jasmine - Reset an ES6 module with SystemJS (for unit tests)? -

our workflow includes using es6 modules. includes unit tests. import modules under test. problem original authors decided have every module return objects, , have global singletons (because of how es6 imports work) throughout code base---a classic unit testing problem.

is there way "reset" said modules systemjs after each test?

sample unit test (loaded karma-systemjs):

import mut './mut' // module under test  describe('mut', () => {     it('should stuff', () => {        mut.value = 'foo'    })     it('should more stuff', () => {        // value should not 'foo' here. how reset mut?    }) 

check out this issue on github, , particularly this comment.

try deleting , re-importing module in beforeeach block so:

describe('mut', () => {    let mut;    beforeeach((done) => {     // remove previous version     system.delete(system.normalizesync('./mut'))     // re-import module     system.import('./mut').then((imported) => {       mut = imported     }).then(done, fail)   })    it('should stuff, () => {     mut.value = 'foo'     expect(mut.value).tobe('foo')   })    it('should more stuff', () => {     expect(mut.value).not.tobe('foo')   })  })