Add support for instant column additions

src/Illuminate/Database/Schema/ColumnDefinition.php

@@ -15,6 +15,7 @@
  * @method $this default(mixed $value) Specify a "default" value for the column
  * @method $this first() Place the column "first" in the table (MySQL)
  * @method $this from(int $startingValue) Set the starting value of an auto-incrementing field (MySQL / PostgreSQL)
+ * @method $this instant() Specify that algorithm=instant should be used for the column operation (MySQL)
  * @method $this generatedAs(string|\Illuminate\Contracts\Database\Query\Expression $expression = null) Create a SQL compliant identity column (PostgreSQL)
  * @method $this index(bool|string $indexName = null) Add an index
  * @method $this invisible() Specify that the column should be invisible to "SELECT *" (MySQL)

src/Illuminate/Database/Schema/Grammars/MySqlGrammar.php

@@ -310,9 +310,10 @@ protected function compileCreateEngine($sql, Blueprint $blueprint)
      */
     public function compileAdd(Blueprint $blueprint, Fluent $command)
     {
-        return sprintf('alter table %s add %s',
+        return sprintf('alter table %s add %s%s',
             $this->wrapTable($blueprint),
-            $this->getColumn($blueprint, $command->column)
+            $this->getColumn($blueprint, $command->column),
+            $command->column->instant ? ', algorithm=instant' : ''
         );
     }
 
@@ -403,7 +404,13 @@ public function compileChange(Blueprint $blueprint, Fluent $command)
             $this->getType($column)
         );
 
-        return $this->addModifiers($sql, $blueprint, $column);
+        $sql = $this->addModifiers($sql, $blueprint, $column);
+
+        if ($column->instant) {
+            $sql .= ', algorithm=instant';
+        }
+
+        return $sql;
     }
 
     /**

tests/Database/DatabaseMySqlSchemaGrammarTest.php

@@ -1604,6 +1604,26 @@ protected function getConnection(
             ->getMock();
     }
 
+    public function testAddingColumnWithAlgorithm()
+    {
+        $blueprint = new Blueprint($this->getConnection(), 'users');
+        $blueprint->string('name')->instant();
+        $statements = $blueprint->toSql();
+
+        $this->assertCount(1, $statements);
+        $this->assertSame('alter table `users` add `name` varchar(255) not null, algorithm=instant', $statements[0]);
+    }
+
+    public function testChangingColumnWithAlgorithm()
+    {
+        $blueprint = new Blueprint($this->getConnection(), 'users');
+        $blueprint->string('name', 100)->change()->instant();
+        $statements = $blueprint->toSql();
+
+        $this->assertCount(1, $statements);
+        $this->assertSame('alter table `users` modify `name` varchar(100) not null, algorithm=instant', $statements[0]);
+    }
+
     public function getGrammar(?Connection $connection = null)
     {
         return new MySqlGrammar($connection ?? $this->getConnection());