test(19-01): add failing tests for hashPassword/verifyPassword scrypt primitives

apps/api/tests/auth/localCredentials.test.ts

@@ -0,0 +1,57 @@
+/**
+ * localCredentials.ts — unit tests for hashPassword / verifyPassword.
+ *
+ * Uses node:crypto scrypt under the hood; no external dependencies.
+ * All tests run without MariaDB or any external service.
+ *
+ * Test suite (TDD RED → GREEN — Plan 19-01 Task 1):
+ *   Test 1: correct password verifies true
+ *   Test 2: wrong password verifies false
+ *   Test 3: two hashes of the same input produce different encoded strings (unique salt)
+ *   Test 4: verifyPassword never throws on a malformed hash (returns false)
+ *   Test 5: encoded string has the PHC shape: scrypt$N$r$p$<salt_b64url>$<hash_b64url> (6 segments)
+ */
+
+import { describe, it, expect } from 'vitest';
+import { hashPassword, verifyPassword } from '../../src/auth/localCredentials.js';
+
+describe('hashPassword / verifyPassword', () => {
+  it('Test 1: verifyPassword(hashPassword(pw), pw) === true (round-trip)', () => {
+    const encoded = hashPassword('hunter2');
+    const result = verifyPassword(encoded, 'hunter2');
+    expect(result).toBe(true);
+  });
+
+  it('Test 2: verifyPassword(hashPassword(pw), wrong) === false', () => {
+    const encoded = hashPassword('hunter2');
+    const result = verifyPassword(encoded, 'wrong-password');
+    expect(result).toBe(false);
+  });
+
+  it('Test 3: two hashPassword calls on same input produce different encoded strings (unique salt)', () => {
+    const encoded1 = hashPassword('x');
+    const encoded2 = hashPassword('x');
+    expect(encoded1).not.toBe(encoded2);
+  });
+
+  it('Test 4: verifyPassword returns false (never throws) on a malformed stored hash', () => {
+    expect(() => verifyPassword('not-a-valid-hash', 'x')).not.toThrow();
+    expect(verifyPassword('not-a-valid-hash', 'x')).toBe(false);
+    expect(verifyPassword('', 'x')).toBe(false);
+    expect(verifyPassword('scrypt$bad$data', 'x')).toBe(false);
+  });
+
+  it('Test 5: encoded string has scrypt$N$r$p$salt$hash shape (6 $-delimited segments)', () => {
+    const encoded = hashPassword('testpassword');
+    const segments = encoded.split('$');
+    expect(segments).toHaveLength(6);
+    expect(segments[0]).toBe('scrypt');
+    // N, r, p are numeric
+    expect(Number(segments[1])).toBeGreaterThan(0); // N
+    expect(Number(segments[2])).toBeGreaterThan(0); // r
+    expect(Number(segments[3])).toBeGreaterThan(0); // p
+    // salt and hash are non-empty base64url strings
+    expect(segments[4].length).toBeGreaterThan(0);
+    expect(segments[5].length).toBeGreaterThan(0);
+  });
+});