fileserver: Share template logic for both templates and file_server browse (#4093)

Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>

modules/caddyhttp/fileserver/browse.go

@@ -17,14 +17,16 @@ package fileserver
 import (
 	"bytes"
 	"encoding/json"
-	"html/template"
+	"fmt"
 	"net/http"
 	"os"
 	"path"
 	"strings"
+	"text/template"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp/templates"
 	"go.uber.org/zap"
 )
 
@@ -82,7 +84,26 @@ func (fsrv *FileServer) serveBrowse(root, dirPath string, w http.ResponseWriter,
 		}
 		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	} else {
-		if buf, err = fsrv.browseWriteHTML(listing); err != nil {
+		var fs http.FileSystem
+		if fsrv.Root != "" {
+			fs = http.Dir(repl.ReplaceAll(fsrv.Root, "."))
+		}
+
+		var tplCtx = &templateContext{
+			TemplateContext: templates.TemplateContext{
+				Root:       fs,
+				Req:        r,
+				RespHeader: templates.WrappedHeader{Header: w.Header()},
+			},
+			browseTemplateContext: listing,
+		}
+
+		err = fsrv.makeBrowseTemplate(tplCtx)
+		if err != nil {
+			return fmt.Errorf("parsing browse template: %v", err)
+		}
+
+		if buf, err = fsrv.browseWriteHTML(tplCtx); err != nil {
 			return caddyhttp.Error(http.StatusInternalServerError, err)
 		}
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
@@ -93,10 +114,10 @@ func (fsrv *FileServer) serveBrowse(root, dirPath string, w http.ResponseWriter,
 	return nil
 }
 
-func (fsrv *FileServer) loadDirectoryContents(dir *os.File, root, urlPath string, repl *caddy.Replacer) (browseListing, error) {
+func (fsrv *FileServer) loadDirectoryContents(dir *os.File, root, urlPath string, repl *caddy.Replacer) (browseTemplateContext, error) {
 	files, err := dir.Readdir(-1)
 	if err != nil {
-		return browseListing{}, err
+		return browseTemplateContext{}, err
 	}
 
 	// user can presumably browse "up" to parent folder if path is longer than "/"
@@ -107,7 +128,7 @@ func (fsrv *FileServer) loadDirectoryContents(dir *os.File, root, urlPath string
 
 // browseApplyQueryParams applies query parameters to the listing.
 // It mutates the listing and may set cookies.
-func (fsrv *FileServer) browseApplyQueryParams(w http.ResponseWriter, r *http.Request, listing *browseListing) {
+func (fsrv *FileServer) browseApplyQueryParams(w http.ResponseWriter, r *http.Request, listing *browseTemplateContext) {
 	sortParam := r.URL.Query().Get("sort")
 	orderParam := r.URL.Query().Get("order")
 	limitParam := r.URL.Query().Get("limit")
@@ -139,17 +160,41 @@ func (fsrv *FileServer) browseApplyQueryParams(w http.ResponseWriter, r *http.Re
 	listing.applySortAndLimit(sortParam, orderParam, limitParam, offsetParam)
 }
 
-func (fsrv *FileServer) browseWriteJSON(listing browseListing) (*bytes.Buffer, error) {
+// makeBrowseTemplate creates the template to be used for directory listings.
+func (fsrv *FileServer) makeBrowseTemplate(tplCtx *templateContext) error {
+	var tpl *template.Template
+	var err error
+
+	if fsrv.Browse.TemplateFile != "" {
+		tpl = tplCtx.NewTemplate(path.Base(fsrv.Browse.TemplateFile))
+		tpl, err = tpl.ParseFiles(fsrv.Browse.TemplateFile)
+		if err != nil {
+			return fmt.Errorf("parsing browse template file: %v", err)
+		}
+	} else {
+		tpl = tplCtx.NewTemplate("default_listing")
+		tpl, err = tpl.Parse(defaultBrowseTemplate)
+		if err != nil {
+			return fmt.Errorf("parsing default browse template: %v", err)
+		}
+	}
+
+	fsrv.Browse.template = tpl
+
+	return nil
+}
+
+func (fsrv *FileServer) browseWriteJSON(listing browseTemplateContext) (*bytes.Buffer, error) {
 	buf := bufPool.Get().(*bytes.Buffer)
+	defer bufPool.Put(buf)
 	err := json.NewEncoder(buf).Encode(listing.Items)
-	bufPool.Put(buf)
 	return buf, err
 }
 
