Assertions

Assertions

HTTP checks

Queue them on the builder (they replay in order when awaited) or call them on a resolved response. Each returns the response and throws AssertionError on failure, with messages like <METHOD> <URL> -> <what went wrong>.

Status: expectStatus(code), expectStatusIn(...codes), expectOk(), expectClientError(), expectServerError(), expectRedirect(), expectCreated(), expectAccepted(), expectNoContent(), expectBadRequest(), expectUnauthorized(), expectForbidden(), expectNotFound().

Headers and cookies: expectHeader(name, matcher?), expectHeaderContains(name, substr), expectHeaderAbsent(name), expectContentType(type), expectCookie(name, matcher?).

Body and JSON: expectJson(path, expected?), expectJsonLength(path, n), expectArrayLength(path, n), expectJsonContains(path, value), expectJsonSchema(schema), expectSorted(path, options?), expectBody(matcher), expectBodyContains(substr), expectEmpty(), expectNotEmpty(), expectTimeBelow(ms), check(label, fn), expectValue(path).

const res = await api.get("/users").expectOk();
res.expectValue("data[0].id").toBeGreaterThan(0);
res.expectJsonContains("users", { id: 2 });
res.expectSorted("data", { key: "id", order: "asc" });

Matchers

expectHeader, expectJson, and expectBody accept a flexible matcher: a RegExp (tested against the string), a function (predicate), an object or array (deep equality), or a primitive (strict ===).

expect() for any value

expect(value) works on anything, with .not and .resolves / .rejects.

import { expect } from "two-go";

expect(2 + 2).toBe(4);
expect({ a: 1, b: 2 }).toMatchObject({ a: 1 });
expect([1, 2, 3]).toContain(2);
expect("hello").toMatch(/ell/);
expect(value).not.toBeNull();
await expect(Promise.resolve(5)).resolves.toBe(5);

Matchers: toBe, toEqual, toStrictEqual, toBeTruthy/Falsy, toBeNull/Undefined/Defined/NaN, toBeGreaterThan(OrEqual), toBeLessThan(OrEqual), toBeCloseTo, toContain, toContainEqual, toMatch, toMatchObject, toHaveLength, toHaveProperty, toBeInstanceOf, toBeType, toBeOneOf, toThrow, toSatisfy, toBeEmpty.

Soft assertions

Collect every failure and report them together:

import { softly } from "two-go";

await softly((expect) => {
  expect(res.status).toBe(200);
  expect(res.get("data")).toHaveLength(2);
});

Schema validation and inference

import { validate } from "two-go/schema";
import { inferSchema } from "two-go";

validate({ id: 1 }, { type: "object", required: ["id"], properties: { id: { type: "integer" } } });

const res = await api.get("/users");
await api.get("/users").expectJsonSchema(res.toSchema());