memfs - Jest manual mocks (for fs) bootstrap
Using memfs for jest manual mock of node's fs module.
API
const fs = require('fs')
const json = {
'./README.md': '1',
'./src/index.js': '2',
'./node_modules/debug/index.js': '3',
};
const folder = '/app'
// initialing folder
fs.__fromJSON(json, folder);
// return internal representation
fs.__asJSON()
Example
jest.mock('fs');
describe('copy test', () => {
const json = {
'./README.md': '1',
'./src/index.js': '2',
'./node_modules/debug/index.js': '3',
};
const fs = require('fs')
fs.__fromJSON(json, '/app');
const val1 = fs.readFileSync('/app/README.md', 'utf8'); // 1
it('read val 1', () => {
expect(val1).toEqual('1')
})
const val2 = fs.readFileSync('/app/src/index.js', 'utf8'); // 2
it('read val 2', () => {
expect(val2).toEqual('2')
})
const val3 = fs.__asJSON(); // 2
it('internal read', () => {
expect(val3['/app/node_modules/debug/index.js']).toEqual('3')
})
})