-func (fsrv *FileServer) browseWriteHTML(listing browseListing) (*bytes.Buffer, error) {
+func (fsrv *FileServer) browseWriteHTML(tplCtx *templateContext) (*bytes.Buffer, error) {
 	buf := bufPool.Get().(*bytes.Buffer)
-	err := fsrv.Browse.template.Execute(buf, listing)
+	defer bufPool.Put(buf)
-	bufPool.Put(buf)
+	err := fsrv.Browse.template.Execute(buf, tplCtx)
 	return buf, err
 }
 
@@ -171,3 +216,11 @@ func isSymlinkTargetDir(f os.FileInfo, root, urlPath string) bool {
 	}
 	return targetInfo.IsDir()
 }
+
+// templateContext powers the context used when evaluating the browse template.
+// It combines browse-specific features with the standard templates handler
+// features.
+type templateContext struct {
+	templates.TemplateContext
+	browseTemplateContext
+}

modules/caddyhttp/fileserver/browse_test.go

@@ -1,16 +1,27 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package fileserver
 
 import (
-	"html/template"
 	"testing"
-
+	"text/template"
-	"github.com/caddyserver/caddy/v2"
 )
 
 func BenchmarkBrowseWriteJSON(b *testing.B) {
 	fsrv := new(FileServer)
-	fsrv.Provision(caddy.Context{})
+	listing := browseTemplateContext{
-	listing := browseListing{
 		Name:     "test",
 		Path:     "test",
 		CanGoUp:  false,
@@ -30,12 +41,11 @@ func BenchmarkBrowseWriteJSON(b *testing.B) {
 
 func BenchmarkBrowseWriteHTML(b *testing.B) {
 	fsrv := new(FileServer)
-	fsrv.Provision(caddy.Context{})
 	fsrv.Browse = &Browse{
 		TemplateFile: "",
 		template:     template.New("test"),
 	}
-	listing := browseListing{
+	listing := browseTemplateContext{
 		Name:     "test",
 		Path:     "test",
 		CanGoUp:  false,
@@ -46,9 +56,13 @@ func BenchmarkBrowseWriteHTML(b *testing.B) {
 		Order:    "",
 		Limit:    42,
 	}
+	tplCtx := &templateContext{
+		browseTemplateContext: listing,
+	}
+	fsrv.makeBrowseTemplate(tplCtx)
 	b.ResetTimer()
 
 	for n := 0; n < b.N; n++ {
-		fsrv.browseWriteHTML(listing)
+		fsrv.browseWriteHTML(tplCtx)
 	}
 }

modules/caddyhttp/fileserver/browsetplcontext.go

@@ -27,7 +27,7 @@ import (
 	"github.com/dustin/go-humanize"
 )
 
-func (fsrv *FileServer) directoryListing(files []os.FileInfo, canGoUp bool, root, urlPath string, repl *caddy.Replacer) browseListing {
+func (fsrv *FileServer) directoryListing(files []os.FileInfo, canGoUp bool, root, urlPath string, repl *caddy.Replacer) browseTemplateContext {
 	filesToHide := fsrv.transformHidePaths(repl)
 
 	var dirCount, fileCount int
@@ -62,7 +62,7 @@ func (fsrv *FileServer) directoryListing(files []os.FileInfo, canGoUp bool, root
 		})
 	}
 
