Text format: allow empty list syntax in fields (#143)

* Add tests for parsing empty repeated message lists * Support parsing empty repeated value lists
andrewhickman · Feb 6, 2025 · 55a5e14 · 55a5e14
1 parent a6c81bf
commit 55a5e14
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Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/prost-reflect-tests/src/text_format.rs b/prost-reflect-tests/src/text_format.rs
@@ -502,7 +502,7 @@ fn parse_aliased_enum() {
 
 #[test]
 fn parse_array() {
-    let value: ScalarArrays = from_text("double: [1.1, 2f] , float: 3 ; float: inf");
+    let value: ScalarArrays = from_text("double: [1.1, 2f] , float: 3 ; float: inf ; int32: [ ]");
     assert_eq!(
         value,
         ScalarArrays {
@@ -557,6 +557,7 @@ fn parse_complex_type() {
       my_enum: [DEFAULT, FOO]
       my_enum: [2, BAR]
       my_enum: NEG
+      my_enum: []
       optional_enum: FOO
     ",
     );

diff --git a/prost-reflect/src/dynamic/text_format/parse/mod.rs b/prost-reflect/src/dynamic/text_format/parse/mod.rs
@@ -250,7 +250,16 @@ impl<'a> Parser<'a> {
             Some((Token::LeftBracket, _)) => {
                 let start = self.bump();
 
-                let mut result = vec![self.parse_value(kind)?.0];
+                let mut result = Vec::new();
+
+                // Check for empty list first
+                if let Some((Token::RightBracket, _)) = self.peek()? {
+                    let end = self.bump();
+                    return Ok((Value::List(result), join_span(start, end)));
+                }
+
+                result.push(self.parse_value(kind)?.0);
+
                 loop {
                     match self.peek()? {
                         Some((Token::Comma, _)) => {