);
    ok(r1.equals(new Rect(10, 10, 100, 100)), "expandToContain of rect and empty is rect");

    let r1 = new Rect(10, 10, 0, 0);
    let r2 = new Rect(0, 0, 0, 0);
    r1.expandToContain(r2);
    ok(r1.isEmpty(), "expandToContain of empty and empty is empty");
  }
};