-	return browseListing{
+	return browseTemplateContext{
 		Name:     path.Base(urlPath),
 		Path:     urlPath,
 		CanGoUp:  canGoUp,
@@ -72,7 +72,8 @@ func (fsrv *FileServer) directoryListing(files []os.FileInfo, canGoUp bool, root
 	}
 }
 
-type browseListing struct {
+// browseTemplateContext provides the template context for directory listings.
+type browseTemplateContext struct {
 	// The name of the directory (the last element of the path).
 	Name string `json:"name"`
 
@@ -106,7 +107,7 @@ type browseListing struct {
 
 // Breadcrumbs returns l.Path where every element maps
 // the link to the text to display.
-func (l browseListing) Breadcrumbs() []crumb {
+func (l browseTemplateContext) Breadcrumbs() []crumb {
 	if len(l.Path) == 0 {
 		return []crumb{}
 	}
@@ -130,7 +131,7 @@ func (l browseListing) Breadcrumbs() []crumb {
 	return result
 }
 
-func (l *browseListing) applySortAndLimit(sortParam, orderParam, limitParam string, offsetParam string) {
+func (l *browseTemplateContext) applySortAndLimit(sortParam, orderParam, limitParam string, offsetParam string) {
 	l.Sort = sortParam
 	l.Order = orderParam
 
@@ -207,10 +208,12 @@ func (fi fileInfo) HumanModTime(format string) string {
 	return fi.ModTime.Format(format)
 }
 
-type byName browseListing
+type (
-type byNameDirFirst browseListing
+	byName         browseTemplateContext
-type bySize browseListing
+	byNameDirFirst browseTemplateContext
-type byTime browseListing
+	bySize         browseTemplateContext
+	byTime         browseTemplateContext
+)
 
 func (l byName) Len() int      { return len(l.Items) }
 func (l byName) Swap(i, j int) { l.Items[i], l.Items[j] = l.Items[j], l.Items[i] }

modules/caddyhttp/fileserver/browsetplcontext_test.go

@@ -1,3 +1,17 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package fileserver
 
 import (
@@ -25,7 +39,7 @@ func TestBreadcrumbs(t *testing.T) {
 	}
 
 	for _, d := range testdata {
-		l := browseListing{Path: d.path}
+		l := browseTemplateContext{Path: d.path}
 		actual := l.Breadcrumbs()
 		if len(actual) != len(d.expected) {
 			t.Errorf("wrong size output, got %d elements but expected %d", len(actual), len(d.expected))

modules/caddyhttp/fileserver/staticfiles.go

@@ -17,7 +17,6 @@ package fileserver
 import (
 	"bytes"
 	"fmt"
-	"html/template"
 	weakrand "math/rand"
 	"mime"
 	"net/http"
@@ -118,23 +117,6 @@ func (fsrv *FileServer) Provision(ctx caddy.Context) error {
 		fsrv.IndexNames = defaultIndexNames
 	}
 
-	if fsrv.Browse != nil {
-		var tpl *template.Template
-		var err error
-		if fsrv.Browse.TemplateFile != "" {
-			tpl, err = template.ParseFiles(fsrv.Browse.TemplateFile)
-			if err != nil {
-				return fmt.Errorf("parsing browse template file: %v", err)
-			}
-		} else {
-			tpl, err = template.New("default_listing").Parse(defaultBrowseTemplate)
-			if err != nil {
-				return fmt.Errorf("parsing default browse template: %v", err)
-			}
-		}
-		fsrv.Browse.template = tpl
-	}
-
 	// for hide paths that are static (i.e. no placeholders), we can transform them into
 	// absolute paths before the server starts for very slight performance improvement
 	for i, h := range fsrv.Hide {

modules/caddyhttp/templates/templates.go

@@ -37,7 +37,7 @@ func init() {
 //
 // [All Sprig functions](https://masterminds.github.io/sprig/) are supported.
 //
-// In addition to the standard functions and Sprig functions, Caddy adds
+// In addition to the standard functions and the Sprig library, Caddy adds
 // extra functions and data that are available to a template:
 //
 // ##### `.Args`
@@ -303,10 +303,10 @@ func (t *Templates) executeTemplate(rr caddyhttp.ResponseRecorder, r *http.Reque
 		fs = http.Dir(repl.ReplaceAll(t.FileRoot, "."))
 	}
 
