I have written two yasnippets for Jasmine that are really useful for me. One creates a describe and one create an it.

My snippets create this:

describe("", () => {

});

it("", () => {

});

The code for the snippets:

# -*- mode: snippet -*-
# name: jasmine.desc
# key: desc
# --
describe("$1", () => {
$2
});
# -*- mode: snippet -*-
# name: jasmine.it
# key: it
# --
it("$1", () => {
$2
});

If you want to use them, install yasnippet, create two files yasmin.it.yasnippet and yasmin.describe.yasnippet and put them in .emacs.d/snippets/js-mode. This is how it looks for me.