feat(rome_js_parser): EcmaScript @decorators #4252

crates/rome_js_formatter/src/comments.rs

@@ -166,6 +166,7 @@ impl CommentStyle for JsCommentStyle {
                 .or_else(handle_try_comment)
                 .or_else(handle_class_comment)
                 .or_else(handle_method_comment)
+                .or_else(handle_property_comments)
                 .or_else(handle_for_comment)
                 .or_else(handle_root_comments)
                 .or_else(handle_array_hole_comment)
@@ -184,6 +185,7 @@ impl CommentStyle for JsCommentStyle {
                 .or_else(handle_try_comment)
                 .or_else(handle_class_comment)
                 .or_else(handle_method_comment)
+                .or_else(handle_property_comments)
                 .or_else(handle_for_comment)
                 .or_else(handle_root_comments)
                 .or_else(handle_parameter_comment)
@@ -508,6 +510,28 @@ fn handle_method_comment(comment: DecoratedComment<JsLanguage>) -> CommentPlacem
     CommentPlacement::Default(comment)
 }
 
+fn handle_property_comments(comment: DecoratedComment<JsLanguage>) -> CommentPlacement<JsLanguage> {
+    let enclosing = comment.enclosing_node();
+
+    let is_property = matches!(
+        enclosing.kind(),
+        JsSyntaxKind::JS_PROPERTY_OBJECT_MEMBER | JsSyntaxKind::JS_PROPERTY_CLASS_MEMBER
+    );
+
+    if !is_property {
+        return CommentPlacement::Default(comment);
+    }
+
+    if let (Some(preceding), Some(following)) = (comment.preceding_node(), comment.following_node())
+    {
+        if preceding.kind() == JsSyntaxKind::JS_DECORATOR {
+            return CommentPlacement::leading(following.clone(), comment);
+        }
+    }
+
+    CommentPlacement::Default(comment)
+}
+
 /// Handle a all comments document.
 /// See `blank.js`
 fn handle_root_comments(comment: DecoratedComment<JsLanguage>) -> CommentPlacement<JsLanguage> {

crates/rome_js_formatter/src/generated.rs

@@ -4700,6 +4700,40 @@ impl IntoFormat<JsFormatContext> for rome_js_syntax::JsInitializerClause {
         )
     }
 }
+impl FormatRule<rome_js_syntax::JsDecorator>
+    for crate::js::auxiliary::decorator::FormatJsDecorator
+{
+    type Context = JsFormatContext;
+    #[inline(always)]
+    fn fmt(&self, node: &rome_js_syntax::JsDecorator, f: &mut JsFormatter) -> FormatResult<()> {
+        FormatNodeRule::<rome_js_syntax::JsDecorator>::fmt(self, node, f)
+    }
+}
+impl AsFormat<JsFormatContext> for rome_js_syntax::JsDecorator {
+    type Format<'a> = FormatRefWithRule<
+        'a,
+        rome_js_syntax::JsDecorator,
+        crate::js::auxiliary::decorator::FormatJsDecorator,
+    >;
+    fn format(&self) -> Self::Format<'_> {
+        FormatRefWithRule::new(
+            self,
+            crate::js::auxiliary::decorator::FormatJsDecorator::default(),
+        )
+    }
+}
+impl IntoFormat<JsFormatContext> for rome_js_syntax::JsDecorator {
+    type Format = FormatOwnedWithRule<
+        rome_js_syntax::JsDecorator,
+        crate::js::auxiliary::decorator::FormatJsDecorator,
+    >;
+    fn into_format(self) -> Self::Format {
+        FormatOwnedWithRule::new(
+            self,
+            crate::js::auxiliary::decorator::FormatJsDecorator::default(),
+        )
+    }
+}
 impl FormatRule<rome_js_syntax::TsOptionalPropertyAnnotation>
     for crate::ts::auxiliary::optional_property_annotation::FormatTsOptionalPropertyAnnotation
 {
@@ -6807,40 +6841,6 @@ impl IntoFormat<JsFormatContext> for rome_js_syntax::TsThisParameter {
         )
     }
 }
-impl FormatRule<rome_js_syntax::JsDecorator>
-    for crate::js::auxiliary::decorator::FormatJsDecorator
-{
-    type Context = JsFormatContext;
-    #[inline(always)]
-    fn fmt(&self, node: &rome_js_syntax::JsDecorator, f: &mut JsFormatter) -> FormatResult<()> {
-        FormatNodeRule::<rome_js_syntax::JsDecorator>::fmt(self, node, f)
-    }
-}
-impl AsFormat<JsFormatContext> for rome_js_syntax::JsDecorator {
-    type Format<'a> = FormatRefWithRule<
-        'a,
-        rome_js_syntax::JsDecorator,
-        crate::js::auxiliary::decorator::FormatJsDecorator,
-    >;
-    fn format(&self) -> Self::Format<'_> {
-        FormatRefWithRule::new(
-            self,
-            crate::js::auxiliary::decorator::FormatJsDecorator::default(),
-        )
-    }
-}
-impl IntoFormat<JsFormatContext> for rome_js_syntax::JsDecorator {
-    type Format = FormatOwnedWithRule<
-        rome_js_syntax::JsDecorator,
-        crate::js::auxiliary::decorator::FormatJsDecorator,
-    >;
-    fn into_format(self) -> Self::Format {
-        FormatOwnedWithRule::new(
-            self,
-            crate::js::auxiliary::decorator::FormatJsDecorator::default(),
-        )
-    }
-}
 impl FormatRule<rome_js_syntax::TsAnyType> for crate::ts::types::any_type::FormatTsAnyType {
     type Context = JsFormatContext;
     #[inline(always)]

