Restrict testDataValidationScalar() to the scalar validation key

CHANGELOG.md

@@ -6,8 +6,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased](https://github.com/orca-services/cakephp-data-validation-testing)
 
 ### Added
+- `testDataValidationContains()` to assert that specific validation errors are present, ignoring others on the same field.
 
 ### Changed
+- `testDataValidationScalar()` now checks only the `scalar` rule by default.
 
 ### Fixed
 

src/Traits/DataValidationTestTrait.php

@@ -328,6 +328,43 @@ protected function testDataValidation(
         static::assertEquals($expected, $errors);
     }
 
+    /**
+     * Validate that a field's data validation error array contains the expected "rule name" => "message" pair(s)
+     *
+     * Other validation errors will be ignored.
+     *
+     * @param Table $table The table to test.
+     * @param string $fieldName The field to check for data validation errors.
+     * @param array $dataSet The data set to test.
+     * @param array $expected The expected data validation errors ("rule name" => "message") that must be present.
+     * @param array $options Additional options for newEntity.
+     * @return void
+     * @see \Cake\Validation\Validator::validate()
+     */
+    protected function testDataValidationContains(
+        Table $table,
+        string $fieldName,
+        array $dataSet,
+        array $expected,
+        array $options = [],
+    ): void {
+        $entity = $table->newEntity($dataSet, $options);
+        $errors = $entity->getError($fieldName);
+
+        foreach ($expected as $rule => $message) {
+            static::assertArrayHasKey($rule, $errors, sprintf(
+                'Field `%s` does not have expected validation error `%s`.',
+                $fieldName,
+                $rule,
+            ));
+            static::assertSame($message, $errors[$rule], sprintf(
+                'Validation error message for field `%s` and rule `%s` does not match expected.',
+                $fieldName,
+                $rule,
+            ));
+        }
+    }
+
     /**
      * Validate that a given data set for a given table leads to the expected rule errors
      *
@@ -473,13 +510,10 @@ protected function testDataValidationScalar(
         ?array $expected = null,
         ?array $options = [],
     ): void {
-        $dataset = [$fieldName => []];
+        $dataset = [$fieldName => []]; // A non-scalar value
 
-        $expected ??= [
-            'scalar' => 'The provided value must be scalar',
-            'maxLength' => 'The provided value must be at most `50` characters long',
-        ];
-        $this->testDataValidation($table, $fieldName, $dataset, $expected, $options);
+        $expected ??= ['scalar' => 'The provided value must be scalar'];
+        $this->testDataValidationContains($table, $fieldName, $dataset, $expected, $options);
     }
 
     /**

tests/TestCase/Traits/DataValidationTestTraitTest.php

@@ -280,12 +280,9 @@ public function testTestDataValidationScalar(): void
     {
         // Ensure data validation of the field works as expected first
         $field = 'scalar_field';
-        $expectedErrors = [
-            'scalar' => 'The provided value must be scalar',
-            'maxLength' => 'The provided value must be at most `50` characters long',
-        ];
+        $expectedErrors = ['scalar' => 'The provided value must be scalar'];
         $dataSet = [$field => []];
-        $this->testDataValidation($this->table, $field, $dataSet, $expectedErrors);
+        $this->testDataValidationContains($this->table, $field, $dataSet, $expectedErrors);
 
         $this->testDataValidationScalar($this->table, $field);
     }