validateParams: add test

Author: xr0master

test/utils/validate_params_test.dart

@@ -0,0 +1,59 @@
+import 'package:emailjs/src/utils/validate_params.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('should fail on the public key', () {
+    test('no key', () {
+      expect(
+        () => validateParams('', 'default_service', 'my_test_template'),
+        throwsA(startsWith('The public key is required')),
+      );
+    });
+
+    test('no string', () {
+      expect(
+        () => validateParams(null, 'default_service', 'my_test_template'),
+        throwsA(startsWith('The public key is required')),
+      );
+    });
+  });
+
+  group('should fail on the service ID', () {
+    test('no key', () {
+      expect(
+        () => validateParams('d2JWGTestKeySomething', '', 'my_test_template'),
+        throwsA(startsWith('The service ID is required')),
+      );
+    });
+
+    test('no string', () {
+      expect(
+        () => validateParams('d2JWGTestKeySomething', null, 'my_test_template'),
+        throwsA(startsWith('The service ID is required')),
+      );
+    });
+  });
+
+  group('should fail on the service ID', () {
+    test('no key', () {
+      expect(
+        () => validateParams('d2JWGTestKeySomething', 'default_service', ''),
+        throwsA(startsWith('The template ID is required')),
+      );
+    });
+
+    test('no string', () {
+      expect(
+        () => validateParams('d2JWGTestKeySomething', 'default_service', null),
+        throwsA(startsWith('The template ID is required')),
+      );
+    });
+  });
+
+  test('should successfully pass the validation', () {
+    expect(
+      () => validateParams('d2JWGTestKeySomething', 'default_service', 'my_test_template'),
+      returnsNormally,
+    );
+  });
+}