resolve map parsing regression involving trailing commas in doubly nested maps

src/parse/value/parse.rs

@@ -444,12 +444,9 @@ impl<'a> Parser<'a> {
             &|c| matches!(c.peek(), Some(Token { kind: ':', .. }) | Some(Token { kind: ')', .. })),
         )?;
 
-        match self.toks.peek() {
+        match self.toks.next() {
-            Some(Token { kind: ':', .. }) => {
+            Some(Token { kind: ':', .. }) => {}
-                self.toks.next();
-            }
             Some(Token { kind: ')', .. }) => {
-                self.toks.next();
                 return Ok(Spanned {
                     node: IntermediateValue::Value(HigherIntermediateValue::Literal(key.node)),
                     span: key.span,
@@ -509,19 +506,18 @@ impl<'a> Parser<'a> {
                 return Err(("Duplicate key.", key.span).into());
             }
 
-            match self.toks.next() {
+            let found_comma = self.consume_char_if_exists(',');
-                Some(Token { kind: ',', .. }) => {}
+
+            self.whitespace_or_comment();
+
+            match self.toks.peek() {
                 Some(Token { kind: ')', .. }) => {
+                    self.toks.next();
                     break;
                 }
+                Some(..) if found_comma => continue,
                 Some(..) | None => return Err(("expected \")\".", val.span).into()),
             }
-
-            self.whitespace_or_comment();
-
-            while self.consume_char_if_exists(',') {
-                self.whitespace_or_comment();
-            }
         }
         Ok(Spanned {
             node: IntermediateValue::Value(HigherIntermediateValue::Literal(Value::Map(map))),

tests/map.rs

@@ -205,6 +205,16 @@ test!(
     }",
     "a {\n  color: ();\n}\n"
 );
+test!(
+    trailing_comma_in_doubly_nested_map,
+    r#"$a: (
+        foo: (
+            a: b,
+            c: d,
+        )
+    );"#,
+    ""
+);
 error!(
     second_map_value_missing_colon,
     "a {\n  color: (a: b, c", "Error: expected \":\"."