micro stubbing library for javascript environments
I like big sbuts and I cannot lie. Mc Hammer
A method stub or simply stub in software development is a piece of code used to stand in for some other programming functionality. Wikipedia
npm install --save-dev sbuts (or from CDN etc)
The module has a single export
import stub from 'sbuts';
// etcThe low level API always come back to a generator to get the best flexibility, but higher level syntax sugar is also available
- Stub produces a value
let fn = stub(function *(){
yield 42;
});
// or
fn = stub(42);
// or
fn = stub().return(42);
fn('whatever') === 42; // > true- Stub produces a list of values when called multiple times
fn = stub(function *(){
yield 42;
yield 'woot';
});
// or
fn = stub(42,'woot');
// or
fn = stub()
.return(42)
.return('woot'); // can be called later
fn('foo') === 42; // > true
fn(66) === 'woot'; // > true- Stub throws an error
fn = stub(function *(){
throw new Error('some error');
});
or
fn = stub().throw(new Error('some error'));
try{
fn();
} catch(e){
e.message === 'some error'; // > true
}- stub async function
fn = stub(async function *(){
yield 42;
});
// or
fn = stub(function * (){
yield Promise.resolve(42);
});
// or
fn = stub(Promise.resolve(42));
// or
fn = stub().resolve(42);
// or ... probably other ways but you get the idea
val === await fn() // > true- stub async error
fn = stub(async function *(){
throw new Error('some error');
});
// or
fn = stub(function * (){
yield Promise.reject(new Error('some error'));
});
// or
fn = stub(Promise.reject(new Error('some message')));
// or
fn = stub().reject(new Error('some message'));
// or ... probably other ways but you get the idea
try {
await fn(`woot bim`)
} catch (e) {
e.message === `some message` // > true
}Every call captures the arguments, so you can make some assertions on how the stub was called:
const fn = stub(function *(){
let i = 0;
while(true){
yield ++i;
}
});
fn(null, 42);
fn({foo:'bar'});
fn.calls; // > [ [null, 42], [ {foo:'bar'} ] ]