jsondocck: catch and error on deprecated syntax

Author: yotamofek

src/tools/jsondocck/src/main.rs

@@ -166,6 +166,18 @@ static LINE_PATTERN: LazyLock<Regex> = LazyLock::new(|| {
     .unwrap()
 });
 
+static DEPRECATED_LINE_PATTERN: LazyLock<Regex> = LazyLock::new(|| {
+    RegexBuilder::new(
+        r#"
+        //\s+@
+    "#,
+    )
+    .ignore_whitespace(true)
+    .unicode(true)
+    .build()
+    .unwrap()
+});
+
 fn print_err(msg: &str, lineno: usize) {
     eprintln!("Invalid command: {} on line {}", msg, lineno)
 }
@@ -183,6 +195,12 @@ fn get_commands(template: &str) -> Result<Vec<Command>, ()> {
     for (lineno, line) in file.split('\n').enumerate() {
         let lineno = lineno + 1;
 
+        if DEPRECATED_LINE_PATTERN.is_match(line) {
+            print_err("Deprecated command syntax, replace `// @` with `//@ `", lineno);
+            errors = true;
+            continue;
+        }
+
         let Some(cap) = LINE_PATTERN.captures(line) else {
             continue;
         };