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;
      }
  });
});

How do you import this in you test file?

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);
   });
});