I am use jasmine to do a unit test when write a javascript lib, I follow the official doc https://jasmine.github.io/tutorials/your_first_suite, the code demo.js look like this:

'use strict';
    
describe("A suite", function() {
    it("contains spec with an expectation", function() {
      expect(true).toBe(true);
    });
});

when I am using this command to run the unit test:

istanbul cover _mocha ./test/demo.js

show the log output like this:

  A suite
    1) contains spec with an expectation


  0 passing (6ms)
  1 failing

  1) A suite
       contains spec with an expectation:
     ReferenceError: expect is not defined
      at Context.<anonymous> (test/demo.js:7:7)

what should I do avoid this problem? the node version is v10.24.1.The jasmine info:

• jasmine v3.10.0
• jasmine-core v3.10.1

I have tried to install jasmine-expect using this command:

npm install jasmine-expect --save-dev

still not fix it. Tried jasmine like this:

global.expect = require('jasmine-expect').expect;