meta: add a --parallel flag to the runner for faster local testing (#21140)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

scripts/p-limit.mjs

@@ -0,0 +1,109 @@
+/**
+ * p-limit@6.2.0
+ * https://github.com/sindresorhus/p-limit
+ * MIT (c) Sindre Sorhus
+ */
+
+import Queue from "./yocto-queue.mjs";
+
+export default function pLimit(concurrency) {
+  validateConcurrency(concurrency);
+
+  const queue = new Queue();
+  let activeCount = 0;
+
+  const resumeNext = () => {
+    if (activeCount < concurrency && queue.size > 0) {
+      queue.dequeue()();
+      // Since `pendingCount` has been decreased by one, increase `activeCount` by one.
+      activeCount++;
+    }
+  };
+
+  const next = () => {
+    activeCount--;
+
+    resumeNext();
+  };
+
+  const run = async (function_, resolve, arguments_) => {
+    const result = (async () => function_(...arguments_))();
+
+    resolve(result);
+
+    try {
+      await result;
+    } catch {}
+
+    next();
+  };
+
+  const enqueue = (function_, resolve, arguments_) => {
+    // Queue `internalResolve` instead of the `run` function
+    // to preserve asynchronous context.
+    new Promise(internalResolve => {
+      queue.enqueue(internalResolve);
+    }).then(run.bind(undefined, function_, resolve, arguments_));
+
+    (async () => {
+      // This function needs to wait until the next microtask before comparing
+      // `activeCount` to `concurrency`, because `activeCount` is updated asynchronously
+      // after the `internalResolve` function is dequeued and called. The comparison in the if-statement
+      // needs to happen asynchronously as well to get an up-to-date value for `activeCount`.
+      await Promise.resolve();
+
+      if (activeCount < concurrency) {
+        resumeNext();
+      }
+    })();
+  };
+
+  const generator = (function_, ...arguments_) =>
+    new Promise(resolve => {
+      enqueue(function_, resolve, arguments_);
+    });
+
+  Object.defineProperties(generator, {
+    activeCount: {
+      get: () => activeCount,
+    },
+    pendingCount: {
+      get: () => queue.size,
+    },
+    clearQueue: {
+      value() {
+        queue.clear();
+      },
+    },
+    concurrency: {
+      get: () => concurrency,
+
+      set(newConcurrency) {
+        validateConcurrency(newConcurrency);
+        concurrency = newConcurrency;
+
+        queueMicrotask(() => {
+          // eslint-disable-next-line no-unmodified-loop-condition
+          while (activeCount < concurrency && queue.size > 0) {
+            resumeNext();
+          }
+        });
+      },
+    },
+  });
+
+  return generator;
+}
+
+export function limitFunction(function_, option) {
+  const { concurrency } = option;
+  const limit = pLimit(concurrency);
+
+  return (...arguments_) => limit(() => function_(...arguments_));
+}
+
+function validateConcurrency(concurrency) {
+  if (!((Number.isInteger(concurrency) || concurrency === Number.POSITIVE_INFINITY) && concurrency > 0)) {
+    throw new TypeError("Expected `concurrency` to be a number from 1 and up");
+  }
+}