jsondocck: Use correct index for error message.

aDotInTheVoid · aDotInTheVoid · commit ccc8baf08aa5 · 2024-07-03T19:38:19.000Z
If you misused a count command like `@count $some.selector '"T'"`, you would panic with OOB: ``` thread 'main' panicked at src/tools/jsondocck/src/main.rs:76:92: index out of bounds: the len is 2 but the index is 2 ``` Fixing this typo, we now get. ``` Invalid command: Second argument to @count must be a valid usize (got `"T"`) on line 20 ``` As some point I want to rewrite this code to avoid indexing in general, but this is a nice small fix.
diff --git a/src/tools/jsondocck/src/main.rs b/src/tools/jsondocck/src/main.rs
@@ -56,6 +56,8 @@ pub enum CommandKind {
 
 impl CommandKind {
     fn validate(&self, args: &[String], lineno: usize) -> bool {
+        // FIXME(adotinthevoid): We should "parse, don't validate" here, so we avoid ad-hoc
+        // indexing in check_command.
         let count = match self {
             CommandKind::Has => (1..=2).contains(&args.len()),
             CommandKind::IsMany => args.len() >= 2,
@@ -71,7 +73,7 @@ impl CommandKind {
         if let CommandKind::Count = self {
             if args[1].parse::<usize>().is_err() {
                 print_err(
-                    &format!("Second argument to @count must be a valid usize (got `{}`)", args[2]),
+                    &format!("Second argument to @count must be a valid usize (got `{}`)", args[1]),
                     lineno,
                 );
                 return false;
