vitest-marbles
Version:
Marble testing helpers library for RxJs and Jest
138 lines (120 loc) • 4.69 kB
text/typescript
import { type MatchersObject } from '@vitest/expect';
import {type Assertion, type AsymmetricMatchersContaining } from 'vitest';
import { Marblizer } from '../marblizer';
import { SubscriptionLog, TestMessages } from '../rxjs/types';
function canMarblize(...messages: TestMessages[]) {
return messages.every(message => message.filter(({ notification: { kind } }) => kind === 'N').every(isCharacter));
}
function isCharacter({ notification }: TestMessages[0]): boolean {
const value = (notification as any).value;
return (
(typeof value === 'string' && value.length === 1) || (value !== undefined && JSON.stringify(value).length === 1)
);
}
export const customTestMatchers: MatchersObject = {
toBeNotifications(actual: TestMessages, expected: TestMessages) {
let actualMarble: string | TestMessages = actual;
let expectedMarble: string | TestMessages = expected;
if (canMarblize(actual, expected)) {
actualMarble = Marblizer.marblize(actual);
expectedMarble = Marblizer.marblize(expected);
}
const pass = this.equals(actualMarble, expectedMarble);
const message = pass
? () =>
this.utils.matcherHint('.not.toBeNotifications') +
'\n\n' +
`Expected notifications to not be:\n` +
` ${this.utils.printExpected(expectedMarble)}\n` +
`But got:\n` +
` ${this.utils.printReceived(actualMarble)}`
: () => {
const diffString = this.utils.diff(expectedMarble, actualMarble, {
expand: true,
});
return (
this.utils.matcherHint('.toBeNotifications') +
'\n\n' +
`Expected notifications to be:\n` +
` ${this.utils.printExpected(expectedMarble)}\n` +
`But got:\n` +
` ${this.utils.printReceived(actualMarble)}` +
(diffString ? `\n\nDifference:\n\n${diffString}` : '')
);
};
return { message, pass };
},
toBeSubscriptions(actual: SubscriptionLog[], expected: SubscriptionLog[]) {
const actualMarbleArray = Marblizer.marblizeSubscriptions(actual);
const expectedMarbleArray = Marblizer.marblizeSubscriptions(expected);
const pass = subscriptionsPass(actualMarbleArray, expectedMarbleArray);
const message = pass
? () =>
this.utils.matcherHint('.not.toHaveSubscriptions') +
'\n\n' +
`Expected observable to not have the following subscription points:\n` +
` ${this.utils.printExpected(expectedMarbleArray)}\n` +
`But got:\n` +
` ${this.utils.printReceived(actualMarbleArray)}`
: () => {
const diffString = this.utils.diff(expectedMarbleArray, actualMarbleArray, {
expand: true,
});
return (
this.utils.matcherHint('.toHaveSubscriptions') +
'\n\n' +
`Expected observable to have the following subscription points:\n` +
` ${this.utils.printExpected(expectedMarbleArray)}\n` +
`But got:\n` +
` ${this.utils.printReceived(actualMarbleArray)}` +
(diffString ? `\n\nDifference:\n\n${diffString}` : '')
);
};
return { message, pass };
},
toHaveEmptySubscriptions(actual: SubscriptionLog[] | undefined) {
const pass = !(actual && actual.length > 0);
let marbles: string[];
if (actual && actual.length > 0) {
marbles = Marblizer.marblizeSubscriptions(actual);
}
const message = pass
? () =>
this.utils.matcherHint('.not.toHaveNoSubscriptions') +
'\n\n' +
`Expected observable to have at least one subscription point, but got nothing` +
this.utils.printReceived('')
: () =>
this.utils.matcherHint('.toHaveNoSubscriptions') +
'\n\n' +
`Expected observable to have no subscription points\n` +
`But got:\n` +
` ${this.utils.printReceived(marbles)}\n\n`;
return { message, pass };
},
};
function subscriptionsPass(actualMarbleArray: string[], expectedMarbleArray: string[]): boolean {
if (actualMarbleArray.length !== expectedMarbleArray.length) {
return false;
}
let pass = true;
for (const actualMarble of actualMarbleArray) {
if (!expectedMarbleArray.includes(actualMarble)) {
pass = false;
break;
}
}
return pass;
}
interface VitestMarblesMatchers {
toBeNotifications(notifications: TestMessages): void;
toBeSubscriptions(subscriptions: SubscriptionLog[]): void;
toHaveEmptySubscriptions(): void;
}
declare module 'vitest' {
interface Assertion extends VitestMarblesMatchers {
}
interface AsymmetricMatchersContaining extends VitestMarblesMatchers {
}
}
expect.extend(customTestMatchers);