Run Jasmine Tests Sequentially

set "random" to false in jasmine.json

The file should be added in spec/support/jasmine.json

I don't think that async tests will run two tests at the exact same time. This side effect is most likely happening because you are not reseting your global functions after the individual test ends. If you don't restore the global function after each test and the next test that runs (which could be any individual test in your suite) could fail if it relies on the same function.

For example (using sinon)

describe("A suite", function() {
    beforeEach(function() {
      sinon.stub(someGlobal, 'someFunc')
    });

    afterEach(function() {
      someGlobal.sumFunc.restore()
    })

    it("uses global function", function() {
      ...
    });
});

*You can, however, set random to false in your jasmine config to run your specs in order - https://jasmine.github.io/setup/nodejs.html.