feat: allow calling parseStack with string

Author: joshunrau

src/__tests__/exception.test.ts

@@ -1,7 +1,7 @@
 import type { Simplify } from 'type-fest';
 import { describe, expect, expectTypeOf, it, test } from 'vitest';
 
-import { BaseException, ExceptionBuilder, OutOfRangeException, ValueException } from '../exception.js';
+import { BaseException, ExceptionBuilder, OutOfRangeException, parseStack, ValueException } from '../exception.js';
 import { Err } from '../vendor/neverthrow.js';
 
 import type { ExceptionConstructor } from '../exception.js';
@@ -189,3 +189,12 @@ describe('OutOfRangeException', () => {
     });
   });
 });
+
+describe('parseStack', () => {
+  it('should return the same value, in terms of value, whether called with an error or a string', () => {
+    const error = new Error();
+    const r1 = parseStack(error);
+    const r2 = parseStack(error.stack!);
+    expect(r1).toStrictEqual(r2);
+  });
+});

src/exception.ts

@@ -63,8 +63,11 @@ interface ExceptionLike extends Error, ExceptionOptions {
   toString(): string;
 }
 
-function parseStack(error: Error): string[] {
-  return extractStack.lines(cleanStack(error.stack, { pretty: true }));
+function parseStack(stack: string | undefined): string[];
+function parseStack(error: Error): string[];
+function parseStack(errorOrStack: Error | string | undefined): string[] {
+  const stack = typeof errorOrStack === 'string' ? errorOrStack : errorOrStack?.stack;
+  return extractStack.lines(cleanStack(stack, { pretty: true }));
 }
 
 abstract class BaseException<TParams extends ExceptionParams, TOptions extends ExceptionOptions>