test: unit tests for promises.ts

Author: mini-bomba

test/arrays.test.ts

@@ -1,7 +1,5 @@
 import { chunkArray, zip } from "../lib/arrays.ts";
 
-const expect = chai.expect;
-
 describe("arrays.ts", () => {
   describe("chunkArray", () => {
     it("12-length array with chunk size 4 => 3x4-element array output", () => {

test/map.test.ts

@@ -1,7 +1,5 @@
 import { ExtendedMap, extendGlobally, extendMap } from "../lib/map.ts";
 
-const expect = chai.expect;
-
 describe("map.ts", () => {
   describe("ExtendedMap", () => {
     it("basic map functionality", () => {

test/promises.test.ts

@@ -0,0 +1,15 @@
+import { wait } from "../lib/promises.ts";
+
+describe("promises.ts", () => {
+  describe("wait", function () {
+    this.timeout(1000);
+    this.slow(500);
+
+    it("resolves after the given amount of time", async () => {
+      const start = performance.now();
+      await expect(wait(201)).to.eventually.equal(undefined);
+      const elapsed = performance.now() - start;
+      expect(elapsed).to.be.greaterThanOrEqual(200);
+    });
+  });
+});

test/semaphore.test.ts

@@ -1,7 +1,5 @@
 import { Semaphore } from "../lib/semaphore.ts";
 
-const expect = chai.expect;
-
 describe("semaphore.ts", () => {
   // a semaphore class with public acquire/release methods for testing
   class OpenSemaphore extends Semaphore {

test/support/setup.ts

@@ -5,7 +5,10 @@ import spies from "chai-spies";
 declare global {
   // eslint-disable-next-line vars-on-top, no-var
   var chai: Chai.ChaiStatic;
+  // eslint-disable-next-line vars-on-top, no-var
+  var expect: Chai.ExpectStatic;
 }
 
 globalThis.chai = use(chaiAsPromised);
 globalThis.chai = chai.use(spies);
+globalThis.expect = chai.expect;