Migrate to Goldmark

go.mod

@@ -5,19 +5,21 @@ go 1.16
 require (
 	github.com/BurntSushi/toml v1.0.0
 	github.com/Masterminds/sprig/v3 v3.2.2
-	github.com/gomarkdown/markdown v0.0.0-20220310201231-552c6011c0b8
+	github.com/gomarkdown/markdown v0.0.0-20221013030248-663e2500819c
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/grokify/html-strip-tags-go v0.0.1
 	github.com/hexops/gotextdiff v1.0.3
 	github.com/huandu/xstrings v1.3.2 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/kr/pretty v0.3.0 // indirect
-	github.com/mattn/go-runewidth v0.0.13 // indirect
+	github.com/mattn/go-runewidth v0.0.14 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/niklasfasching/go-org v1.6.2
 	github.com/olekukonko/tablewriter v0.0.5
+	github.com/rivo/uniseg v0.4.3 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
 	github.com/spf13/cast v1.4.1 // indirect
+	github.com/yuin/goldmark v1.5.3
 	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd // indirect
 	golang.org/x/net v0.0.0-20220225172249-27dd8689420f // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect

go.sum

@@ -12,8 +12,8 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 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/dlclark/regexp2 v1.4.0/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
-github.com/gomarkdown/markdown v0.0.0-20220310201231-552c6011c0b8 h1:YVvt637ygnOO9qjLBVmPOvrUmCz/i8YECSu/8UlOQW0=
-github.com/gomarkdown/markdown v0.0.0-20220310201231-552c6011c0b8/go.mod h1:JDGcbDT52eL4fju3sZ4TeHGsQwhG9nbDV21aMyhwPoA=
+github.com/gomarkdown/markdown v0.0.0-20221013030248-663e2500819c h1:iyaGYbCmcYK0Ja9a3OUa2Fo+EaN0cbLu0eKpBwPFzc8=
+github.com/gomarkdown/markdown v0.0.0-20221013030248-663e2500819c/go.mod h1:JDGcbDT52eL4fju3sZ4TeHGsQwhG9nbDV21aMyhwPoA=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
@@ -36,8 +36,8 @@ github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
-github.com/mattn/go-runewidth v0.0.13 h1:lTGmDsbAYt5DmK6OnoV7EuIF1wEIFAcxld6ypU4OSgU=
-github.com/mattn/go-runewidth v0.0.13/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mattn/go-runewidth v0.0.14 h1:+xnbZSEeDbOIg5/mE6JF0w6n9duR1l3/WmbinWVwUuU=
+github.com/mattn/go-runewidth v0.0.14/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mitchellh/copystructure v1.0.0/go.mod h1:SNtv71yrdKgLRyLFxmLdkAbkKEFWgYaq1OVrnRcwhnw=
 github.com/mitchellh/copystructure v1.2.0 h1:vpKXTN4ewci03Vljg/q9QvCGUDttBOGBIa15WveJJGw=
 github.com/mitchellh/copystructure v1.2.0/go.mod h1:qLl+cE2AmVv+CoeAwDPye/v+N2HKCj9FbZEVFJRxO9s=
@@ -50,8 +50,9 @@ github.com/olekukonko/tablewriter v0.0.5 h1:P2Ga83D34wi1o9J6Wh1mRuqd4mF/x/lgBS7N
 github.com/olekukonko/tablewriter v0.0.5/go.mod h1:hPp6KlRPjbx+hW8ykQs1w3UBbZlj6HuIJcUGPhkA7kY=
 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/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.3 h1:utMvzDsuh3suAEnhH0RdHmoPbU648o6CvXxTx4SBMOw=
+github.com/rivo/uniseg v0.4.3/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/rogpeppe/go-internal v1.6.1 h1:/FiVV8dS/e+YqF2JvO3yXRFbBLTIuSDkuC7aBOAvL+k=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/shopspring/decimal v1.2.0/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=
@@ -65,6 +66,8 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/yuin/goldmark v1.5.3 h1:3HUJmBFbQW9fhQOzMgseU134xfi6hU+mjWywx5Ty+/M=
+github.com/yuin/goldmark v1.5.3/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200414173820-0848c9571904/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd h1:XcWmESyNjXJMLahc3mqVQJcgSTDxFxhETVlfk9uGc38=

internal/renderer2/doc.go

@@ -0,0 +1,18 @@
+// This file is part of gmnhg.
+
+// gmnhg is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// gmnhg is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with gmnhg. If not, see <https://www.gnu.org/licenses/>.
+
+// Package renderer contains an implementation of markdown =>
+// text/gemini renderer for github.com/yuin/goldmark.
+package renderer

