1 files changed, 32 insertions, 0 deletions
diff --git a/src/diagnostics/empty_tag_name.rs b/src/diagnostics/empty_tag_name.rs
new file mode 100644
index 0000000..e8fdb07
--- /dev/null
+++ b/src/diagnostics/empty_tag_name.rs
@@ -0,0 +1,32 @@
+use miette::Diagnostic;
+use thiserror::Error;
+
+use crate::{
+	diagnostics::TokenDiagnostic,
+	tokenize::{Span, Token, TokenType},
+};
+
+#[derive(Error, Debug, Diagnostic)]
+#[error("Tag names must be alphabetic")]
+#[diagnostic(code(EmptyTagName), severity(Error))]
+pub struct EmptyTagName {
+	#[label(primary, "all tags must have a name")]
+	tag: Span,
+}
+
+impl TokenDiagnostic for EmptyTagName {
+	fn handle_token(token: &Token<'_>) -> Option<Self> {
+		let TokenType::Tag {
+			lowercase_tag_name, ..
+		} = token.ty
+		else {
+			return None;
+		};
+
+		if !lowercase_tag_name.is_empty() {
+			return None;
+		}
+
+		Some(Self { tag: token.span })
+	}
+}