fix: honour --check when reading from stdin

alecthomas · claude · alecthomas · commit b359e38d1841 · 2026-07-08T12:06:37.000+10:00
The stdin path formatted unconditionally; only the file loop
consulted --check. Piped input now runs the tokenisation check,
reporting as "-" when no --filename is given.

Co-Authored-By: Claude Fable 5 &lt;noreply@anthropic.com&gt;
diff --git a/cmd/chroma/main.go b/cmd/chroma/main.go
@@ -230,6 +230,16 @@ func main() {
 	if len(cli.Files) == 0 {
 		var contents string
 		var lexer chroma.Lexer
+		if cli.Check {
+			contents, lexer, err = prepareLenient(os.Stdin, cli.Filename)
+			ctx.FatalIfErrorf(err)
+			name := cli.Filename
+			if name == "" {
+				name = "-"
+			}
+			check(name, lex(ctx, lexer, contents))
+			return
+		}
 		if cli.Fail {
 			contents, lexer = prepareSpecific(ctx, os.Stdin, cli.Filename, 1024, -1)
 		} else {
