add missing unit test suite

tests/git-basic-auth-header.test.ts

@@ -0,0 +1,35 @@
+/**
+ * Regression test for #1273 — HTTPS token auth with an empty username.
+ *
+ * A token credential with a blank username produced a Basic header of
+ * base64(":token"). GitHub rejects that with 401 and git falls back to an
+ * interactive prompt, dying with "could not read Username ... terminal prompts
+ * disabled". buildBasicAuthHeader must default an empty username to a non-empty
+ * placeholder (`x-access-token`) so GitHub accepts the header.
+ */
+import { describe, test, expect } from 'bun:test';
+import { buildBasicAuthHeader } from '../src/lib/server/git-auth';
+
+function decode(header: string): string {
+	const b64 = header.replace(/^Authorization: Basic /, '');
+	return Buffer.from(b64, 'base64').toString('utf8');
+}
+
+describe('buildBasicAuthHeader (#1273)', () => {
+	test('empty username defaults to x-access-token (not base64(":token"))', () => {
+		const header = buildBasicAuthHeader('', 'ghp_sometoken');
+		// The bug: empty username → "..:token". The fix: "x-access-token:token".
+		expect(decode(header)).toBe('x-access-token:ghp_sometoken');
+		expect(decode(header).startsWith(':')).toBe(false);
+	});
+
+	test('a user-supplied username is preserved', () => {
+		const header = buildBasicAuthHeader('user', 'ghp_sometoken');
+		expect(decode(header)).toBe('user:ghp_sometoken');
+	});
+
+	test('produces a well-formed Basic Authorization header', () => {
+		const header = buildBasicAuthHeader('x-access-token', 'tok');
+		expect(header).toBe(`Authorization: Basic ${Buffer.from('x-access-token:tok').toString('base64')}`);
+	});
+});