Switch to blackfriday, remove Gemtext instructions

README.md

@@ -47,8 +47,8 @@ some of which are enable by default:
 * MathJax is supported (but needs a separte setup)
 
 See the section on
-[extensions](https://github.com/gomarkdown/markdown#extensions) in the
-Markdown library for information on the various extensions.
+[extensions](https://github.com/russross/blackfriday#extensions) in
+the Blackfriday library for information on the various extensions.
 
 A table with footers and a columnspan:
 
@@ -346,50 +346,8 @@ that matches everything:
 ## Customization (with recompilation)
 
 The Markdown parser can be customized and
-[extensions](https://pkg.go.dev/github.com/gomarkdown/markdown/parser#Extensions)
-can be added. There's an example in the
-[usage](https://github.com/gomarkdown/markdown#usage) section. You'll
-need to make changes to the `viewHandler` yourself.
-
-### Render Gemtext
-
-In a first approximation, Gemtext is valid Markdown except for the
-rocket links (`=>`). Here's how to modify the `loadPage` so that a
-`.gmi` file is loaded if no `.md` is found, and the rocket links are
-translated into Markdown:
-
-```go
-func loadPage(name string) (*Page, error) {
-	filename := name + ".md"
-	body, err := os.ReadFile(filename)
-	if err == nil {
-		return &Page{Title: name, Name: name, Body: body}, nil
-	}
-	filename = name + ".gmi"
-	body, err = os.ReadFile(filename)
-	if err == nil {
-		re := regexp.MustCompile(`(?m)^=>\s*(\S+)\s+(.+)`)
-		body = []byte(re.ReplaceAllString(string(body), `* [$2]($1)`))
-		return &Page{Title: name, Name: name, Body: body}, nil
-	}
-	return nil, err
-}
-```
-
-There is a small problem, however: By default, Markdown expects an
-empty line before a list begins. The following change to `renderHtml`
-uses the `NoEmptyLineBeforeBlock` extension for the parser:
-
-```go
-func (p* Page) renderHtml() {
-    // Here is where a new extension is added!
-	extensions := parser.CommonExtensions | parser.NoEmptyLineBeforeBlock
-	markdownParser := parser.NewWithExtensions(extensions)
-	maybeUnsafeHTML := markdown.ToHTML(p.Body, markdownParser, nil)
-	html := bluemonday.UGCPolicy().SanitizeBytes(maybeUnsafeHTML)
-	p.Html = template.HTML(html);
-}
-```
+[extensions](https://github.com/russross/blackfriday#extensions) can
+be added. You'll need to make changes to `renderHtml` yourself.
 
 ## Understanding search
 

go.mod

@@ -4,16 +4,20 @@ go 1.21.0
 
 require (
 	github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0
-	github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12
 	github.com/microcosm-cc/bluemonday v1.0.25
+	github.com/pemistahl/lingua-go v1.4.0
+	github.com/russross/blackfriday/v2 v2.1.0
 )
 
 require (
 	github.com/aymerick/douceur v0.2.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/gorilla/css v1.0.0 // indirect
-	github.com/pemistahl/lingua-go v1.4.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
+	github.com/stretchr/testify v1.8.4 // indirect
 	golang.org/x/exp v0.0.0-20221106115401-f9659909a136 // indirect
 	golang.org/x/net v0.12.0 // indirect
 	google.golang.org/protobuf v1.31.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,19 +1,27 @@
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0 h1:b+7JSiBM+hnLQjP/lXztks5hnLt1PS46hktG9VOJgzo=
 github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0/go.mod h1:qzKC/DpcxK67zaSHdCmIv3L9WJViHVinYXN2S7l3RM8=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12 h1:uK3X/2mt4tbSGoHvbLBHUny7CKiuwUip3MArtukol4E=
-github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12/go.mod h1:JDGcbDT52eL4fju3sZ4TeHGsQwhG9nbDV21aMyhwPoA=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/gorilla/css v1.0.0 h1:BQqNyPTi50JCFMTw/b67hByjMVXZRwGha6wxVGkeihY=
 github.com/gorilla/css v1.0.0/go.mod h1:Dn721qIggHpt4+EFCcTLTU/vk5ySda2ReITrtgBl60c=
 github.com/microcosm-cc/bluemonday v1.0.25 h1:4NEwSfiJ+Wva0VxN5B8OwMicaJvD8r9tlJWm9rtloEg=
 github.com/microcosm-cc/bluemonday v1.0.25/go.mod h1:ZIOjCQp1OrzBBPIJmfX4qDYFuhU02nx4bn030ixfHLE=
 github.com/pemistahl/lingua-go v1.4.0 h1:ifYhthrlW7iO4icdubwlduYnmwU37V1sbNrwhKBR4rM=
 github.com/pemistahl/lingua-go v1.4.0/go.mod h1:ECuM1Hp/3hvyh7k8aWSqNCPlTxLemFZsRjocUf3KgME=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/shopspring/decimal v1.3.1 h1:2Usl1nmF/WZucqkFZhnfFYxxxu8LG21F6nPQBE5gKV8=
 github.com/shopspring/decimal v1.3.1/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 golang.org/x/exp v0.0.0-20221106115401-f9659909a136 h1:Fq7F/w7MAa1KJ5bt2aJ62ihqp9HDcRuyILskkpIAurw=
 golang.org/x/exp v0.0.0-20221106115401-f9659909a136/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/net v0.12.0 h1:cfawfvKITfUsFCeJIHJrbSxpeu/E81khclypR0GVT50=
@@ -22,3 +30,6 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
 google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

page.go

@@ -3,11 +3,9 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"github.com/gomarkdown/markdown"
-	"github.com/gomarkdown/markdown/ast"
-	"github.com/gomarkdown/markdown/parser"
 	"github.com/microcosm-cc/bluemonday"
 	"github.com/pemistahl/lingua-go"
+	"github.com/russross/blackfriday/v2"
 	"html/template"
 	"os"
 	"path/filepath"
@@ -103,7 +101,7 @@ func (p *Page) handleTitle(replace bool) {
 
