commands: Deprecate --omitEmpty on chromastyles command

It's no longer needed -- empty classes are now always omitted.

See  See alecthomas/chroma@5b2a4c5

Author: bep

commands/gen.go

@@ -82,13 +82,13 @@ See https://xyproto.github.io/splash/docs/all.html for a preview of the availabl
 					return err
 				}
 
-				var options []html.Option
 				if omitEmpty {
-					options = append(options, html.WithClasses(true))
-				} else {
-					options = append(options, html.WithAllClasses(true))
+					// See https://github.com/alecthomas/chroma/commit/5b2a4c5a26c503c79bc86ba3c4ae5b330028bd3d
+					hugo.Deprecate("--omitEmpty", "Flag is no longer needed, empty classes are now always omitted.", "v0.149.0")
+				}
+				options := []html.Option{
+					html.WithCSSComments(!omitClassComments),
 				}
-				options = append(options, html.WithCSSComments(!omitClassComments))
 				formatter := html.New(options...)
 
 				w := os.Stdout

testscripts/commands/gen.txt

@@ -15,8 +15,15 @@ stdout 'Generated using: hugo gen chromastyles --style monokai'
 ! hugo gen chromastyles --style __invalid_style__
 stderr 'invalid style: __invalid_style__'
 
-# Issue 13475
+# Not empty classes.
+# From Hugo 0.149.0 empty classes are always removed, so no need for the omitEmpty flag.
 hugo gen chromastyles --style monokai
-stdout '{  }'
-hugo gen chromastyles --omitEmpty --style monokai
-! stdout '\{  \}'
+! stdout '{  }'
+hugo gen chromastyles --omitEmpty --style monokai --logLevel info
+stderr 'INFO  deprecated: --omitEmpty was deprecated'
+
+# Disable class comments.
+hugo gen chromastyles --style monokai
+stdout 'GenericSubheading'
+hugo gen chromastyles --omitClassComments --style monokai
+! stdout 'GenericSubheading'