Merge pull request #4 from skillbox-koutja/fixes

Fixes

README.md

@@ -177,7 +177,7 @@ final validator = Verify.inOrder<SignUpFormState>([
 
 final Map<FormField, SignUpError> errorMap = validator
     .verify<SignUpError>(someState)
-    .groupedErrorsBy((error) => error.field);
+    .errorsGroupedBy((error) => error.field);
 ```
 
 ## Sequencing

example/lib/bloc/signup/signup_bloc.dart

@@ -26,7 +26,7 @@ class SignUpBloc extends Bloc<SignUpEvent, SignUpState> {
 
     final errors = signUpValidation
         .verify<SignUpError>(newState)
-        .groupedErrorsBy((error) => error.field)
+        .errorsGroupedBy((error) => error.field)
         .messages;
 
     yield newState.copyWith(errors: errors);

example/lib/bloc/signup/signup_validation.dart

@@ -2,22 +2,22 @@ import 'package:verify/verify.dart';
 import 'package:verify_example/bloc/signup/signup_bloc.dart';
 import 'package:verify_example/bloc/signup/signup_error.dart';
 
-final Validator_<SignUpState> signUpValidation = Verify.all<SignUpState>([
+final Validator<SignUpState> signUpValidation = Verify.all<SignUpState>([
   Verify.subject<SignUpState>().checkField(
       (state) => state.password,
-      Verify.property<String?>((s) => s != null && s.length > 4,
+      Verify.that<String?>((s) => s != null && s.length > 4,
           error: SignUpError(
             field: SignUpFormField.password,
             message: 'incorrect length',
           ))),
   Verify.subject<SignUpState>().checkField(
       (state) => state.email,
-      Verify.property<String?>((s) => s?.contains('@') ?? false,
+      Verify.that<String?>((s) => s?.contains('@') ?? false,
           error: SignUpError(
             field: SignUpFormField.email,
             message: 'invalid format',
           ))),
-  Verify.property((SignUpState state) => state.confirmation == state.password,
+  Verify.that((SignUpState state) => state.confirmation == state.password,
       error: SignUpError(
         field: SignUpFormField.passwordConfirmation,
         message: 'not match',

lib/src/extensions.dart

@@ -1,16 +1,16 @@
 import 'package:dartz/dartz.dart';
 
-import 'base_types.dart';
+import 'package:verify/src/base_types.dart';
 
 /// Extensions to facilitate manipulating validation results.
 extension ValidationResult<T, E extends ValidationError> on Either<List<E>, T> {
   /// Gets the first error according to the composition sequence used
   /// creating of calling validation result
   E? get firstError {
-    return fold((errors) => errors.first, (_) => null);
+    return fold((errors) => errors.isEmpty ? null : errors.first , (_) => null);
   }
 
-  /// Returns a map of grouped validatiton errors keyed by a formfield type.
+  /// Returns a map of grouped validation errors keyed by a formfield type.
   ///
   /// The provided selector must be a the field in the provided error that uniquely
   /// identifies the corresponding form field.

lib/src/verify.dart

@@ -84,7 +84,8 @@ extension ValidatorUtils<S, T> on ValidatorT<S, T> {
   ErrorType? firstError<ErrorType>(S subject) {
     return this(subject).leftMap((errors) {
       final Iterable<ErrorType> filtered = errors.whereType();
-      return filtered.toList().first;
+      final list = filtered.toList();
+      return list.isEmpty ? null : list.first;
     }).fold((l) => l, (r) => null);
   }
 

lib/src/verify_factories.dart

@@ -4,7 +4,7 @@ part of 'verify.dart';
 ///
 /// All the methods in this scope are static
 extension Verify on ValidatorT {
-  /// Creates an always succeding validator
+  /// Creates an always succeeding validator
   ///
   /// Ignores input and always returns the provided value.
   static Validator<S> valid<S>(S subject) {

test/verify_test.dart

@@ -8,13 +8,6 @@ import 'data/error.dart';
 import 'data/product_error.dart';
 import 'data/user.dart';
 
-class ValidateString {
-  static Validator<String> length(int length,
-      {required ValidationError error}) {
-    return Verify.that((s) => s.length == length, error: error);
-  }
-}
-
 void main() {
   final listEquality = const ListEquality().equals;
 
@@ -131,7 +124,7 @@ void main() {
     assert(result.isLeft());
   });
 
-  test('Can create and run an always succeding validator', () {
+  test('Can create and run an always succeeding validator', () {
     final validator = Verify.valid(tUserGood);
     final result = validator.verify(tUserBad);
     assert(result.isRight());
@@ -211,7 +204,7 @@ void main() {
   });
 
   test(
-      'performing a succeding check on a failing validator returns a single value error list',
+      'performing a succeeding check on a failing validator returns a single value error list',
       () {
     final parentError = Error('some errror');
     const tUser = User('', '', 10);