internal/renderer2/renderer.go

@@ -0,0 +1,37 @@
+// This file is part of gmnhg.
+
+// gmnhg is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// gmnhg is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with gmnhg. If not, see <https://www.gnu.org/licenses/>.
+
+package renderer
+
+import (
+	"io"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+)
+
+// Renderer implements renderer.Renderer.
+type Renderer struct{}
+
+// NewRenderer returns a new Renderer.
+func NewRenderer() Renderer {
+	return Renderer{}
+}
+
+func (r Renderer) Render(w io.Writer, source []byte, node ast.Node) error {
+	return nil
+}
+
+func (r Renderer) AddOptions(...renderer.Option) {}

render.go

@@ -23,6 +23,10 @@ import (
 	"github.com/gomarkdown/markdown"
 	"github.com/gomarkdown/markdown/parser"
 	"github.com/tdemin/gmnhg/internal/renderer"
+	renderer2 "github.com/tdemin/gmnhg/internal/renderer2"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/text"
 )
 
 // Settings is a bitmask for renderer preferences.
@@ -40,19 +44,44 @@ const (
 
 var trailing = []byte("\n\n")
 
+func stripTrailingNewlines(content []byte) []byte {
+	stripped := content
+	for li := bytes.LastIndex(stripped, trailing); li != -1; li = bytes.LastIndex(stripped, trailing) {
+		if li != len(stripped)-len(trailing) {
+			break
+		}
+		stripped = stripped[:len(stripped)-1]
+	}
+	return stripped
+}
+
 // RenderMarkdown converts Markdown text to Gemtext using gomarkdown. It
 // ignores front matter if any has been provided in the text.
 func RenderMarkdown(md []byte, settings Settings) (geminiText []byte, err error) {
 	ast := markdown.Parse(md, parser.NewWithExtensions(parser.CommonExtensions|
 		parser.NoEmptyLineBeforeBlock|
 		parser.Footnotes))
 	content := markdown.Render(ast, renderer.NewRenderer())
-	// strip trailing newlines if any
-	for li := bytes.LastIndex(content, trailing); li != -1; li = bytes.LastIndex(content, trailing) {
-		if li != len(content)-len(trailing) {
-			break
-		}
-		content = content[:len(content)-1]
+	return stripTrailingNewlines(content), nil
+}
+
+// RenderMarkdown2 converts Markdown text to Gemtext using Goldmark. It
+// ignores front matter if any has been provided in the text.
+func RenderMarkdown2(md []byte, settings Settings) (geminiText []byte, err error) {
+	r := renderer2.NewRenderer()
+	gm := goldmark.New(
+		goldmark.WithExtensions(
+			extension.GFM,
+			extension.Footnote,
+			extension.DefinitionList,
+		),
+		goldmark.WithRenderer(r),
+	)
+	ast := gm.Parser().Parse(text.NewReader(md))
+
+	buf := bytes.Buffer{}
+	if err := gm.Renderer().Render(&buf, md, ast); err != nil {
+		return nil, err
 	}
-	return content, nil
+	return stripTrailingNewlines(buf.Bytes()), nil
 }

render_test.go

@@ -75,3 +75,29 @@ func TestRenderer(t *testing.T) {
 		}
 	}
 }
+
+func TestRenderer2(t *testing.T) {
+	for _, testName := range fileList {
+		t.Logf("testing %s", testName)
+		mdContents, err := ioutil.ReadFile(path.Join("testdata", testName+".md"))
+		if err != nil {
+			t.Fatalf("failed to open Markdown test %s: %v", testName, err)
+		}
+		gmiContents, err := ioutil.ReadFile(path.Join("testdata", testName+".gmi"))
+		if err != nil {
+			t.Logf("%s: cannot open Gemtext file, skipping: %v", testName, err)
+			continue
+		}
+		content, _ := gmnhg.ParseMetadata(mdContents)
+		geminiContent, err := RenderMarkdown2(content, Defaults)
+		if err != nil {
+			t.Errorf("failed to convert %s Markdown to Gemtext: %v", testName, err)
+		}
+		if !bytes.Equal(geminiContent, gmiContents) {
+			diff := myers.ComputeEdits(span.URIFromPath("a.gmi"),
+				string(geminiContent), string(gmiContents))
+			t.Errorf("content mismatch on %s, diff:\n%s", testName,
+				gotextdiff.ToUnified("a.gmi", "b.gmi", string(geminiContent), diff))
+		}
+	}
+}