-	ctx := &templateContext{
+	ctx := &TemplateContext{
 		Root:       fs,
 		Req:        r,
-		RespHeader: tplWrappedHeader{rr.Header()},
+		RespHeader: WrappedHeader{rr.Header()},
 		config:     t,
 	}
 

modules/caddyhttp/templates/tplcontext.go

@@ -38,19 +38,49 @@ import (
 	gmhtml "github.com/yuin/goldmark/renderer/html"
 )
 
-// templateContext is the templateContext with which HTTP templates are executed.
+// TemplateContext is the TemplateContext with which HTTP templates are executed.
-type templateContext struct {
+type TemplateContext struct {
 	Root       http.FileSystem
 	Req        *http.Request
 	Args       []interface{} // defined by arguments to funcInclude
-	RespHeader tplWrappedHeader
+	RespHeader WrappedHeader
 
 	config *Templates
 }
 
+// NewTemplate returns a new template intended to be evaluated with this
+// context, as it is initialized with configuration from this context.
+func (c TemplateContext) NewTemplate(tplName string) *template.Template {
+	tpl := template.New(tplName)
+
+	// customize delimiters, if applicable
+	if c.config != nil && len(c.config.Delimiters) == 2 {
+		tpl.Delims(c.config.Delimiters[0], c.config.Delimiters[1])
+	}
+
+	// add sprig library
+	tpl.Funcs(sprigFuncMap)
+
+	// add our own library
+	tpl.Funcs(template.FuncMap{
+		"include":          c.funcInclude,
+		"httpInclude":      c.funcHTTPInclude,
+		"stripHTML":        c.funcStripHTML,
+		"markdown":         c.funcMarkdown,
+		"splitFrontMatter": c.funcSplitFrontMatter,
+		"listFiles":        c.funcListFiles,
+		"env":              c.funcEnv,
+		"placeholder":      c.funcPlaceholder,
+		"fileExists":       c.funcFileExists,
+		"httpError":        c.funcHTTPError,
+	})
+
+	return tpl
+}
+
 // OriginalReq returns the original, unmodified, un-rewritten request as
 // it originally came in over the wire.
-func (c templateContext) OriginalReq() http.Request {
+func (c TemplateContext) OriginalReq() http.Request {
 	or, _ := c.Req.Context().Value(caddyhttp.OriginalRequestCtxKey).(http.Request)
 	return or
 }
@@ -59,7 +89,7 @@ func (c templateContext) OriginalReq() http.Request {
 // Note that included files are NOT escaped, so you should only include
 // trusted files. If it is not trusted, be sure to use escaping functions
 // in your template.
-func (c templateContext) funcInclude(filename string, args ...interface{}) (string, error) {
+func (c TemplateContext) funcInclude(filename string, args ...interface{}) (string, error) {
 	if c.Root == nil {
 		return "", fmt.Errorf("root file system not specified")
 	}
@@ -93,7 +123,7 @@ func (c templateContext) funcInclude(filename string, args ...interface{}) (stri
 // to the given URI on the same server. Note that included bodies
 // are NOT escaped, so you should only include trusted resources.
 // If it is not trusted, be sure to use escaping functions yourself.
-func (c templateContext) funcHTTPInclude(uri string) (string, error) {
+func (c TemplateContext) funcHTTPInclude(uri string) (string, error) {
 	// prevent virtual request loops by counting how many levels
 	// deep we are; and if we get too deep, return an error
 	recursionCount := 1
@@ -137,26 +167,8 @@ func (c templateContext) funcHTTPInclude(uri string) (string, error) {
 	return buf.String(), nil
 }
 
