improve unicode support on Str::squish() (#41877)

Author: rodrigopedra

src/Illuminate/Support/Str.php

@@ -889,7 +889,7 @@ public static function snake($value, $delimiter = '_')
      */
     public static function squish($value)
     {
-        return preg_replace('/\s+/', ' ', trim($value));
+        return preg_replace('~\s+~u', ' ', preg_replace('~^\s+|\s+$~u', '', $value));
     }
 
     /**

tests/Support/SupportStrTest.php

@@ -547,6 +547,12 @@ public function testSquish()
             php
             framework
         '));
+        $this->assertSame('laravel php framework', Str::squish('   laravel   php   framework   '));
+        $this->assertSame('123', Str::squish('   123    '));
+        $this->assertSame('だ', Str::squish('だ'));
+        $this->assertSame('ム', Str::squish('ム'));
+        $this->assertSame('だ', Str::squish('   だ    '));
+        $this->assertSame('ム', Str::squish('   ム    '));
     }
 
     public function testStudly()

tests/Support/SupportStringableTest.php

@@ -620,6 +620,12 @@ public function testSquish()
             with
             spaces
         ')->squish());
+        $this->assertSame('laravel php framework', (string) $this->stringable('   laravel   php   framework   ')->squish());
+        $this->assertSame('123', (string) $this->stringable('   123    ')->squish());
+        $this->assertSame('だ', (string) $this->stringable('だ')->squish());
+        $this->assertSame('ム', (string) $this->stringable('ム')->squish());
+        $this->assertSame('だ', (string) $this->stringable('   だ    ')->squish());
+        $this->assertSame('ム', (string) $this->stringable('   ム    ')->squish());
     }
 
     public function testStart()