Add escape mechanism for double braces in templates and update related docs/tests

Author: antonmedv

docs/api.md

@@ -264,6 +264,11 @@ run('echo {{ message | quote }}');
 run('grep -r {{ pattern | quote }} {{release_path}}');
 ```
 
+To output literal `{{` without replacement, escape with a backslash `\{{`:
+```php
+run('echo \{{not_replaced}}'); // outputs: {{not_replaced}}
+```
+
 
 
 | Argument | Type | Comment |
@@ -459,7 +464,7 @@ Writes a message to the output and adds a newline at the end.
 parse(string $value): string
 ```
 
-Parse set values.
+Parse set values. Use `\{{` to escape brackets and prevent replacement.
 
 
 ## set()

docs/basics.md

@@ -145,6 +145,12 @@ task('my_task', function () {
 });
 ```
 
+To output literal `{{` without replacement, escape with a backslash `\{{`:
+
+```php
+run('echo \{{not_replaced}}'); // outputs: {{not_replaced}}
+```
+
 ---
 
 ## Global Configurations

src/Configuration.php

@@ -115,7 +115,8 @@ public function parse(mixed $value): mixed
     {
         if (is_string($value)) {
             $normalizedValue = normalize_line_endings($value);
-            return preg_replace_callback('/\{\{\s*([\w\.\/-]+)\s*(?:\|\s*(\w+)\s*)?\}\}/', function (array $matches) {
+            $normalizedValue = str_replace('\{{', "\x00\x00", $normalizedValue);
+            $result = preg_replace_callback('/\{\{\s*([\w\.\/-]+)\s*(?:\|\s*(\w+)\s*)?\}\}/', function (array $matches) {
                 $value = $this->get($matches[1]);
                 if (isset($matches[2])) {
                     $value = match ($matches[2]) {
@@ -125,6 +126,7 @@ public function parse(mixed $value): mixed
                 }
                 return $value;
             }, $normalizedValue);
+            return str_replace("\x00\x00", '{{', $result);
         }
 
         return $value;

tests/src/Configuration/ConfigurationTest.php

@@ -159,6 +159,16 @@ public function testAddToParentCallback()
         self::assertEquals(['a', 'b', 'c'], $alpha->get('files'));
     }
 
+    public function testParseEscapedBraces()
+    {
+        $config = new Configuration();
+        $config->set('foo', 'a');
+
+        self::assertEquals('{{foo}}', $config->parse('\{{foo}}'));
+        self::assertEquals('a {{bar}}', $config->parse('{{foo}} \{{bar}}'));
+        self::assertEquals('{{foo}} {{bar}}', $config->parse('\{{foo}} \{{bar}}'));
+    }
+
     public function testParseQuoteFilter()
     {
         $config = new Configuration();