Convert scripts/Gulpfile to checked mjs/cjs so they can run without compilation (#50988)

scripts/errorCheck.mjs

@@ -0,0 +1,87 @@
+import fs from "fs";
+import fsPromises from "fs/promises";
+import _glob from "glob";
+import util from "util";
+
+const glob = util.promisify(_glob);
+
+async function checkErrorBaselines() {
+    const data = await fsPromises.readFile("src/compiler/diagnosticMessages.json", "utf-8");
+    const messages = JSON.parse(data);
+    const keys = Object.keys(messages);
+    console.log("Loaded " + keys.length + " errors");
+
+    for (const k of keys) {
+        messages[k].seen = false;
+    }
+
+    const errRegex = /\(\d+,\d+\): error TS([^:]+):/g;
+    const baseDir = "tests/baselines/reference/";
+
+    const files = (await fsPromises.readdir(baseDir)).filter(f => f.endsWith(".errors.txt"));
+
+    files.forEach(f => {
+        fs.readFile(baseDir + f, "utf-8", (err, baseline) => {
+            if (err) throw err;
+
+            let g;
+            while (g = errRegex.exec(baseline)) {
+                const errCode = +g[1];
+                const msg = keys.filter(k => messages[k].code === errCode)[0];
+                messages[msg].seen = true;
+            }
+        });
+    });
+
+    console.log("== List of errors not present in baselines ==");
+    let count = 0;
+    for (const k of keys) {
+        if (messages[k].seen !== true) {
+            console.log(k);
+            count++;
+        }
+    }
+    console.log(count + " of " + keys.length + " errors are not in baselines");
+}
+
+async function checkSourceFiles() {
+    const data = await fsPromises.readFile("src/compiler/diagnosticInformationMap.generated.ts", "utf-8");
+
+    const errorRegexp = /\s(\w+): \{ code/g;
+    const errorNames = [];
+    let errMatch;
+    while (errMatch = errorRegexp.exec(data)) {
+        errorNames.push(errMatch[1]);
+    }
+
+    let allSrc = "";
+    const files = await glob("./src/**/*.ts");
+    console.log("Reading " + files.length + " source files");
+    for (const file of files) {
+        if (file.indexOf("diagnosticInformationMap.generated.ts") > 0) {
+            continue;
+        }
+
+        const src = fs.readFileSync(file, "utf-8");
+        allSrc = allSrc + src;
+    }
+
+    console.log("Consumed " + allSrc.length + " characters of source");
+
+    let count = 0;
+    console.log("== List of errors not used in source ==");
+    for (const errName of errorNames) {
+        if (allSrc.indexOf(errName) < 0) {
+            console.log(errName);
+            count++;
+        }
+    }
+    console.log(count + " of " + errorNames.length + " errors are not used in source");
+}
+
+async function main() {
+    await checkErrorBaselines();
+    await checkSourceFiles();
+}
+
+main();