Preserve all digits when casting a float to string and NaN, INF, and -INF are case insensitive.

Author: prwater

src/Cast.php

@@ -98,7 +98,7 @@ public static function isManFloatInclusive(mixed $value): bool
                                FILTER_SANITIZE_NUMBER_FLOAT,
                                FILTER_FLAG_ALLOW_FRACTION | FILTER_FLAG_ALLOW_SCIENTIFIC);
 
-        return ($filtered===$value || in_array($value, ['NAN', 'INF', '-INF'], true));
+        return ($filtered===$value || in_array(strtoupper($value), ['NAN', 'INF', '-INF'], true));
 
       default:
         return false;
@@ -312,19 +312,24 @@ public static function toManFloatInclusive(mixed $value, ?float $default = null)
       throw new InvalidCastException('Value can not be converted to float');
     }
 
-    if ($value==='NAN')
+    if (is_string($value))
     {
-      return NAN;
-    }
+      $upper = strtoupper($value);
 
-    if ($value==='INF')
-    {
-      return INF;
-    }
+      if ($upper==='NAN')
+      {
+        return NAN;
+      }
 
-    if ($value==='-INF')
-    {
-      return -INF;
+      if ($upper==='INF')
+      {
+        return INF;
+      }
+
+      if ($upper==='-INF')
+      {
+        return -INF;
+      }
     }
 
     return (float)$value;
@@ -386,6 +391,28 @@ public static function toManString(mixed $value, ?string $default = null): strin
       return '0';
     }
 
+    if (is_float($value))
+    {
+      if (is_nan($value))
+      {
+        return 'NaN';
+      }
+
+      if ($value===INF)
+      {
+        return 'INF';
+      }
+
+      if ($value===-INF)
+      {
+        return '-INF';
+      }
+
+      $string = sprintf('%.'.PHP_FLOAT_DIG.'E', $value);
+
+      return preg_replace('/(\.0+E)|(0+E)/', 'E', $string);
+    }
+
     return (string)$value;
   }
 

test/CastFloatInclusiveTest.php

@@ -224,7 +224,13 @@ public function validManFloatCases(): array
              'expected' => INF],
             ['value'    => '-INF',
              'expected' => -INF],
-            ['value'    => 'NAN',
+            ['value'    => 'NaN',
+             'expected' => NAN],
+            ['value'    => 'inf',
+             'expected' => INF],
+            ['value'    => '-inf',
+             'expected' => -INF],
+            ['value'    => 'nan',
              'expected' => NAN]];
   }
 

test/CastFloatTest.php

@@ -49,7 +49,10 @@ public function invalidOptFiniteFloatCases(): array
             [NAN],
             ['INF'],
             ['-INF'],
-            ['NAN']];
+            ['NaN'],
+            ['inf'],
+            ['-inf'],
+            ['nan']];
   }
 
   //--------------------------------------------------------------------------------------------------------------------

test/CastStringTest.php

@@ -92,6 +92,22 @@ public function testManStringWithValidValues(mixed $value, string $expected): vo
     self::assertSame($expected, $casted);
   }
 
+  //--------------------------------------------------------------------------------------------------------------------
+  /**
+   * Test the number of digits of a float cast tot a string.
+   */
+  public function testOptStringDigits(): void
+  {
+    $pi = Cast::toOptString(M_PI);
+    self::assertEquals(PHP_FLOAT_DIG + 5, strlen($pi));
+
+    $value = Cast::toOptString(100.0);
+    self::assertEquals('1E+2', $value);
+
+    $value = Cast::toOptString(0.01);
+    self::assertEquals('1E-2', $value);
+  }
+
   //--------------------------------------------------------------------------------------------------------------------
   /**
    * Test with default value.
@@ -174,13 +190,13 @@ public function validManStringCases(): array
 
     // Float test cases.
     $cases[] = ['value'    => 123.0,
-                'expected' => '123'];
+                'expected' => '1.23E+2'];
     $cases[] = ['value'    => INF,
                 'expected' => 'INF'];
     $cases[] = ['value'    => -INF,
                 'expected' => '-INF'];
     $cases[] = ['value'    => NAN,
-                'expected' => 'NAN'];
+                'expected' => 'NaN'];
 
     // Boolean test cases.
     $cases[] = ['value'    => false,