feat: add support for test expression instance of

Close GH-45

Ref: https://craftcms.com/docs/5.x/reference/twig/tests.html#instance-of

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Features
 - Add support for default value on macros
+- Add support for test expression `instance of`, feature of [Craft CMS](https://craftcms.com/docs/5.x/reference/twig/tests.html#instance-of)
 
 ---
 ## 0.9.1 (2024-10-10)

src/melody/melody-extension-core/operators.js

@@ -330,6 +330,11 @@ export const TestIterableExpression = createTest(
     "iterable",
     "TestIterableExpression"
 );
+
+export const TestInstanceOfExpression = createTest(
+    "instance of",
+    "TestInstanceOfExpression"
+);
 //endregion
 
 //region Utilities

src/print/TestExpression.js

@@ -1,5 +1,5 @@
 import { doc } from "prettier";
-import { findParentNode } from "../util/index.js";
+import { findParentNode, STRING_NEEDS_QUOTES } from "../util/index.js";
 
 const { softline, line, group, join, indent } = doc.builders;
 
@@ -11,13 +11,15 @@ const textMap = {
     TestEvenExpression: "even",
     TestOddExpression: "odd",
     TestIterableExpression: "iterable",
-    TestSameAsExpression: "same as"
+    TestSameAsExpression: "same as",
+    TestInstanceOfExpression: "instance of"
 };
 
 const isNegator = node =>
     node.constructor.name === "UnarySubclass" && node.operator === "not";
 
 const p = (node, path, print) => {
+    node[STRING_NEEDS_QUOTES] = true;
     const expressionType = node.__proto__.type;
     const parts = [path.call(print, "expression"), " is "];
     const parent = findParentNode(path);

tests/Expressions/__snapshots__/operators.snap.twig

@@ -55,6 +55,18 @@
     pomegrenade
 ) }}
 
+{# Craft CMS specific feature #}
+{# Ref: https://craftcms.com/docs/5.x/reference/twig/tests.html#instance-of #}
+{% if
+    element is instance of('craft\\elements\\Entry')
+        or element is instance of(
+            constant('Namespace\\Classname::CONSTANT_NAME')
+        ) %}
+    <h1>
+        {{ entry.title }}
+    </h1>
+{% endif %}
+
 {{ dump(test) }}
 {{ range(2, 3)|sort|join(',') }}
 {{ range(3)|sort|join(',') }}

tests/Expressions/operators.twig

@@ -46,6 +46,12 @@
 {{ a is not same as(b) }}
 {{ a is not same as(banana, apple, orange, lemonade, kiwi, coconut, pineapple, pomegrenade) }}
 
+{# Craft CMS specific feature #}
+{# Ref: https://craftcms.com/docs/5.x/reference/twig/tests.html#instance-of #}
+{% if element is instance of('craft\\elements\\Entry') or element is instance of(constant('Namespace\\Classname::CONSTANT_NAME')) %}
+    <h1>{{ entry.title }}</h1>
+{% endif %}
+
 {{ dump(test) }}
 {{ range(2, 3) | sort | join(',') }}
 {{ range(3) | sort | join(',') }}