Add NumericHelper::isInteger()

Co-authored-by: Alexander Makarov <sam@rmcreative.ru>

Author: vjik

CHANGELOG.md

@@ -4,6 +4,7 @@
 ## 1.1.1 under development
 
 - Enh #62: Add method `StringHelper::split` that split a string to array with non-empty lines (vjik)
+- Enh #63: Add method `NumericHelper::isInteger` that checks whether the given string is an integer number (vjik)
 
 ## 1.1.0 November 13, 2020
 
@@ -21,4 +22,3 @@
 - Initial release.
 
 
-

README.md

@@ -97,6 +97,7 @@ The following methods are available:
 
 - toOrdinal
 - normalize
+- isInteger
 
 ## Inflector usage
 

src/NumericHelper.php

@@ -61,4 +61,14 @@ public static function normalize($value): string
  $value = str_replace([' ', ','], ['', '.'], (string)$value);
  return preg_replace('/\.(?=.*\.)/', '', $value);
  }
+
+ /**
+ * Checks whether the given string is an integer number.
+ * @param mixed $value
+ * @return bool
+ */
+ public static function isInteger($value): bool
+ {
+ return filter_var($value, FILTER_VALIDATE_INT) !== false;
+ }
 }

tests/NumericHelperTest.php

@@ -66,4 +66,30 @@ public function testNormalizeNumberWithIncorrectType(): void
  $this->expectException(\InvalidArgumentException::class);
  NumericHelper::normalize([]);
  }
+
+ public function dataIsInteger(): array
+ {
+ return [
+ [new \stdClass(), false],
+ [[], false],
+ ['42', true],
+ ['-42', true],
+ ['0', true],
+ [' 7', true],
+ ['-', false],
+ ['hello', false],
+ ['', false],
+ ];
+ }
+
+ /**
+ * @dataProvider dataIsInteger
+ *
+ * @param mixed $value
+ * @param bool $expected
+ */
+ public function testIsInteger($value, bool $expected): void
+ {
+ $this->assertSame($expected, NumericHelper::isInteger($value));
+ }
 }