crates/rome_js_formatter/src/js/any/method_modifier.rs

@@ -10,6 +10,7 @@ impl FormatRule<AnyJsMethodModifier> for FormatAnyJsMethodModifier {
         match node {
             AnyJsMethodModifier::TsAccessibilityModifier(node) => node.format().fmt(f),
             AnyJsMethodModifier::JsStaticModifier(node) => node.format().fmt(f),
+            AnyJsMethodModifier::JsDecorator(node) => node.format().fmt(f),
             AnyJsMethodModifier::TsOverrideModifier(node) => node.format().fmt(f),
         }
     }

crates/rome_js_formatter/src/js/any/property_modifier.rs

@@ -11,6 +11,7 @@ impl FormatRule<AnyJsPropertyModifier> for FormatAnyJsPropertyModifier {
             AnyJsPropertyModifier::TsAccessibilityModifier(node) => node.format().fmt(f),
             AnyJsPropertyModifier::JsStaticModifier(node) => node.format().fmt(f),
             AnyJsPropertyModifier::JsAccessorModifier(node) => node.format().fmt(f),
+            AnyJsPropertyModifier::JsDecorator(node) => node.format().fmt(f),
             AnyJsPropertyModifier::TsReadonlyModifier(node) => node.format().fmt(f),
             AnyJsPropertyModifier::TsOverrideModifier(node) => node.format().fmt(f),
         }

crates/rome_js_formatter/src/ts/any/method_signature_modifier.rs

@@ -9,6 +9,7 @@ impl FormatRule<AnyTsMethodSignatureModifier> for FormatAnyTsMethodSignatureModi
     fn fmt(&self, node: &AnyTsMethodSignatureModifier, f: &mut JsFormatter) -> FormatResult<()> {
         match node {
             AnyTsMethodSignatureModifier::TsAccessibilityModifier(node) => node.format().fmt(f),
+            AnyTsMethodSignatureModifier::JsDecorator(node) => node.format().fmt(f),
             AnyTsMethodSignatureModifier::JsStaticModifier(node) => node.format().fmt(f),
             AnyTsMethodSignatureModifier::TsOverrideModifier(node) => node.format().fmt(f),
             AnyTsMethodSignatureModifier::TsAbstractModifier(node) => node.format().fmt(f),

