Add support for rendering terminal output with colors (#19497)

3 files changed, 147 insertions, 0 deletions

diff --git a/modules/markup/console/console.go b/modules/markup/console/console.go
new file mode 100644
index 0000000000..b59594acb7
--- /dev/null
+++ b/modules/markup/console/console.go
@@ -0,0 +1,95 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package console
+
+import (
+	"bytes"
+	"io"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/setting"
+
+	trend "github.com/buildkite/terminal-to-html/v3"
+	"github.com/go-enry/go-enry/v2"
+)
+
+// MarkupName describes markup's name
+var MarkupName = "console"
+
+func init() {
+	markup.RegisterRenderer(Renderer{})
+}
+
+// Renderer implements markup.Renderer
+type Renderer struct{}
+
+// Name implements markup.Renderer
+func (Renderer) Name() string {
+	return MarkupName
+}
+
+// NeedPostProcess implements markup.Renderer
+func (Renderer) NeedPostProcess() bool { return false }
+
+// Extensions implements markup.Renderer
+func (Renderer) Extensions() []string {
+	return []string{".sh-session"}
+}
+
+// SanitizerRules implements markup.Renderer
+func (Renderer) SanitizerRules() []setting.MarkupSanitizerRule {
+	return []setting.MarkupSanitizerRule{
+		{Element: "span", AllowAttr: "class", Regexp: regexp.MustCompile(`^term-((fg[ix]?|bg)\d+|container)$`)},
+	}
+}
+
+// SanitizerDisabled disabled sanitize if return true
+func (Renderer) SanitizerDisabled() bool {
+	return false
+}
+
+// CanRender implements markup.RendererContentDetector
+func (Renderer) CanRender(filename string, input io.Reader) bool {
+	buf, err := io.ReadAll(input)
+	if err != nil {
+		return false
+	}
+	if enry.GetLanguage(filepath.Base(filename), buf) != enry.OtherLanguage {
+		return false
+	}
+	return bytes.ContainsRune(buf, '\x1b')
+}
+
+// Render renders terminal colors to HTML with all specific handling stuff.
+func (Renderer) Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	buf, err := io.ReadAll(input)
+	if err != nil {
+		return err
+	}
+	buf = trend.Render(buf)
+	buf = bytes.ReplaceAll(buf, []byte("\n"), []byte(`<br>`))
+	_, err = output.Write(buf)
+	return err
+}
+
+// Render renders terminal colors to HTML with all specific handling stuff.
+func Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
+	if ctx.Type == "" {
+		ctx.Type = MarkupName
+	}
+	return markup.Render(ctx, input, output)
+}
+
+// RenderString renders terminal colors in string to HTML with all specific handling stuff and return string
+func RenderString(ctx *markup.RenderContext, content string) (string, error) {
+	var buf strings.Builder
+	if err := Render(ctx, strings.NewReader(content), &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
diff --git a/modules/markup/console/console_test.go b/modules/markup/console/console_test.go
new file mode 100644
index 0000000000..282fbb0598
--- /dev/null
+++ b/modules/markup/console/console_test.go
@@ -0,0 +1,31 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package console
+
+import (
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/modules/markup"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRenderConsole(t *testing.T) {
+	var render Renderer
+	kases := map[string]string{
+		"\x1b[37m\x1b[40mnpm\x1b[0m \x1b[0m\x1b[32minfo\x1b[0m \x1b[0m\x1b[35mit worked if it ends with\x1b[0m ok": "<span class=\"term-fg37 term-bg40\">npm</span> <span class=\"term-fg32\">info</span> <span class=\"term-fg35\">it worked if it ends with</span> ok",
+	}
+
+	for k, v := range kases {
+		var buf strings.Builder
+		canRender := render.CanRender("test", strings.NewReader(k))
+		assert.True(t, canRender)
+
+		err := render.Render(&markup.RenderContext{}, strings.NewReader(k), &buf)
+		assert.NoError(t, err)
+		assert.EqualValues(t, v, buf.String())
+	}
+}
diff --git a/modules/markup/renderer.go b/modules/markup/renderer.go
index 53ecbfce2b..6e4ae4e08c 100644
--- a/modules/markup/renderer.go
+++ b/modules/markup/renderer.go
@@ -5,6 +5,7 @@
 package markup
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -93,6 +94,12 @@ type Renderer interface {
 	Render(ctx *RenderContext, input io.Reader, output io.Writer) error
 }
 
+// RendererContentDetector detects if the content can be rendered
+// by specified renderer
+type RendererContentDetector interface {
+	CanRender(filename string, input io.Reader) bool
+}
+
 var (
 	extRenderers = make(map[string]Renderer)
 	renderers    = make(map[string]Renderer)
@@ -117,6 +124,20 @@ func GetRendererByType(tp string) Renderer {
 	return renderers[tp]
 }
 
+// DetectRendererType detects the markup type of the content
+func DetectRendererType(filename string, input io.Reader) string {
+	buf, err := io.ReadAll(input)
+	if err != nil {
+		return ""
+	}
+	for _, renderer := range renderers {
+		if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, bytes.NewReader(buf)) {
+			return renderer.Name()
+		}
+	}
+	return ""
+}
+
 // Render renders markup file to HTML with all specific handling stuff.
 func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
 	if ctx.Type != "" {