From 430cb04d27bd857a2cd7d3a3191ffa5d33200dd9 Mon Sep 17 00:00:00 2001
From: Konstantin Pelz <Konstantin.pelz@posteo.de>
Date: Tue, 21 Dec 2021 11:47:51 +0100
Subject: [PATCH] #150 add String.isNullOrBlank and String.isNotNullOrBlank

---
 README.md             | 24 ++++++++++++++++++++++++
 lib/src/string.dart   | 10 ++++++++++
 test/string_test.dart | 16 ++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/README.md b/README.md
index 1722ed9..8148a50 100644
--- a/README.md
+++ b/README.md
@@ -207,6 +207,30 @@ final isBlank = ' '.isNullOrEmpty; // false
 final isLineBreak = '\n'.isNullOrEmpty; // false
 ```
 
+### .isNullOrBlank
+
+Returns `true` if the String is either `null` or blank.
+
+```dart
+final isNull = null.isNullOrBlank; // true
+final isEmpty = ''.isNullOrBlank; // true
+final isBlank = ' '.isNullOrBlank; // true
+final isLineBreak = '\n'.isNullOrBlank; // true
+final isFoo = ' foo '.isNullOrBlank; // false
+```
+
+### .isNotNullOrBlank
+
+Returns `true` if the String is neither `null` nor blank.
+
+```dart
+final isNull = null.isNullOrBlank; // true
+final isEmpty = ''.isNullOrBlank; // true
+final isBlank = ' '.isNullOrBlank; // true
+final isLineBreak = '\n'.isNullOrBlank; // true
+final isFoo = ' foo '.isNullOrBlank; // true
+```
+
 ### .isUpperCase
 
 Returns `true` if the entire string is upper case.
diff --git a/lib/src/string.dart b/lib/src/string.dart
index 47fa254..1f2d561 100644
--- a/lib/src/string.dart
+++ b/lib/src/string.dart
@@ -254,3 +254,13 @@ extension NullableStringIsNotNullOrEmptyExtension on String? {
   /// Returns `true` if the string is neither null nor empty.
   bool get isNotNullOrEmpty => !isNullOrEmpty;
 }
+
+extension NullableStringIsNullOrBlankExtension on String? {
+  /// Returns `true` if the string is either `null` or blank.
+  bool get isNullOrBlank => this?.isBlank ?? true;
+}
+
+extension NullableStringIsNotNullOrBlankExtension on String? {
+  /// Returns `true` if the string is neither null nor blank.
+  bool get isNotNullOrBlank => !isNullOrBlank;
+}
diff --git a/test/string_test.dart b/test/string_test.dart
index 6a5aed5..a2d0e49 100644
--- a/test/string_test.dart
+++ b/test/string_test.dart
@@ -161,6 +161,22 @@ void main() {
       expect('\n'.isNotNullOrEmpty, true);
     });
 
+    test('.isNullOrBlank', () {
+      expect(null.isNullOrBlank, true);
+      expect(''.isNullOrBlank, true);
+      expect(' '.isNullOrBlank, true);
+      expect('\n'.isNullOrBlank, true);
+      expect(' foo '.isNullOrBlank, false);
+    });
+
+    test('.isNotNullOrBlank', () {
+      expect(null.isNotNullOrBlank, false);
+      expect(''.isNotNullOrBlank, false);
+      expect(' '.isNotNullOrBlank, false);
+      expect('\n'.isNotNullOrBlank, false);
+      expect(' foo '.isNotNullOrBlank, true);
+    });
+
     test('.toUtf8()', () {
       expect(''.toUtf8(), []);
       expect('hello'.toUtf8(), [104, 101, 108, 108, 111]);