fix: fix empty document (fix #5)

Author: g-plane

yaml_parser/src/lib.rs

@@ -375,6 +375,8 @@ fn plain_scalar_one_line(input: &mut Input) -> PResult<()> {
         )),
         plain_scalar_chars,
     )
+        .take()
+        .verify(|line: &str| line != "---")
         .void()
         .parse_next(input)
 }

yaml_parser/tests/pass/two-document-start-markers.snap

@@ -2,9 +2,9 @@
 source: yaml_parser/tests/pass.rs
 ---
 ROOT@0..8
-  DOCUMENT@0..7
+  DOCUMENT@0..3
     DIRECTIVES_END@0..3 "---"
-    WHITESPACE@3..4 "\n"
-    FLOW@4..7
-      PLAIN_SCALAR@4..7 "---"
+  WHITESPACE@3..4 "\n"
+  DOCUMENT@4..7
+    DIRECTIVES_END@4..7 "---"
   WHITESPACE@7..8 "\n"