appview/blob: fix code escaping and syntax highlight

appview/pages/pages.go

···
 package pages
 
 import (
+	"bytes"
 	"embed"
 	"fmt"
+	"html"
 	"html/template"
 	"io"
 	"io/fs"
 	"log"
 	"net/http"
 	"path"
+	"path/filepath"
 	"strings"
 
+	chromahtml "github.com/alecthomas/chroma/v2/formatters/html"
+	"github.com/alecthomas/chroma/v2/lexers"
+	"github.com/alecthomas/chroma/v2/styles"
 	"github.com/dustin/go-humanize"
 	"github.com/sotangled/tangled/appview/auth"
 	"github.com/sotangled/tangled/appview/db"
···
 		"splitN": func(s, sep string, n int) []string {
 			return strings.SplitN(s, sep, n)
 		},
-		"escapeHtml": func(s string) string {
-			return template.HTMLEscapeString(s)
+		"escapeHtml": func(s string) template.HTML {
+			if s == "" {
+				return template.HTML("<br>")
+			}
+			return template.HTML(s)
+		},
+		"unescapeHtml": func(s string) string {
+			return html.UnescapeString(s)
 		},
 		"nl2br": func(text string) template.HTML {
 			return template.HTML(strings.Replace(template.HTMLEscapeString(text), "\n", "<br>", -1))
···
 }
 
 func (p *Pages) RepoBlob(w io.Writer, params RepoBlobParams) error {
+	if params.Lines < 5000 {
+		c := params.Contents
+		style := styles.Get("xcode")
+		formatter := chromahtml.New(
+			chromahtml.InlineCode(true),
+			chromahtml.WithLineNumbers(true),
+			chromahtml.WithLinkableLineNumbers(true, "L"),
+			chromahtml.Standalone(false),
+		)
+
+		lexer := lexers.Get(filepath.Base(params.Path))
+		if lexer == nil {
+			lexer = lexers.Fallback
+		}
+
+		iterator, err := lexer.Tokenise(nil, c)
+		if err != nil {
+			return fmt.Errorf("chroma tokenize: %w", err)
+		}
+
+		var code bytes.Buffer
+		err = formatter.Format(&code, style, iterator)
+		if err != nil {
+			return fmt.Errorf("chroma format: %w", err)
+		}
+
+		params.Contents = code.String()
+	}
+
 	params.Active = "overview"
 	return p.executeRepo("repo/blob", w, params)
 }

appview/pages/templates/repo/blob.html

···
 {{ define "repoContent" }}
-{{ $lines := split .Contents }}
-{{ $tot_lines := len $lines }}
-{{ $tot_chars := len (printf "%d" $tot_lines) }}
-{{ $code_number_style := "text-gray-400 left-0 bg-white text-right mr-2 select-none" }}
-{{ $linkstyle := "no-underline hover:underline" }}
-<div class="pb-2 text-base">
-  <div class="flex justify-between">
-    <div id="breadcrumbs">
-      {{ range $idx, $value := .BreadCrumbs }}
-      {{ if ne $idx (sub (len $.BreadCrumbs) 1) }}
-      <a href="{{ index . 1}}" class="text-bold text-gray-500 {{ $linkstyle }}">{{ index . 0 }}</a> /
-      {{ else }}
-      <span class="text-bold text-gray-500">{{ index . 0 }}</span>
-      {{ end }}
-      {{ end }}
+    {{ $lines := split .Contents }}
+    {{ $tot_lines := len $lines }}
+    {{ $tot_chars := len (printf "%d" $tot_lines) }}
+    {{ $code_number_style := "text-gray-400 left-0 bg-white text-right mr-6 select-none" }}
+    {{ $linkstyle := "no-underline hover:underline" }}
+    <div class="pb-2 text-base">
+        <div class="flex justify-between">
+            <div id="breadcrumbs">
+                {{ range $idx, $value := .BreadCrumbs }}
+                    {{ if ne $idx (sub (len $.BreadCrumbs) 1) }}
+                        <a
+                            href="{{ index . 1 }}"
+                            class="text-bold text-gray-500 {{ $linkstyle }}"
+                            >{{ index . 0 }}</a
+                        >
+                        /
+                    {{ else }}
+                        <span class="text-bold text-gray-500"
+                            >{{ index . 0 }}</span
+                        >
+                    {{ end }}
+                {{ end }}
+            </div>
+            <div id="file-info">
+                {{ .Lines }} lines
+                <span class="select-none px-2 [&:before]:content-['·']"></span>
+                {{ byteFmt .SizeHint }}
+            </div>
+        </div>
     </div>
-    <div id="file-info">
-        {{ .Lines }} lines
-        <span class="select-none px-2 [&:before]:content-['·']"></span>
-        {{ byteFmt .SizeHint }}
-    </div>
-  </div>
-</div>
-
-{{ if eq .Lines 0 }}
-<p class="text-center text-gray-400">This file is empty.</p>
-{{ else }}
-
-{{ if .IsBinary }}<p class="text-center text-gray-400">This is a binary file and will not be displayed.</p>{{ else }}
-<pre class="font-mono text-sm overflow-auto relative text-ellipsis"><code>{{ range $idx, $line := $lines }}<span class="flex">
-  <span class="{{ $code_number_style }}" style="min-width: {{$tot_chars}}ch;">{{ add $idx 1 }}</span>
-  <span class="whitespace-pre">{{ escapeHtml $line }}</span></span>{{ else }}<em class="text-gray-400">this file is empty</em>{{ end }}</code></pre>{{ end}}
+    {{ if .IsBinary }}
+        <p class="text-center text-gray-400">
+            This is a binary file and will not be displayed.
+        </p>
+    {{ else }}
+        <div class="overflow-auto relative text-ellipsis">
+            {{ range $idx, $line := $lines }}
+                <div class="flex">
+                    <span
+                        class="{{ $code_number_style }}"
+                        style="min-width: {{ $tot_chars }}ch;"
+                        >{{ add $idx 1 }}</span
+                    >
+                    <div class="whitespace-pre">{{ $line | escapeHtml }}</div>
+                </div>
+            {{ end }}
+        </div>
+    {{ end }}
 {{ end }}
-{{ end }}

