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start-sdk/lib/esm/deps/deno.land/x/expect@v0.2.9/expect.js
2023-02-27 10:38:56 -07:00

64 lines
2.3 KiB
JavaScript

import * as builtInMatchers from "./matchers.js";
import { AssertionError } from "../../std@0.97.0/testing/asserts.js";
const matchers = {
...builtInMatchers,
};
export function expect(value) {
let isNot = false;
let isPromised = false;
const self = new Proxy({}, {
get(_, name) {
if (name === "not") {
isNot = !isNot;
return self;
}
if (name === "resolves") {
if (!(value instanceof Promise)) {
throw new AssertionError("expected value must be a Promise");
}
isPromised = true;
return self;
}
if (name === "rejects") {
if (!(value instanceof Promise)) {
throw new AssertionError("expected value must be a Promise");
}
value = value.then((value) => {
throw new AssertionError(`Promise did not reject. resolved to ${value}`);
}, (err) => err);
isPromised = true;
return self;
}
const matcher = matchers[name];
if (!matcher) {
throw new TypeError(typeof name === "string"
? `matcher not found: ${name}`
: "matcher not found");
}
return (...args) => {
function applyMatcher(value, args) {
if (isNot) {
let result = matcher(value, ...args);
if (result.pass) {
throw new AssertionError("should not " + result.message);
}
}
else {
let result = matcher(value, ...args);
if (!result.pass) {
throw new AssertionError(result.message || "Unknown error");
}
}
}
return isPromised
? value.then((value) => applyMatcher(value, args))
: applyMatcher(value, args);
};
},
});
return self;
}
export function addMatchers(newMatchers) {
Object.assign(matchers, newMatchers);
}