Swap empty with explicit string comparison.

Author: michael-rubel

src/Artisan/stubs/value-object.stub

@@ -67,7 +67,7 @@ class {{ class }} extends ValueObject
     {
         // TODO: Implement validate() method.
 
-        if (empty($this->value())) {
+        if ($this->value() === '') {
             throw ValidationException::withMessages(['Value of {{ class }} cannot be empty.']);
         }
     }

src/Collection/Complex/ClassString.php

@@ -114,7 +114,7 @@ public function value(): string
      */
     protected function validate(): void
     {
-        if (empty($this->value())) {
+        if ($this->value() === '') {
             throw ValidationException::withMessages(['Class string cannot be empty.']);
         }
     }

src/Collection/Complex/FullName.php

@@ -102,7 +102,7 @@ public function toArray(): array
      */
     protected function validate(): void
     {
-        if (empty($this->value())) {
+        if ($this->value() === '') {
             throw ValidationException::withMessages(['Full name cannot be empty.']);
         }
 

src/Collection/Complex/TaxNumber.php

@@ -141,7 +141,7 @@ public function toArray(): array
      */
     protected function validate(): void
     {
-        if (empty($this->value())) {
+        if ($this->value() === '') {
             throw ValidationException::withMessages(['Tax number cannot be empty.']);
         }
     }

src/Collection/Primitive/Text.php

@@ -74,7 +74,7 @@ public function value(): string
      */
     protected function validate(): void
     {
-        if (empty($this->value())) {
+        if ($this->value() === '') {
             throw new InvalidArgumentException('Text cannot be empty.');
         }
     }