go.mod

···
 	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/ProtonMail/go-crypto v1.0.0 // indirect
 	github.com/acomagu/bufpipe v1.0.4 // indirect
+	github.com/alecthomas/chroma/v2 v2.15.0 // indirect
 	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
···
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cloudflare/circl v1.4.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/dlclark/regexp2 v1.11.5 // indirect
 	github.com/emirpasic/gods v1.18.1 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect

go.sum

···
 github.com/ProtonMail/go-crypto v1.0.0/go.mod h1:EjAoLdwvbIOoOQr3ihjnSoLZRtE8azugULFRteWMNc0=
 github.com/acomagu/bufpipe v1.0.4 h1:e3H4WUzM3npvo5uv95QuJM3cQspFNtFBzvJ2oNjKIDQ=
 github.com/acomagu/bufpipe v1.0.4/go.mod h1:mxdxdup/WdsKVreO5GpW4+M/1CE2sMG4jeGJ2sYmHc4=
+github.com/alecthomas/chroma/v2 v2.15.0 h1:LxXTQHFoYrstG2nnV9y2X5O94sOBzf0CIUpSTbpxvMc=
+github.com/alecthomas/chroma/v2 v2.15.0/go.mod h1:gUhVLrPDXPtp/f+L1jo9xepo9gL4eLwRuGAunSZMkio=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be h1:9AeTilPcZAjCFIImctFaOjnTIavg87rW78vTPkQqLI8=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be/go.mod h1:ySMOLuWl6zY27l47sB3qLNK6tF2fkHG55UZxx8oIVo4=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
···
 github.com/dgraph-io/ristretto v0.2.0/go.mod h1:8uBHCU/PBV4Ag0CJrP47b9Ofby5dqWNh4FicAdoqFNU=
 github.com/dgryski/go-farm v0.0.0-20200201041132-a6ae2369ad13 h1:fAjc9m62+UWV/WAFKLNi6ZS0675eEUC9y3AlwSbQu1Y=
 github.com/dgryski/go-farm v0.0.0-20200201041132-a6ae2369ad13/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
+github.com/dlclark/regexp2 v1.11.5 h1:Q/sSnsKerHeCkc/jSTNq1oCm7KiVgUMZRDUoRu0JQZQ=
+github.com/dlclark/regexp2 v1.11.5/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/emirpasic/gods v1.18.1 h1:FXtiHYKDGKCW2KzwZKx0iC0PQmdlorYgdFG9jPXJ1Bc=

knotserver/routes.go

···
 	}
 
 	bytes := []byte(contents)
-	safe := string(sanitize(bytes))
+	// safe := string(sanitize(bytes))
 	sizeHint := len(bytes)
 
 	resp := types.RepoBlobResponse{
 		Ref:      ref,
-		Contents: string(safe),
+		Contents: string(bytes),
 		Path:     treePath,
 		IsBinary: isBinaryFile,
 		SizeHint: uint64(sizeHint),