fix: loose strategy when suffer trailing comma in json

crates/rome_json_parser/src/syntax.rs

@@ -1,7 +1,8 @@
 use crate::prelude::*;
+use rome_diagnostics::DiagnosticExt;
 use rome_json_syntax::JsonSyntaxKind;
 use rome_json_syntax::JsonSyntaxKind::*;
-use rome_parser::diagnostic::{expected_any, expected_node};
+use rome_parser::diagnostic::{expected_any, expected_node, expected_token};
 use rome_parser::parse_recovery::ParseRecovery;
 use rome_parser::parsed_syntax::ParsedSyntax::Absent;
 use rome_parser::prelude::ParsedSyntax::Present;
@@ -171,10 +172,19 @@ fn parse_sequence(p: &mut JsonParser, root_kind: SequenceKind) -> ParsedSyntax {
         let mut progress = ParserProgress::default();
 
         while !p.at(EOF) && !p.at(current.kind.close_paren()) {
-            if first {
+            let last_token = if first {
                 first = false;
+				Some(current.kind.open_paren())
             } else {
-                p.expect(T![,]);
+                let last_token = p.last();
+				p.expect(T![,]);
+				last_token
+            };
+
+            if p.at(current.kind.close_paren()) && !matches!(last_token, Some(T![,]) | None) {
+				// SAFETY: we know that previous should not be none
+				// let builder = p.err_builder("Trailing comma is not allowed in json", p.cur_range()).with_severity(rome_diagnostics::Severity::Warning);
+                break;
             }
 
             progress.assert_progressing(p);
@@ -214,6 +224,9 @@ fn parse_sequence(p: &mut JsonParser, root_kind: SequenceKind) -> ParsedSyntax {
             }
         }
 
+        // while p.at(T![,]) {
+        //     p.bump_any();
+        // }
         current.list.complete(p, current.kind.list_kind());
         p.expect(current.kind.close_paren());
         let node = current.node.complete(p, current.kind.node_kind());

crates/rome_json_parser/tests/json_test_suite/ok/array_number_and_comma.json

@@ -0,0 +1 @@
+[1,]

crates/rome_json_parser/tests/json_test_suite/err/array_number_and_comma.json.snap → crates/rome_json_parser/tests/json_test_suite/ok/array_number_and_comma.json.snap

@@ -7,6 +7,7 @@ expression: snapshot
 
 ```json
 [1,]
+
 ```
 
 
@@ -25,14 +26,14 @@ JsonRoot {
         ],
         r_brack_token: R_BRACK@3..4 "]" [] [],
     },
-    eof_token: EOF@4..4 "" [] [],
+    eof_token: EOF@4..5 "" [Newline("\n")] [],
 }
 ```
 
 ## CST
 
 ```
-0: JSON_ROOT@0..4
+0: JSON_ROOT@0..5
   0: JSON_ARRAY_VALUE@0..4
     0: L_BRACK@0..1 "[" [] []
     1: JSON_ARRAY_ELEMENT_LIST@1..3
@@ -41,25 +42,8 @@ JsonRoot {
       1: COMMA@2..3 "," [] []
       2: (empty)
     2: R_BRACK@3..4 "]" [] []
-  1: EOF@4..4 "" [] []
-
-```
-
-## Diagnostics
-
-```
-array_number_and_comma.json:1:4 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+  1: EOF@4..5 "" [Newline("\n")] []
 
-  × expected an array, an object, or a literal but instead found ']'
-
-  > 1 │ [1,]
-      │    ^
-
-  i Expected an array, an object, or a literal here
-
-  > 1 │ [1,]
-      │    ^
-
 ```
 
 

crates/rome_json_parser/tests/json_test_suite/ok/array_with_extra_one_comma.json

@@ -0,0 +1 @@
+[1,]

crates/rome_json_parser/tests/json_test_suite/ok/array_with_extra_one_comma.json.snap

@@ -0,0 +1,49 @@
+---
+source: crates/rome_json_parser/tests/spec_test.rs
+expression: snapshot
+---
+
+## Input
+
+```json
+[1,]
+
+```
+
+
+## AST
+
+```
+JsonRoot {
+    value: JsonArrayValue {
+        l_brack_token: L_BRACK@0..1 "[" [] [],
+        elements: JsonArrayElementList [
+            JsonNumberValue {
+                value_token: JSON_NUMBER_LITERAL@1..2 "1" [] [],
+            },
+            COMMA@2..3 "," [] [],
+            missing element,
+        ],
+        r_brack_token: R_BRACK@3..4 "]" [] [],
+    },
+    eof_token: EOF@4..5 "" [Newline("\n")] [],
+}
+```
+
+## CST
+
+```
+0: JSON_ROOT@0..5
+  0: JSON_ARRAY_VALUE@0..4
+    0: L_BRACK@0..1 "[" [] []
+    1: JSON_ARRAY_ELEMENT_LIST@1..3
+      0: JSON_NUMBER_VALUE@1..2
+        0: JSON_NUMBER_LITERAL@1..2 "1" [] []
+      1: COMMA@2..3 "," [] []
+      2: (empty)
+    2: R_BRACK@3..4 "]" [] []
+  1: EOF@4..5 "" [Newline("\n")] []
+
+```
+
+

crates/rome_json_parser/tests/json_test_suite/ok/object_trailing_comma.json

@@ -0,0 +1 @@
+{"id":0,}

crates/rome_json_parser/tests/json_test_suite/err/object_trailing_comma.json.snap → crates/rome_json_parser/tests/json_test_suite/ok/object_trailing_comma.json.snap

@@ -7,6 +7,7 @@ expression: snapshot
 
 ```json
 {"id":0,}
+
 ```
 
 
@@ -31,14 +32,14 @@ JsonRoot {
         ],
         r_curly_token: R_CURLY@8..9 "}" [] [],
     },
-    eof_token: EOF@9..9 "" [] [],
+    eof_token: EOF@9..10 "" [Newline("\n")] [],
 }
 ```
 
 ## CST
 
 ```
-0: JSON_ROOT@0..9
+0: JSON_ROOT@0..10
   0: JSON_OBJECT_VALUE@0..9
     0: L_CURLY@0..1 "{" [] []
     1: JSON_MEMBER_LIST@1..8
@@ -51,25 +52,8 @@ JsonRoot {
       1: COMMA@7..8 "," [] []
       2: (empty)
     2: R_CURLY@8..9 "}" [] []
-  1: EOF@9..9 "" [] []
-
-```
-
-## Diagnostics
-
-```
-object_trailing_comma.json:1:9 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
+  1: EOF@9..10 "" [Newline("\n")] []
 
-  × expected a property but instead found '}'
-
-  > 1 │ {"id":0,}
-      │         ^
-
-  i Expected a property here
-
-  > 1 │ {"id":0,}
-      │         ^
-
 ```