Use a new vars template implementation

modules/context/repo.go

@@ -29,7 +29,6 @@ import (
 	asymkey_service "code.gitea.io/gitea/services/asymkey"
 
 	"github.com/editorconfig/editorconfig-core-go/v2"
-	"github.com/unknwon/com"
 )
 
 // IssueTemplateDirCandidates issue templates directory
@@ -308,11 +307,11 @@ func EarlyResponseForGoGetMeta(ctx *Context) {
 		ctx.PlainText(http.StatusBadRequest, "invalid repository path")
 		return
 	}
-	ctx.PlainText(http.StatusOK, com.Expand(`<meta name="go-import" content="{GoGetImport} git {CloneLink}">`,
-		map[string]string{
-			"GoGetImport": ComposeGoGetImport(username, reponame),
-			"CloneLink":   repo_model.ComposeHTTPSCloneURL(username, reponame),
-		}))
+
+	ctx.PlainText(http.StatusOK, fmt.Sprintf(`<meta name="go-import" content="%s git %s">`,
+		ComposeGoGetImport(username, reponame),
+		repo_model.ComposeHTTPSCloneURL(username, reponame),
+	))
 }
 
 // RedirectToRepo redirect to a differently-named repository

modules/markup/html.go

@@ -21,9 +21,9 @@ import (
 	"code.gitea.io/gitea/modules/markup/common"
 	"code.gitea.io/gitea/modules/references"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/templates/vars"
 	"code.gitea.io/gitea/modules/util"
 
-	"github.com/unknwon/com"
 	"golang.org/x/net/html"
 	"golang.org/x/net/html/atom"
 	"mvdan.cc/xurls/v2"
@@ -838,7 +838,14 @@ func issueIndexPatternProcessor(ctx *RenderContext, node *html.Node) {
 		reftext := node.Data[ref.RefLocation.Start:ref.RefLocation.End]
 		if exttrack && !ref.IsPull {
 			ctx.Metas["index"] = ref.Issue
-			link = createLink(com.Expand(ctx.Metas["format"], ctx.Metas), reftext, "ref-issue ref-external-issue")
+
+			res, err := vars.Expand(ctx.Metas["format"], ctx.Metas)
+			if err != nil {
+				log.Error(err.Error())
+				return
+			}
+
+			link = createLink(res, reftext, "ref-issue ref-external-issue")
 		} else {
 			// Path determines the type of link that will be rendered. It's unknown at this point whether
 			// the linked item is actually a PR or an issue. Luckily it's of no real consequence because

modules/repository/init.go

@@ -22,10 +22,9 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/options"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/templates/vars"
 	"code.gitea.io/gitea/modules/util"
 	asymkey_service "code.gitea.io/gitea/services/asymkey"
-
-	"github.com/unknwon/com"
 )
 
 var (
@@ -250,8 +249,12 @@ func prepareRepoCommit(ctx context.Context, repo *repo_model.Repository, tmpDir,
 		"CloneURL.HTTPS": cloneLink.HTTPS,
 		"OwnerName":      repo.OwnerName,
 	}
+	res, err := vars.Expand(string(data), match)
+	if err != nil {
+		return fmt.Errorf("expand README.md: %v", err)
+	}
 	if err = os.WriteFile(filepath.Join(tmpDir, "README.md"),
-		[]byte(com.Expand(string(data), match)), 0o644); err != nil {
+		[]byte(res), 0o644); err != nil {
 		return fmt.Errorf("write README.md: %v", err)
 	}
 

modules/templates/vars/vars.go

@@ -0,0 +1,105 @@
+// 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 vars
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ErrWrongSyntax represents a syntax error within a template
+type ErrWrongSyntax struct {
+	Template string
+	Reason   string
+}
+
+func (err ErrWrongSyntax) Error() string {
+	return fmt.Sprintf("Wrong syntax found in %s: %s", err.Template, err.Reason)
+}
+
+// IsErrWrongSyntax returns true if the error is ErrWrongSyntax
+func IsErrWrongSyntax(err error) bool {
+	_, ok := err.(ErrWrongSyntax)
+	return ok
+}
+
+// ErrNoMatchedVar represents an error that no matched vars
+type ErrNoMatchedVar struct {
+	Template string
+	Var      string
+}
+
+func (err ErrNoMatchedVar) Error() string {
+	return fmt.Sprintf("No matched variable %s found for %s", err.Var, err.Template)
+}
+
+// IsErrNoMatchedVar returns true if the error is ErrNoMatchedVar
+func IsErrNoMatchedVar(err error) bool {
+	_, ok := err.(ErrNoMatchedVar)
+	return ok
+}
+
+// Expand replaces all variables like {var} to match
+func Expand(template string, match map[string]string, subs ...string) (string, error) {
+	var (
+		buf         strings.Builder
+		keyStartPos = -1
+	)
+	for i, c := range template {
+		switch {
+		case c == '{':
+			if keyStartPos > -1 {
+				return "", ErrWrongSyntax{
+					Template: template,
+					Reason:   "\"{\" is not allowed to occur again before closing the variable",
+				}
+			}
+			keyStartPos = i
+		case c == '}':
+			if keyStartPos == -1 {
+				return "", ErrWrongSyntax{
+					Template: template,
+					Reason:   "\"}\" can only occur after an opening \"{\"",
+				}
+			}
+			if i-keyStartPos <= 1 {
+				return "", ErrWrongSyntax{
+					Template: template,
+					Reason:   "the empty variable (\"{}\") is not allowed",
+				}
+			}
+
+			if len(match) == 0 {
+				return "", ErrNoMatchedVar{
+					Template: template,
+					Var:      template[keyStartPos+1 : i],
+				}
+			}
+
+			v, ok := match[template[keyStartPos+1:i]]
+			if !ok {
+				if len(subs) == 0 {
+					return "", ErrNoMatchedVar{
+						Template: template,
+						Var:      template[keyStartPos+1 : i],
+					}
+				}
+				v = subs[0]
+			}
+
+			if _, err := buf.WriteString(v); err != nil {
+				return "", err
+			}
+
+			keyStartPos = -1
+		case keyStartPos > -1:
+		default:
+			if _, err := buf.WriteRune(c); err != nil {
+				return "", err
+			}
+		}
+	}
+	return buf.String(), nil
+}

