fix: capture async stack only for rejections with native error objects; (#6203)

lib/core/Axios.js

@@ -39,17 +39,20 @@ class Axios {
     try {
       return await this._request(configOrUrl, config);
     } catch (err) {
-      const dummy = {}
-      if (Error.captureStackTrace) {
-        Error.captureStackTrace(dummy)
-      } else {
-        dummy.stack = new Error().stack;
-      }
-      // slice off the Error: ... line
-      dummy.stack = dummy.stack.replace(/^.+\n/, '');
-      // match without the 2 top stack lines
-      if (!err.stack.endsWith(dummy.stack.replace(/^.+\n.+\n/, ''))) {
-        err.stack += '\n' + dummy.stack
+      if (err instanceof Error) {
+        let dummy;
+
+        Error.captureStackTrace ? Error.captureStackTrace(dummy = {}) : (dummy = new Error());
+
+        // slice off the Error: ... line
+        const stack = dummy.stack ? dummy.stack.replace(/^.+\n/, '') : '';
+
+        if (!err.stack) {
+          err.stack = stack;
+          // match without the 2 top stack lines
+        } else if (stack && !String(err.stack).endsWith(stack.replace(/^.+\n.+\n/, ''))) {
+          err.stack += '\n' + stack
+        }
       }
 
       throw err;

test/unit/adapters/http.js

@@ -449,28 +449,29 @@ describe('supports http with nodejs', function () {
     });
   });
 
-  it('should wrap HTTP errors and keep stack', function (done) {
+  it('should wrap HTTP errors and keep stack', async function () {
     if (nodeMajorVersion <= 12) {
       this.skip(); // node 12 support for async stack traces appears lacking
       return;
     }
-    server = http.createServer(function (req, res) {
+
+    server = await startHTTPServer((req, res) => {
       res.statusCode = 400;
       res.end();
-    }).listen(4444, function () {
-      void assert.rejects(
-        async function findMeInStackTrace() {
-          await axios.head('http://localhost:4444/one')
-        },
-        function (err) {
-          assert.equal(err.name, 'AxiosError')
-          assert.equal(err.isAxiosError, true)
-          const matches = [...err.stack.matchAll(/findMeInStackTrace/g)]
-          assert.equal(matches.length, 1, err.stack)
-          return true;
-        }
-    ).then(done).catch(done);
     });
+
+    return assert.rejects(
+      async function findMeInStackTrace() {
+        await axios.head('http://localhost:4444/one')
+      },
+      function (err) {
+        assert.equal(err.name, 'AxiosError')
+        assert.equal(err.isAxiosError, true)
+        const matches = [...err.stack.matchAll(/findMeInStackTrace/g)]
+        assert.equal(matches.length, 1, err.stack)
+        return true;
+      }
+    )
   });
 
   it('should wrap interceptor errors and keep stack', function (done) {