Re-write tests and drop dependency on Chai (#1505)

The Chai testing library is now ECMAScript module only. This could have
provided a good occasion to convert tests from CommonJS modules to ECMAScript
modules, but then, looking into actual tests, many of them used Chai where they
could just have used the basic Node.js `assert` module, and the few tests that
used `expect` did not look more readable thanks to that syntax compared to a
more basic `assert` approach.

Instead of converting test code to ECMAScript modules, this update rather drops
the dependency on Chai, rewriting tests where needed to rather call regular
`assert` functions.

package.json

@@ -42,7 +42,6 @@
     "webidl2": "24.4.1"
   },
   "devDependencies": {
-    "chai": "4.3.10",
     "mocha": "10.3.0",
     "respec": "34.4.0",
     "respec-hljs": "2.1.1",

tests/crawl.js

@@ -30,7 +30,7 @@ async function runWithAnnotatedCrawlData(path, fn) {
 }
 
 if (global.describe && describe instanceof Function) {
-  const { assert } = require('chai');
+  const assert = require('assert');
 
   describe("The crawler", function () {
     this.slow(20000);
@@ -109,7 +109,7 @@ if (global.describe && describe instanceof Function) {
           fallback
         }));
       assert.equal(results[0].title, "Change is the only constant");
-      assert.isUndefined(results[0].error);
+      assert.ifError(results[0].error);
       assert.equal(results[0].refs, "A useful list of refs");
     })
 
@@ -119,7 +119,7 @@ if (global.describe && describe instanceof Function) {
         [{ url, nightly: { url } }],
         { forceLocalFetch: true });
       assert.equal(results[0].title, "[Could not be determined, see error]");
-      assert.include(results[0].error, "Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404");
+      assert(results[0].error.includes("Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404"));
     });
 
     it("reports errors and returns fallback data when possible", async () => {
@@ -132,7 +132,7 @@ if (global.describe && describe instanceof Function) {
           fallback
         });
       assert.equal(results[0].title, "On the Internet, nobody knows you don't exist");
-      assert.include(results[0].error, "Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404");
+      assert(results[0].error.includes("Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404"));
       assert.equal(results[0].refs, "A useful list of refs");
     });
 
@@ -147,7 +147,7 @@ if (global.describe && describe instanceof Function) {
       });
       const results = require(path.resolve(output, "index.json"));
       assert.equal(results.results[0].url, "https://www.w3.org/TR/idontexist/");
-      assert.include(results.results[0].error, "Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404");
+      assert(results.results[0].error.includes("Loading https://www.w3.org/TR/idontexist/ triggered HTTP status 404"));
       assert.equal(results.results[0].refs, "refs/idontexist.json");
       const refs = require(path.resolve(output, "refs", "idontexist.json"));
       assert.equal(refs.refs, "A useful list of refs");
@@ -159,7 +159,7 @@ if (global.describe && describe instanceof Function) {
         [{ url, nightly: { url } }],
         { forceLocalFetch: true });
       assert.equal(results[0].title, "[Could not be determined, see error]");
-      assert.include(results[0].error, "CSS server issue detected");
+      assert(results[0].error.includes("CSS server issue detected"));
     });
 
     it("crawls the published spec when `--release` is set", async () => {

tests/create-outline.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/css-grammar-parser/test.js

@@ -1,6 +1,6 @@
 const css = require("../../src/lib/css-grammar-parser");
 const fs = require("fs");
-const expect = require('chai').expect;
+const assert = require("assert");
 
 const propDefs = fs.readFileSync("tests/css-grammar-parser/in", "utf-8").split("\n").map(def => def.trim());
 const propDefsOut = JSON.parse(fs.readFileSync("tests/css-grammar-parser/out.json", "utf-8"));
@@ -9,7 +9,7 @@ const results = propDefs.map(css.parsePropDefValue);
 describe('Parser correctly parses grammar instances', () => {
   for(let i in results) {
     it(`parses property definition ${propDefs[i]} as expected`, () => {
-      expect(results[i]).to.deep.equal(propDefsOut[i], `Parsing ${propDefs[i]} got ${JSON.stringify(results[i], null, 2)} instead of ${JSON.stringify(propDefsOut[i], null, 2)}`);
+      assert.deepStrictEqual(results[i], propDefsOut[i], `Parsing ${propDefs[i]} got ${JSON.stringify(results[i], null, 2)} instead of ${JSON.stringify(propDefsOut[i], null, 2)}`);
     });
   }
 });

tests/extract-dfns.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/extract-events.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/extract-headings.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/extract-ids.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/extract-references.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');

tests/extract-webidl.js

@@ -1,4 +1,4 @@
-const { assert } = require('chai');
+const assert = require('assert');
 const puppeteer = require('puppeteer');
 const path = require('path');
 const rollup = require('rollup');