feat: add support for .jsonc files

crates/rome_cli/src/configuration.rs

@@ -72,7 +72,7 @@ impl LoadedConfiguration {
 					)
 
 				})?;
-            let deserialized = deserialize_from_json_str::<Configuration>(content.as_str());
+            let deserialized = deserialize_from_json_str::<Configuration>(content.as_str(), true);
             deserialized_configurations.push(deserialized)
         }
         Ok(deserialized_configurations)

crates/rome_cli/tests/commands/format.rs

@@ -1866,7 +1866,7 @@ fn ignore_comments_error_when_allow_comments() {
         Args::from([("format"), file_path.as_os_str().to_str().unwrap()].as_slice()),
     );
 
-    // assert!(result.is_ok(), "run_cli returned {result:?}");
+    assert!(result.is_ok(), "run_cli returned {result:?}");
 
     assert_cli_snapshot(SnapshotPayload::new(
         module_path!(),
@@ -1876,3 +1876,78 @@ fn ignore_comments_error_when_allow_comments() {
         result,
     ));
 }
+
+#[test]
+fn format_jsonc_files() {
+    let mut fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    let code = r#"
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+	"#;
+    let file_path = Path::new("file.jsonc");
+    fs.insert(file_path.into(), code.as_bytes());
+
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from([("format"), file_path.as_os_str().to_str().unwrap()].as_slice()),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "format_jsonc_files",
+        fs,
+        console,
+        result,
+    ));
+}
+
+#[test]
+fn treat_known_json_files_as_jsonc_files() {
+    let mut fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    let code = r#"
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+	"#;
+    let ts = Path::new("files/typescript.json");
+    fs.insert(ts.into(), code.as_bytes());
+    let eslint = Path::new("files/.eslintrc.json");
+    fs.insert(eslint.into(), code.as_bytes());
+    let jshint = Path::new("files/.jshintrc");
+    fs.insert(jshint.into(), code.as_bytes());
+    let babel = Path::new("files/.babelrc");
+    fs.insert(babel.into(), code.as_bytes());
+
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from(
+            [
+                ("format"),
+                ts.as_os_str().to_str().unwrap(),
+                eslint.as_os_str().to_str().unwrap(),
+                jshint.as_os_str().to_str().unwrap(),
+                babel.as_os_str().to_str().unwrap(),
+            ]
+            .as_slice(),
+        ),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "treat_known_json_files_as_jsonc_files",
+        fs,
+        console,
+        result,
+    ));
+}

crates/rome_cli/tests/snapshots/main_commands_format/format_jsonc_files.snap

@@ -0,0 +1,37 @@
+---
+source: crates/rome_cli/tests/snap_test.rs
+expression: content
+---
+## `file.jsonc`
+
+```jsonc
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+
+```
+
+# Emitted Messages
+
+```block
+file.jsonc format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+Compared 1 file(s) in <TIME>
+```
+
+

crates/rome_cli/tests/snapshots/main_commands_format/treat_known_json_files_as_jsonc_files.snap

@@ -0,0 +1,115 @@
+---
+source: crates/rome_cli/tests/snap_test.rs
+expression: content
+---
+## `files/.babelrc`
+
+```babelrc
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+	
+```
+
+## `files/.eslintrc.json`
+
+```json
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+
+```
+
+## `files/.jshintrc`
+
+```jshintrc
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+	
+```
+
+## `files/typescript.json`
+
+```json
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+
+```
+
+# Emitted Messages
+
+```block
+files/typescript.json format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+files/.eslintrc.json format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+files/.jshintrc format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+files/.babelrc format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+Compared 4 file(s) in <TIME>
+```
+
+

crates/rome_cli/tests/snapshots/main_commands_format/treats_typescript_json_like_jsonc.snap

@@ -0,0 +1,37 @@
+---
+source: crates/rome_cli/tests/snap_test.rs
+expression: content
+---
+## `typescript.json`
+
+```json
+
+/*test*/ [
+
+/* some other comment*/1, 2, 3]
+
+```
+
+# Emitted Messages
+
+```block
+typescript.json format ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+
+  i Formatter would have printed the following content:
+  
+    1   │ - 
+    2   │ - /*test*/·[
+    3   │ - 
+    4   │ - /*·some·other·comment*/1,·2,·3]
+    5   │ - → 
+      1 │ + /*test*/·[/*·some·other·comment*/·1,·2,·3]
+      2 │ + 
+  
+
+```
+
+```block
+Compared 1 file(s) in <TIME>
+```
+
+

crates/rome_deserialize/src/json.rs

@@ -588,22 +588,27 @@ pub fn with_only_known_variants(
 /// }
 ///
 /// # fn main() -> Result<(), DeserializationDiagnostic> {
-/// let source = r#"{ "lorem": true }"#;
-///  let deserialized = deserialize_from_json_str::<NewConfiguration>(&source);
+///  let source = r#"{ "lorem": true }"#;
+///  let deserialized = deserialize_from_json_str::<NewConfiguration>(&source, false);
 ///  assert!(!deserialized.has_errors());
 ///  assert_eq!(deserialized.into_deserialized(), NewConfiguration { lorem: true });
 /// # Ok(())
 /// # }
 ///
 ///
 /// ```
-pub fn deserialize_from_json_str<Output>(source: &str) -> Deserialized<Output>
+pub fn deserialize_from_json_str<Output>(source: &str, allow_comments: bool) -> Deserialized<Output>
 where
     Output: Default + VisitJsonNode + JsonDeserialize,
 {
     let mut output = Output::default();
     let mut diagnostics = vec![];
-    let parse = parse_json(source, JsonParserOptions::default());
+    let options = if allow_comments {
+        JsonParserOptions::default().with_allow_comments()
+    } else {
+        JsonParserOptions::default()
+    };
+    let parse = parse_json(source, options);
     Output::deserialize_from_ast(&parse.tree(), &mut output, &mut diagnostics);
     let mut errors = parse
         .into_diagnostics()

crates/rome_json_syntax/src/file_source.rs

@@ -28,6 +28,10 @@ impl JsonFileSource {
             variant: JsonVariant::Jsonc,
         }
     }
+
+    pub const fn is_jsonc(&self) -> bool {
+        matches!(self.variant, JsonVariant::Jsonc)
+    }
 }
 
 impl<'a> FileSource<'a, JsonLanguage> for JsonFileSource {}

crates/rome_service/src/configuration/diagnostics.rs

@@ -340,7 +340,7 @@ mod test {
     #[test]
     fn deserialization_error() {
         let content = "{ \n\n\"formatter\" }";
-        let result = deserialize_from_json_str::<Configuration>(content);
+        let result = deserialize_from_json_str::<Configuration>(content, false);
 
         assert!(result.has_errors());
         for diagnostic in result.into_diagnostics() {
@@ -363,6 +363,7 @@ mod test {
     }
   }
 }"#;
-        let _result = deserialize_from_json_str::<Configuration>(content).into_deserialized();
+        let _result =
+            deserialize_from_json_str::<Configuration>(content, false).into_deserialized();
     }
 }

crates/rome_service/src/configuration/mod.rs

@@ -348,7 +348,7 @@ pub fn load_config(
             directory_path,
             file_path,
         } = auto_search_result;
-        let deserialized = deserialize_from_json_str::<Configuration>(&content);
+        let deserialized = deserialize_from_json_str::<Configuration>(&content, true);
         Ok(Some(ConfigurationPayload {
             deserialized,
             configuration_file_path: file_path,