modules/templates/vars/vars_test.go

@@ -0,0 +1,70 @@
+// 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 vars
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestExpandVars(t *testing.T) {
+	kases := []struct {
+		template string
+		maps     map[string]string
+		expected string
+		fail     bool
+	}{
+		{
+			template: "{a}",
+			maps: map[string]string{
+				"a": "1",
+			},
+			expected: "1",
+		},
+		{
+			template: "expand {a}, {b} and {c}",
+			maps: map[string]string{
+				"a": "1",
+				"b": "2",
+				"c": "3",
+			},
+			expected: "expand 1, 2 and 3",
+		},
+		{
+			template: "中文内容 {一}, {二} 和 {三} 中文结尾",
+			maps: map[string]string{
+				"一": "11",
+				"二": "22",
+				"三": "33",
+			},
+			expected: "中文内容 11, 22 和 33 中文结尾",
+		},
+		{
+			template: "expand {{a}, {b} and {c}",
+			fail:     true,
+		},
+		{
+			template: "expand {}, {b} and {c}",
+			fail:     true,
+		},
+		{
+			template: "expand }, {b} and {c}",
+			fail:     true,
+		},
+	}
+
+	for _, kase := range kases {
+		t.Run(kase.template, func(t *testing.T) {
+			res, err := Expand(kase.template, kase.maps)
+			if kase.fail {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+			assert.EqualValues(t, kase.expected, res)
+		})
+	}
+}

routers/web/goget.go

@@ -7,15 +7,14 @@ package web
 import (
 	"net/http"
 	"net/url"
+	"os"
 	"path"
 	"strings"
 
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-
-	"github.com/unknwon/com"
 )
 
 func goGet(ctx *context.Context) {
@@ -67,21 +66,37 @@ func goGet(ctx *context.Context) {
 	}
 	ctx.RespHeader().Set("Content-Type", "text/html")
 	ctx.Status(http.StatusOK)
-	_, _ = ctx.Write([]byte(com.Expand(`<!doctype html>
+	res := os.Expand(`<!doctype html>
 <html>
 	<head>
-		<meta name="go-import" content="{GoGetImport} git {CloneLink}">
-		<meta name="go-source" content="{GoGetImport} _ {GoDocDirectory} {GoDocFile}">
+		<meta name="go-import" content="${GoGetImport} git ${CloneLink}">
+		<meta name="go-source" content="${GoGetImport} _ ${GoDocDirectory} ${GoDocFile}">
 	</head>
 	<body>
-		go get {Insecure}{GoGetImport}
+		go get ${Insecure}${GoGetImport}
 	</body>
 </html>
-`, map[string]string{
-		"GoGetImport":    context.ComposeGoGetImport(ownerName, trimmedRepoName),
-		"CloneLink":      repo_model.ComposeHTTPSCloneURL(ownerName, repoName),
-		"GoDocDirectory": prefix + "{/dir}",
-		"GoDocFile":      prefix + "{/dir}/{file}#L{line}",
-		"Insecure":       insecure,
-	})))
+`, func(key string) string {
+		switch key {
+		case "GoGetImport":
+			return context.ComposeGoGetImport(ownerName, trimmedRepoName)
+		case "CloneLink":
+			return repo_model.ComposeHTTPSCloneURL(ownerName, repoName)
+		case "GoDocDirectory":
+			return prefix + "{/dir}"
+		case "GoDocFile":
+			return prefix + "{/dir}/{file}#L{line}"
+		case "Insecure":
+			return insecure
+		default:
+			return `<!doctype html>
+			<html>
+				<body>
+					invalid import path
+				</body>
+			</html>
+			`
+		}
+	})
+	_, _ = ctx.Write([]byte(res))
 }

routers/web/repo/issue.go

@@ -35,6 +35,7 @@ import (
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
+	"code.gitea.io/gitea/modules/templates/vars"
 	"code.gitea.io/gitea/modules/upload"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/web"
@@ -43,8 +44,6 @@ import (
 	"code.gitea.io/gitea/services/forms"
 	issue_service "code.gitea.io/gitea/services/issue"
 	pull_service "code.gitea.io/gitea/services/pull"
-
-	"github.com/unknwon/com"
 )
 
 const (
@@ -1113,7 +1112,12 @@ func ViewIssue(ctx *context.Context) {
 			if extIssueUnit.ExternalTrackerConfig().ExternalTrackerStyle == markup.IssueNameStyleNumeric || extIssueUnit.ExternalTrackerConfig().ExternalTrackerStyle == "" {
 				metas := ctx.Repo.Repository.ComposeMetas()
 				metas["index"] = ctx.Params(":index")
-				ctx.Redirect(com.Expand(extIssueUnit.ExternalTrackerConfig().ExternalTrackerFormat, metas))
+				res, err := vars.Expand(extIssueUnit.ExternalTrackerConfig().ExternalTrackerFormat, metas)
+				if err != nil {
+					ctx.ServerError("Expand", fmt.Errorf("unable to expand template vars for issue url. issue: %s, err: %s", metas["index"], err.Error()))
+					return
+				}
+				ctx.Redirect(res)
 				return
 			}
 		} else if err != nil && !repo_model.IsErrUnitTypeNotExist(err) {