crates/rome_js_formatter/src/ts/any/property_signature_modifier.rs

@@ -11,6 +11,7 @@ impl FormatRule<AnyTsPropertySignatureModifier> for FormatAnyTsPropertySignature
             AnyTsPropertySignatureModifier::TsDeclareModifier(node) => node.format().fmt(f),
             AnyTsPropertySignatureModifier::TsAccessibilityModifier(node) => node.format().fmt(f),
             AnyTsPropertySignatureModifier::JsStaticModifier(node) => node.format().fmt(f),
+            AnyTsPropertySignatureModifier::JsDecorator(node) => node.format().fmt(f),
             AnyTsPropertySignatureModifier::JsAccessorModifier(node) => node.format().fmt(f),
             AnyTsPropertySignatureModifier::TsReadonlyModifier(node) => node.format().fmt(f),
             AnyTsPropertySignatureModifier::TsOverrideModifier(node) => node.format().fmt(f),

crates/rome_js_formatter/tests/quick_test.rs

@@ -13,13 +13,11 @@ mod language {
 // use this test check if your snippet prints as you wish, without using a snapshot
 fn quick_test() {
     let src = r#"
-const bar =
-  (
-    @deco
-    class {
-      //
-    }
-  );
+class Test2 {
+	@anotherDecorator() // leading comment
+	prop: string;
+}
+
 
 "#;
     let syntax = SourceType::tsx();

crates/rome_js_formatter/tests/specs/prettier/js/babel-plugins/decorators.js.snap

@@ -0,0 +1,92 @@
+---
+source: crates/rome_formatter_test/src/snapshot_builder.rs
+info: js/babel-plugins/decorators.js
+---
+
+# Input
+
+```js
+// https://babeljs.io/docs/en/babel-plugin-proposal-decorators
+
+@annotation
+class MyClass { }
+
+function annotation(target) {
+   target.annotated = true;
+}
+
+@isTestable(true)
+class MyClass { }
+
+function isTestable(value) {
+   return function decorator(target) {
+      target.isTestable = value;
+   }
+}
+
+class C {
+  @enumerable(false)
+  method() { }
+}
+
+function enumerable(value) {
+  return function (target, key, descriptor) {
+     descriptor.enumerable = value;
+     return descriptor;
+  }
+}
+
+```
+
+
+# Prettier differences
+
+```diff
+--- Prettier
++++ Rome
+@@ -17,8 +17,7 @@
+ }
+
+ class C {
+-  @enumerable(false)
+-  method() {}
++  @enumerable(false) method() {}
+ }
+
+ function enumerable(value) {
+```
+
+# Output
+
+```js
+// https://babeljs.io/docs/en/babel-plugin-proposal-decorators
+
+@annotation
+class MyClass {}
+
+function annotation(target) {
+  target.annotated = true;
+}
+
+@isTestable(true)
+class MyClass {}
+
+function isTestable(value) {
+  return function decorator(target) {
+    target.isTestable = value;
+  };
+}
+
+class C {
+  @enumerable(false) method() {}
+}
+
+function enumerable(value) {
+  return function (target, key, descriptor) {
+    descriptor.enumerable = value;
+    return descriptor;
+  };
+}
+```
+
+

crates/rome_js_formatter/tests/specs/prettier/js/decorator-auto-accessors/comments.js.snap

@@ -0,0 +1,41 @@
+---
+source: crates/rome_formatter_test/src/snapshot_builder.rs
+info: js/decorator-auto-accessors/comments.js
+---
+
+# Input
+
+```js
+class A {
+  @dec()
+  // comment
+  accessor b;
+}
+
+```
+
+
+# Prettier differences
+
+```diff
+--- Prettier
++++ Rome
+@@ -1,5 +1,4 @@
+ class A {
+-  @dec()
+-  // comment
++  @dec() // comment
+   accessor b;
+ }
+```
+
+# Output
+
+```js
+class A {
+  @dec() // comment
+  accessor b;
+}
+```
+
+

crates/rome_js_formatter/tests/specs/prettier/js/decorator-comments/comments.js.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/rome_formatter_test/src/snapshot_builder.rs
-assertion_line: 212
 info: js/decorator-comments/comments.js
 ---