fix: register chroma style once

don't register chroma style if it's already registered

this could cause a "concurrent map writes" fatal error when used in a
concurrent setting like a bubbletea wish app. use a package-wide mutex
to protect registering a new style.

ansi/codeblock.go

@@ -2,13 +2,25 @@ package ansi
 
 import (
  "io"
+ "sync"
 
  "github.com/alecthomas/chroma"
  "github.com/alecthomas/chroma/quick"
  "github.com/alecthomas/chroma/styles"
  "github.com/muesli/reflow/indent"
 )
 
+const (
+ // The chroma style theme name used for rendering.
+ chromaStyleTheme = "charm"
+)
+
+var (
+ // mutex for synchronizing access to the chroma style registry.
+ // Related https://github.com/alecthomas/chroma/pull/650
+ mutex = sync.Mutex{}
+)
+
 // A CodeBlockElement is used to render code blocks.
 type CodeBlockElement struct {
  Code string
@@ -64,41 +76,47 @@ func (e *CodeBlockElement) Render(w io.Writer, ctx RenderContext) error {
  theme := rules.Theme
 
  if rules.Chroma != nil && ctx.options.ColorProfile > 1 {
- theme = "charm"
- styles.Register(chroma.MustNewStyle("charm",
- chroma.StyleEntries{
- chroma.Text: chromaStyle(rules.Chroma.Text),
- chroma.Error: chromaStyle(rules.Chroma.Error),
- chroma.Comment: chromaStyle(rules.Chroma.Comment),
- chroma.CommentPreproc: chromaStyle(rules.Chroma.CommentPreproc),
- chroma.Keyword: chromaStyle(rules.Chroma.Keyword),
- chroma.KeywordReserved: chromaStyle(rules.Chroma.KeywordReserved),
- chroma.KeywordNamespace: chromaStyle(rules.Chroma.KeywordNamespace),
- chroma.KeywordType: chromaStyle(rules.Chroma.KeywordType),
- chroma.Operator: chromaStyle(rules.Chroma.Operator),
- chroma.Punctuation: chromaStyle(rules.Chroma.Punctuation),
- chroma.Name: chromaStyle(rules.Chroma.Name),
- chroma.NameBuiltin: chromaStyle(rules.Chroma.NameBuiltin),
- chroma.NameTag: chromaStyle(rules.Chroma.NameTag),
- chroma.NameAttribute: chromaStyle(rules.Chroma.NameAttribute),
- chroma.NameClass: chromaStyle(rules.Chroma.NameClass),
- chroma.NameConstant: chromaStyle(rules.Chroma.NameConstant),
- chroma.NameDecorator: chromaStyle(rules.Chroma.NameDecorator),
- chroma.NameException: chromaStyle(rules.Chroma.NameException),
- chroma.NameFunction: chromaStyle(rules.Chroma.NameFunction),
- chroma.NameOther: chromaStyle(rules.Chroma.NameOther),
- chroma.Literal: chromaStyle(rules.Chroma.Literal),
- chroma.LiteralNumber: chromaStyle(rules.Chroma.LiteralNumber),
- chroma.LiteralDate: chromaStyle(rules.Chroma.LiteralDate),
- chroma.LiteralString: chromaStyle(rules.Chroma.LiteralString),
- chroma.LiteralStringEscape: chromaStyle(rules.Chroma.LiteralStringEscape),
- chroma.GenericDeleted: chromaStyle(rules.Chroma.GenericDeleted),
- chroma.GenericEmph: chromaStyle(rules.Chroma.GenericEmph),
- chroma.GenericInserted: chromaStyle(rules.Chroma.GenericInserted),
- chroma.GenericStrong: chromaStyle(rules.Chroma.GenericStrong),
- chroma.GenericSubheading: chromaStyle(rules.Chroma.GenericSubheading),
- chroma.Background: chromaStyle(rules.Chroma.Background),
- }))
+ theme = chromaStyleTheme
+ mutex.Lock()
+ // Don't register the style if it's already registered.
+ _, ok := styles.Registry[theme]
+ if !ok {
+ styles.Register(chroma.MustNewStyle(theme,
+ chroma.StyleEntries{
+ chroma.Text: chromaStyle(rules.Chroma.Text),
+ chroma.Error: chromaStyle(rules.Chroma.Error),
+ chroma.Comment: chromaStyle(rules.Chroma.Comment),
+ chroma.CommentPreproc: chromaStyle(rules.Chroma.CommentPreproc),
+ chroma.Keyword: chromaStyle(rules.Chroma.Keyword),
+ chroma.KeywordReserved: chromaStyle(rules.Chroma.KeywordReserved),
+ chroma.KeywordNamespace: chromaStyle(rules.Chroma.KeywordNamespace),
+ chroma.KeywordType: chromaStyle(rules.Chroma.KeywordType),
+ chroma.Operator: chromaStyle(rules.Chroma.Operator),
+ chroma.Punctuation: chromaStyle(rules.Chroma.Punctuation),
+ chroma.Name: chromaStyle(rules.Chroma.Name),
+ chroma.NameBuiltin: chromaStyle(rules.Chroma.NameBuiltin),
+ chroma.NameTag: chromaStyle(rules.Chroma.NameTag),
+ chroma.NameAttribute: chromaStyle(rules.Chroma.NameAttribute),
+ chroma.NameClass: chromaStyle(rules.Chroma.NameClass),
+ chroma.NameConstant: chromaStyle(rules.Chroma.NameConstant),
+ chroma.NameDecorator: chromaStyle(rules.Chroma.NameDecorator),
+ chroma.NameException: chromaStyle(rules.Chroma.NameException),
+ chroma.NameFunction: chromaStyle(rules.Chroma.NameFunction),
+ chroma.NameOther: chromaStyle(rules.Chroma.NameOther),
+ chroma.Literal: chromaStyle(rules.Chroma.Literal),
+ chroma.LiteralNumber: chromaStyle(rules.Chroma.LiteralNumber),
+ chroma.LiteralDate: chromaStyle(rules.Chroma.LiteralDate),
+ chroma.LiteralString: chromaStyle(rules.Chroma.LiteralString),
+ chroma.LiteralStringEscape: chromaStyle(rules.Chroma.LiteralStringEscape),
+ chroma.GenericDeleted: chromaStyle(rules.Chroma.GenericDeleted),
+ chroma.GenericEmph: chromaStyle(rules.Chroma.GenericEmph),
+ chroma.GenericInserted: chromaStyle(rules.Chroma.GenericInserted),
+ chroma.GenericStrong: chromaStyle(rules.Chroma.GenericStrong),
+ chroma.GenericSubheading: chromaStyle(rules.Chroma.GenericSubheading),
+ chroma.Background: chromaStyle(rules.Chroma.Background),
+ }))
+ }
+ mutex.Unlock()
  }
 
  iw := indent.NewWriterPipe(w, indentation+margin, func(wr io.Writer) {