Support tracking requires

Signed-off-by: Darshan Sen <[email protected]>

index.js

@@ -32,4 +32,25 @@ class TraceEvents {
   }
 }
 
-module.exports = { TraceEvents };
+// Monkey patching require().
+// Refs: https://stackoverflow.com/a/42883538
+const Module = require('module');
+const originalRequire = Module.prototype.require;
+
+function trackRequires(shouldTrackRequires) {
+  if (shouldTrackRequires) {
+    Module.prototype.require = function () {
+      performance.mark(`require("${arguments[0]}")`);
+      const ret = originalRequire.apply(this, arguments);
+      performance.measure(`require("${arguments[0]}")`, `require("${arguments[0]}")`);
+      return ret;
+    };
+  } else {
+    Module.prototype.require = originalRequire;
+  }
+}
+
+module.exports = {
+  TraceEvents,
+  trackRequires,
+};

test/test.js

@@ -1,5 +1,5 @@
 const { ok } = require("node:assert");
-const { TraceEvents } = require("..");
+const { TraceEvents, trackRequires } = require("..");
 const { after, before, describe, test } = require("node:test");
 const { performance } = require("node:perf_hooks");
 
@@ -65,3 +65,30 @@ describe("interleaved events", async () => {
     traceEvents.destroy();
   });
 });
+
+describe("track requires", async () => {
+  let traceEvents;
+
+  await before(async () => {
+    traceEvents = new TraceEvents();
+    console.log(traceEvents);
+    trackRequires(true);
+    require("node:tls");
+    trackRequires(false);
+    require("node:net");
+
+    return new Promise((resolve, reject) => setImmediate(resolve));
+  });
+
+  test("find events", () => {
+    const events = traceEvents.getEvents();
+    const requireTls = events.find((element) => element.name === `require("node:tls")`);
+    ok(requireTls);
+    const requireNet = events.find((element) => element.name === `require("node:net")`);
+    ok(!requireNet);
+  });
+
+  after(() => {
+    traceEvents.destroy();
+  });
+});