 // renderHtml renders the Page.Body to HTML and sets Page.Html.
 func (p *Page) renderHtml() {
-	maybeUnsafeHTML := markdown.ToHTML(p.Body, nil, nil)
+	maybeUnsafeHTML := blackfriday.Run(p.Body)
 	p.Html = sanitizeBytes(maybeUnsafeHTML)
 	p.Language = language(p.plainText())
 }
@@ -112,26 +110,30 @@ func (p *Page) renderHtml() {
 // ignoring all the Markdown and all the newlines. The result is one
 // long single line of text.
 func (p *Page) plainText() string {
-	parser := parser.New()
-	doc := markdown.Parse(p.Body, parser)
+	optList := []blackfriday.Option{blackfriday.WithExtensions(blackfriday.CommonExtensions)}
+	parser := blackfriday.New(optList...)
+	ast := parser.Parse(p.Body)
 	text := []byte("")
-	ast.WalkFunc(doc, func(node ast.Node, entering bool) ast.WalkStatus {
-		if entering && node.AsLeaf() != nil {
-			text = append(text, node.AsLeaf().Literal...)
-			text = append(text, []byte(" ")...)
+	ast.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+		if entering && node.Type == blackfriday.Text {
+			s := node.Literal
+			if len(s) == 0 {
+				return blackfriday.GoToNext
+			}
+			// Some Markdown still contains newlines
+			for i, c := range s {
+				if c == '\n' {
+					s[i] = ' '
+				}
+			}
+			if len(text) > 0 && text[len(text)-1] != ' ' && s[0] != ' ' {
+				text = append(text, ' ')
+			}
+
+			text = append(text, s...)
 		}
-		return ast.GoToNext
+		return blackfriday.GoToNext
 	})
-	// Some Markdown still contains newlines
-	for i, c := range text {
-		if c == '\n' {
-			text[i] = ' '
-		}
-	}
-	// Remove trailing space
-	for len(text) > 0 && text[len(text)-1] == ' ' {
-		text = text[0 : len(text)-1]
-	}
 	return string(text)
 }
 

page_test.go

@@ -2,8 +2,9 @@ package main
 
 import (
 	"os"
-	"strings"
+	"regexp"
 	"testing"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestPageTitle(t *testing.T) {
@@ -12,19 +13,10 @@ My back aches for you
 I sit, stare and type for hours
 But yearn for blue sky`)}
 	p.handleTitle(false)
-	if p.Title != "Ache" {
-		t.Logf("The page title was not extracted correctly: %s", p.Title)
-		t.Fail()
-	}
-	if !strings.HasPrefix(string(p.Body), "# Ache") {
-		t.Logf("The page title was removed: %s", p.Body)
-		t.Fail()
-	}
+	assert.Equal(t, "Ache", p.Title)
+	assert.Regexp(t, regexp.MustCompile("^# Ache"), string(p.Body))
 	p.handleTitle(true)
-	if !strings.HasPrefix(string(p.Body), "My back") {
-		t.Logf("The page title was not removed: %s", p.Body)
-		t.Fail()
-	}
+	assert.Regexp(t, regexp.MustCompile("^My back"), string(p.Body))
 }
 
 func TestPagePlainText(t *testing.T) {
@@ -32,12 +24,8 @@ func TestPagePlainText(t *testing.T) {
 The air will not come
 To inhale is an effort
 The summer heat kills`)}
-	s := p.plainText()
 	r := "Water The air will not come To inhale is an effort The summer heat kills"
-	if s != r {
-		t.Logf("The plain text version is wrong: %s", s)
-		t.Fail()
-	}
+	assert.Equal(t, r, p.plainText())
 }
 
 func TestPageHtml(t *testing.T) {
@@ -46,17 +34,13 @@ Silver leaves shine bright
 They droop, boneless, weak and sad
 A cruel sun stares down`)}
 	p.renderHtml()
-	s := string(p.Html)
 	r := `<h1>Sun</h1>
 
 <p>Silver leaves shine bright
 They droop, boneless, weak and sad
 A cruel sun stares down</p>
 `
-	if s != r {
-		t.Logf("The HTML is wrong: %s", s)
-		t.Fail()
-	}
+	assert.Equal(t, r, string(p.Html))
 }
 
 func TestPageDir(t *testing.T) {
@@ -68,10 +52,8 @@ A slow shuffle in the dark
 Moonlight floods the aisle`)}
 	p.save()
 	o, err := loadPage("testdata/moon")
-	if err != nil || string(o.Body) != string(p.Body) {
-		t.Logf("File in subdirectory not loaded: %s", p.Name)
-		t.Fail()
-	}
+	assert.NoError(t, err, "load page")
+	assert.Equal(t, p.Body, o.Body)
 	t.Cleanup(func() {
 		_ = os.RemoveAll("testdata")
 	})
@@ -82,8 +64,5 @@ func TestLanguage(t *testing.T) {
 My back hurts at night
 My shoulders won't budge today
 Winter bones I say`)
-	if l != "en" {
-		t.Logf("Language detected: %s", l)
-		t.Fail()
-	}
+	assert.Equal(t, "en", l)
 }