jasmine matcher in typescript - example. This one does the same as toEqual does on arrays.

jasmine.matcher.ts

module jasmine {
  interface Matchers {
    toHaveSameSequence(expected: any[]): boolean;
  }
}

beforeEach(function () {
  this.addMatchers(
    {
      toHaveSameSequence: function(expected: any[]) {
        var a = this.actual;
        for (var i = 0; i < a.length; i++) {
          if (a[i] != expected[i]) return false;
        }
        return true;
      }
  });
});

Load the file containing the custom matcher as spec file and the beforeEach() gets invoked automatically in the context of the test environment. Then you should have your custom-matcher available:

describe ("MyTest", () => {
   const expected = [1,2,3];

   it("should have thee same sequence", () => {
      const actual = [1,2,3];
      expect(actual).toHaveSameSequence(expected);
   });
});