Mock bcryptjs in API tests

services/api/__mocks__/bcryptjs.js

@@ -0,0 +1,10 @@
+// Real bcrypt at the production cost of 12 takes ~200ms per hash or compare,
+// which dominates the auth tests. 4 is the minimum cost bcrypt accepts.
+
+const { default: bcrypt } = await vi.importActual('bcryptjs');
+
+function genSalt() {
+  return bcrypt.genSalt(4);
+}
+
+export default { ...bcrypt, genSalt };

services/api/src/utils/testing/setup/mocks.js

@@ -1,6 +1,7 @@
 // Replaces these packages with their counterparts in __mocks__.
 vi.mock('@google-cloud/storage');
 vi.mock('@simplewebauthn/server');
+vi.mock('bcryptjs');
 vi.mock('firebase-admin');
 vi.mock('google-auth-library');
 vi.mock('postmark');