Fix up decimal migration_diff

Author: dereuromark

src/Command/BakeMigrationDiffCommand.php

@@ -308,6 +308,16 @@ protected function getColumns(): void
                         unset($changedAttributes['length']);
                     }
 
+                    // For decimal columns, ensure precision (scale) is included for proper conversion
+                    if (
+                        isset($column['type']) &&
+                        ($column['type'] === 'decimal' || $column['type'] === 'float') &&
+                        !isset($changedAttributes['precision']) &&
+                        isset($column['precision'])
+                    ) {
+                        $changedAttributes['precision'] = $column['precision'];
+                    }
+
                     $this->templateData[$table]['columns']['changed'][$columnName] = $changedAttributes;
                 }
             }

tests/TestCase/Command/BakeMigrationDiffCommandTest.php

@@ -240,6 +240,19 @@ public function testBakingDiffWithAutoIdIncompatibleUnsignedPrimaryKeys(): void
         $this->runDiffBakingTest('WithAutoIdIncompatibleUnsignedPrimaryKeys');
     }
 
+    /**
+     * Tests that baking a diff with decimal column changes includes precision
+     * This is a regression test for the fix that ensures precision is included for decimal/float columns
+     *
+     * @return void
+     */
+    public function testBakingDiffDecimalChange(): void
+    {
+        $this->skipIf(!env('DB_URL_COMPARE'));
+
+        $this->runDiffBakingTest('DecimalChange');
+    }
+
     /**
      * Tests that baking a diff with --plugin option only includes tables with Table classes
      */

tests/comparisons/Diff/decimalChange/schema-dump-test_comparisons_mysql.lock

@@ -0,0 +1,48 @@
+<?php
+declare(strict_types=1);
+
+use Migrations\BaseMigration;
+
+class TheDiffDecimalChangeMysql extends BaseMigration
+{
+    /**
+     * Up Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/migrations/4/en/migrations.html#the-up-method
+     *
+     * @return void
+     */
+    public function up(): void
+    {
+        $this->table('products')
+            ->changeColumn('price', 'decimal', [
+                'default' => null,
+                'limit' => null,
+                'null' => false,
+                'precision' => 10,
+                'scale' => 2,
+            ])
+            ->update();
+    }
+
+    /**
+     * Down Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/phinx/0/en/migrations.html#the-down-method
+     *
+     * @return void
+     */
+    public function down(): void
+    {
+        $this->table('products')
+            ->changeColumn('price', 'decimal', [
+                'default' => null,
+                'null' => false,
+                'precision' => 8,
+                'scale' => 2,
+            ])
+            ->update();
+    }
+}

tests/comparisons/Diff/decimalChange/schema-dump-test_comparisons_pgsql.lock

@@ -0,0 +1,48 @@
+<?php
+declare(strict_types=1);
+
+use Migrations\BaseMigration;
+
+class TheDiffDecimalChangePgsql extends BaseMigration
+{
+    /**
+     * Up Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/migrations/4/en/migrations.html#the-up-method
+     *
+     * @return void
+     */
+    public function up(): void
+    {
+        $this->table('products')
+            ->changeColumn('price', 'decimal', [
+                'default' => null,
+                'limit' => null,
+                'null' => false,
+                'precision' => 10,
+                'scale' => 2,
+            ])
+            ->update();
+    }
+
+    /**
+     * Down Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/phinx/0/en/migrations.html#the-down-method
+     *
+     * @return void
+     */
+    public function down(): void
+    {
+        $this->table('products')
+            ->changeColumn('price', 'decimal', [
+                'default' => null,
+                'null' => false,
+                'precision' => 8,
+                'scale' => 2,
+            ])
+            ->update();
+    }
+}

tests/comparisons/Diff/decimalChange/the_diff_decimal_change_mysql.php

@@ -8,6 +8,7 @@
 use Cake\Console\ConsoleOptionParser;
 use Cake\Core\Plugin;
 use Migrations\Command\BakeMigrationDiffCommand;
+use RuntimeException;
 use function Cake\Core\env;
 
 class CustomBakeMigrationDiffCommand extends BakeMigrationDiffCommand
@@ -63,6 +64,11 @@ protected function getDumpSchema(Arguments $args): array
         $diffConfigFolder = Plugin::path('Migrations') . 'tests' . DS . 'comparisons' . DS . 'Diff' . DS . $comparison . DS;
         $diffDumpPath = $diffConfigFolder . 'schema-dump-test_comparisons_' . env('DB') . '.lock';
 
-        return unserialize(trim(file_get_contents($diffDumpPath)));
+        $contents = file_get_contents($diffDumpPath);
+        if ($contents === false) {
+            throw new RuntimeException("Unable to read dump file: {$diffDumpPath}");
+        }
+
+        return unserialize(trim($contents));
     }
 }