Do not throw on custom stack traces

source/core/index.ts

@@ -1222,7 +1222,7 @@ export class RequestError extends Error {
 		this.timings = this.request?.timings;
 
 		// Recover the original stacktrace
-		if (!is.undefined(error.stack)) {
+		if (is.string(error.stack) && is.string(this.stack)) {
 			const indexOfMessage = this.stack.indexOf(this.message) + this.message.length;
 			const thisStackTrace = this.stack.slice(indexOfMessage).split('\n').reverse();
 			const errorStackTrace = error.stack.slice(error.stack.indexOf(error.message!) + error.message!.length).split('\n').reverse();

test/error.ts

@@ -3,6 +3,8 @@ import net = require('net');
 import http = require('http');
 import stream = require('stream');
 import test from 'ava';
+import getStream = require('get-stream');
+import is from '@sindresorhus/is';
 import got, {RequestError, HTTPError, TimeoutError} from '../source';
 import withServer from './helpers/with-server';
 
@@ -261,3 +263,70 @@ test.skip('the old stacktrace is recovered', async t => {
 	// the second `at get` points to the real cause.
 	t.not(error.stack!.indexOf('at get'), error.stack!.lastIndexOf('at get'));
 });
+
+test.serial('custom stack trace', withServer, async (t, _server, got) => {
+	const ErrorCaptureStackTrace = Error.captureStackTrace;
+
+	const enable = () => {
+		Error.captureStackTrace = (target: {stack: any}) => {
+			target.stack = [
+				'line 1',
+				'line 2'
+			];
+		};
+	};
+
+	const disable = () => {
+		Error.captureStackTrace = ErrorCaptureStackTrace;
+	};
+
+	// Node.js default behavior
+	{
+		const stream = got.stream('');
+		stream.destroy(new Error('oh no'));
+
+		const caught = await t.throwsAsync(getStream(stream));
+		t.is(is(caught.stack), 'string');
+	}
+
+	// Passing a custom error
+	{
+		enable();
+		const error = new Error('oh no');
+		disable();
+
+		const stream = got.stream('');
+		stream.destroy(error);
+
+		const caught = await t.throwsAsync(getStream(stream));
+		t.is(is(caught.stack), 'string');
+	}
+
+	// Custom global behavior
+	{
+		enable();
+		const error = new Error('oh no');
+
+		const stream = got.stream('');
+		stream.destroy(error);
+
+		const caught = await t.throwsAsync(getStream(stream));
+		t.is(is(caught.stack), 'Array');
+
+		disable();
+	}
+
+	// Passing a default error that needs some processing
+	{
+		const error = new Error('oh no');
+		enable();
+
+		const stream = got.stream('');
+		stream.destroy(error);
+
+		const caught = await t.throwsAsync(getStream(stream));
+		t.is(is(caught.stack), 'Array');
+
+		disable();
+	}
+});