feat: Allow properties with empty values

.editorconfig

@@ -6,6 +6,11 @@ end_of_line = lf
 insert_final_newline = true
 trim_trailing_whitespace = true
 
+[test/**/*.txt]
+trim_trailing_whitespace = false
+indent_style = space
+indent_size = 2
+
 [*.{json,toml,yml,gyp}]
 indent_style = space
 indent_size = 2

grammar.js

@@ -83,7 +83,7 @@ module.exports = grammar({
         field('key', alias($._key_name_trimmed, $.identifier)),
         '=',
         /[ \t]*/, // Eat all the leading white-space
-        field('value', $._value),
+        field('value', optional($._value)),
         $._newline,
       ),
 

queries/highlights.scm

@@ -33,7 +33,8 @@
 (escaped_character) @string.special
 
 (pair
-  key: (identifier) @property)
+  key: (identifier) @property
+  value: (_)? @string)
 
 (boolean) @boolean
 (integer) @number

src/scanner.c

@@ -50,7 +50,10 @@ static inline bool parse_key_name(TSLexer *lexer)
 
     while (lexer->lookahead != '=') {
         if (is_newline(lexer->lookahead) || lexer->eof(lexer)) {
-            return false;
+            // NOTE: Tecnically is not valid since there is be no value
+            // on the right side, but it gives better error recovery
+            lexer->result_symbol = KEY_NAME_TRIMMED;
+            return true;
         }
         if (is_space(lexer->lookahead)) {
             lexer->advance(lexer, false);

test/corpus/main.txt

@@ -152,6 +152,31 @@ key = # this is not a comment
       key: (identifier)
       value: (unknown))))
 
+======================================================
+Properties with an empty value
+======================================================
+[a]
+a=
+b =
+ c=
+ d =  
+spaces =     
+------------------------------------------------------
+(document
+  (section
+    (section_name
+      (character))
+    (pair
+      key: (identifier))
+    (pair
+      key: (identifier))
+    (pair
+      key: (identifier))
+    (pair
+      key: (identifier))
+    (pair
+      key: (identifier))))
+
 ======================================================
 Comments
 ======================================================
@@ -338,6 +363,13 @@ Characters after section header
 [a] key = value
 ------------------------------------------------------
 
+======================================================
+Property without '=' and value
+:error
+======================================================
+property
+------------------------------------------------------
+
 ======================================================
 Comment after section header
 :error