From 847b05b2232d684db4eda8e175b3d5b286c2b5b8 Mon Sep 17 00:00:00 2001
From: Jackson Weber <jacksonweber@microsoft.com>
Date: Tue, 24 Mar 2026 14:49:54 -0700
Subject: [PATCH] Update stack frame parsing for exceptions.

---
 src/logs/exceptions.ts                  | 11 +++++-
 test/unitTests/logs/exceptions.tests.ts | 48 ++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/src/logs/exceptions.ts b/src/logs/exceptions.ts
index d98c8045d..54c7032ed 100644
--- a/src/logs/exceptions.ts
+++ b/src/logs/exceptions.ts
@@ -91,6 +91,8 @@ export class AutoCollectExceptions {
 // regex to match stack frames from ie/chrome/ff
 // methodName=$2, fileName=$4, lineNo=$5, column=$6
 const stackFramesRegex = /^(\s+at)?(.*?)(\@|\s\(|\s)([^\(\n]+):(\d+):(\d+)(\)?)$/;
+// regex to match native/built-in frames with no file location, e.g. "    at Array.forEach ()" or "    at Array.forEach (<anonymous>)"
+const nativeFrameRegex = /^\s+at\s+(.+?)\s+\((<anonymous>|native)?\)$/;
 
 export class _StackFrame {
     public sizeInBytes = 0;
@@ -111,6 +113,13 @@ export class _StackFrame {
             this.method = Util.getInstance().trim(matches[2]) || this.method;
             this.fileName = Util.getInstance().trim(matches[4]) || "<no_filename>";
             this.line = parseInt(matches[5]) || 0;
+        } else {
+            const nativeMatches = frame.match(nativeFrameRegex);
+            if (nativeMatches) {
+                this.method = Util.getInstance().trim(nativeMatches[1]) || this.method;
+                this.fileName = "<no_filename>";
+                this.line = 0;
+            }
         }
 
         this.sizeInBytes += this.method.length;
@@ -134,7 +143,7 @@ export function parseStack(stack: any): _StackFrame[] {
         let totalSizeInBytes = 0;
         for (let i = 0; i <= frames.length; i++) {
             const frame = frames[i];
-            if (stackFramesRegex.test(frame)) {
+            if (stackFramesRegex.test(frame) || nativeFrameRegex.test(frame)) {
                 const parsedFrame = new _StackFrame(frames[i], level++);
                 totalSizeInBytes += parsedFrame.sizeInBytes;
                 parsedStack.push(parsedFrame);
diff --git a/test/unitTests/logs/exceptions.tests.ts b/test/unitTests/logs/exceptions.tests.ts
index 92c1b2fb0..fd3f2e31e 100644
--- a/test/unitTests/logs/exceptions.tests.ts
+++ b/test/unitTests/logs/exceptions.tests.ts
@@ -3,7 +3,7 @@
 import assert from "assert";
 import sinon from "sinon";
 
-import { AutoCollectExceptions } from "../../../src/logs/exceptions";
+import { AutoCollectExceptions, _StackFrame, parseStack } from "../../../src/logs/exceptions";
 
 describe("AutoCollection/Exceptions", () => {
     let sandbox: sinon.SinonSandbox;
@@ -41,3 +41,49 @@ describe("AutoCollection/Exceptions", () => {
         assert.equal(processRemoveListenerSpy.getCall(1).args[0], "unhandledRejection");
     });
 });
+
+describe("StackFrame Parsing", () => {
+    it("should parse standard stack frames", () => {
+        const frame = new _StackFrame("    at Object.<anonymous> (/path/to/file.js:10:5)", 0);
+        assert.equal(frame.method, "Object.<anonymous>");
+        assert.equal(frame.fileName, "/path/to/file.js");
+        assert.equal(frame.line, 10);
+    });
+
+    it("should parse native frames with empty parens (issue #698)", () => {
+        const frame = new _StackFrame("    at Array.forEach ()", 0);
+        assert.equal(frame.method, "Array.forEach");
+        assert.equal(frame.fileName, "<no_filename>");
+        assert.equal(frame.line, 0);
+    });
+
+    it("should parse native frames with <anonymous>", () => {
+        const frame = new _StackFrame("    at Array.forEach (<anonymous>)", 0);
+        assert.equal(frame.method, "Array.forEach");
+        assert.equal(frame.fileName, "<no_filename>");
+        assert.equal(frame.line, 0);
+    });
+
+    it("should parse native frames with native keyword", () => {
+        const frame = new _StackFrame("    at Array.forEach (native)", 0);
+        assert.equal(frame.method, "Array.forEach");
+        assert.equal(frame.fileName, "<no_filename>");
+        assert.equal(frame.line, 0);
+    });
+
+    it("parseStack should include native frames in parsed output", () => {
+        const stack = [
+            "Error: test",
+            "    at Object.<anonymous> (/path/to/file.js:10:5)",
+            "    at Array.forEach ()",
+            "    at Module._compile (internal/modules/cjs/loader.js:778:30)",
+        ].join("\n");
+
+        const parsed = parseStack(stack);
+        assert.equal(parsed.length, 3);
+        assert.equal(parsed[0].method, "Object.<anonymous>");
+        assert.equal(parsed[1].method, "Array.forEach");
+        assert.equal(parsed[1].fileName, "<no_filename>");
+        assert.equal(parsed[2].method, "Module._compile");
+    });
+});