Clone engine262 in /engine262

engine262/test/stepped.js

@@ -0,0 +1,66 @@
+'use strict';
+
+require('@snek/source-map-support/register');
+const {
+  isMainThread, parentPort, workerData, Worker,
+} = require('worker_threads');
+const fs = require('fs');
+// eslint-disable-next-line import/no-extraneous-dependencies
+const { codeFrameColumns } = require('@babel/code-frame');
+
+if (isMainThread) {
+  const shared = new SharedArrayBuffer(4);
+  const shared32 = new Int32Array(shared);
+  const source = fs.readFileSync(process.argv[2], 'utf8');
+  const worker = new Worker(__filename, {
+    workerData: { shared, source },
+  });
+  process.stdin.on('data', () => {
+    const old = Atomics.compareExchange(shared32, 0, 0, 1);
+    if (old === 0) {
+      Atomics.notify(shared32, 0, 1);
+    }
+  });
+  worker.on('message', (data) => {
+    const node = JSON.parse(data);
+    const frame = codeFrameColumns(source, node.location, {
+      highlightCode: true,
+      message: node.type,
+    });
+    process.stdout.write(`${frame}\n\n\n`);
+  });
+  worker.on('exit', () => {
+    process.exit(0);
+  });
+} else {
+  const {
+    Agent,
+    setSurroundingAgent,
+    ManagedRealm,
+    AbruptCompletion,
+    inspect,
+  } = require('..');
+
+  const shared32 = new Int32Array(workerData.shared);
+  setSurroundingAgent(new Agent({
+    onNodeEvaluation(node) {
+      if (node.type === 'ExpressionStatement') {
+        return;
+      }
+      parentPort.postMessage(JSON.stringify(node));
+      Atomics.wait(shared32, 0, 0);
+      Atomics.store(shared32, 0, 0);
+    },
+  }));
+
+  const realm = new ManagedRealm();
+
+  realm.scope(() => {
+    const completion = realm.evaluateScript(workerData.source);
+    if (completion instanceof AbruptCompletion) {
+      process.stdout.write(`${inspect(completion, realm)}\n`);
+    }
+  });
+
+  process.exit(0);
+}