-func (c templateContext) executeTemplateInBuffer(tplName string, buf *bytes.Buffer) error {
+func (c TemplateContext) executeTemplateInBuffer(tplName string, buf *bytes.Buffer) error {
-	tpl := template.New(tplName)
+	tpl := c.NewTemplate(tplName)
-	if len(c.config.Delimiters) == 2 {
-		tpl.Delims(c.config.Delimiters[0], c.config.Delimiters[1])
-	}
-
-	tpl.Funcs(sprigFuncMap)
-
-	tpl.Funcs(template.FuncMap{
-		"include":          c.funcInclude,
-		"httpInclude":      c.funcHTTPInclude,
-		"stripHTML":        c.funcStripHTML,
-		"markdown":         c.funcMarkdown,
-		"splitFrontMatter": c.funcSplitFrontMatter,
-		"listFiles":        c.funcListFiles,
-		"env":              c.funcEnv,
-		"placeholder":      c.funcPlaceholder,
-		"fileExists":       c.funcFileExists,
-		"httpError":        c.funcHTTPError,
-	})
 
 	parsedTpl, err := tpl.Parse(buf.String())
 	if err != nil {
@@ -168,18 +180,18 @@ func (c templateContext) executeTemplateInBuffer(tplName string, buf *bytes.Buff
 	return parsedTpl.Execute(buf, c)
 }
 
-func (c templateContext) funcPlaceholder(name string) string {
+func (c TemplateContext) funcPlaceholder(name string) string {
 	repl := c.Req.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
 	value, _ := repl.GetString(name)
 	return value
 }
 
-func (templateContext) funcEnv(varName string) string {
+func (TemplateContext) funcEnv(varName string) string {
 	return os.Getenv(varName)
 }
 
 // Cookie gets the value of a cookie with name name.
-func (c templateContext) Cookie(name string) string {
+func (c TemplateContext) Cookie(name string) string {
 	cookies := c.Req.Cookies()
 	for _, cookie := range cookies {
 		if cookie.Name == name {
@@ -190,7 +202,7 @@ func (c templateContext) Cookie(name string) string {
 }
 
 // RemoteIP gets the IP address of the client making the request.
-func (c templateContext) RemoteIP() string {
+func (c TemplateContext) RemoteIP() string {
 	ip, _, err := net.SplitHostPort(c.Req.RemoteAddr)
 	if err != nil {
 		return c.Req.RemoteAddr
@@ -200,7 +212,7 @@ func (c templateContext) RemoteIP() string {
 
 // Host returns the hostname portion of the Host header
 // from the HTTP request.
-func (c templateContext) Host() (string, error) {
+func (c TemplateContext) Host() (string, error) {
 	host, _, err := net.SplitHostPort(c.Req.Host)
 	if err != nil {
 		if !strings.Contains(c.Req.Host, ":") {
@@ -214,7 +226,7 @@ func (c templateContext) Host() (string, error) {
 
 // funcStripHTML returns s without HTML tags. It is fairly naive
 // but works with most valid HTML inputs.
-func (templateContext) funcStripHTML(s string) string {
+func (TemplateContext) funcStripHTML(s string) string {
 	var buf bytes.Buffer
 	var inTag, inQuotes bool
 	var tagStart int
@@ -247,7 +259,7 @@ func (templateContext) funcStripHTML(s string) string {
 
 // funcMarkdown renders the markdown body as HTML. The resulting
 // HTML is NOT escaped so that it can be rendered as HTML.
-func (templateContext) funcMarkdown(input interface{}) (string, error) {
+func (TemplateContext) funcMarkdown(input interface{}) (string, error) {
 	inputStr := toString(input)
 
 	md := goldmark.New(
@@ -283,7 +295,7 @@ func (templateContext) funcMarkdown(input interface{}) (string, error) {
 // splitFrontMatter parses front matter out from the beginning of input,
 // and returns the separated key-value pairs and the body/content. input
 // must be a "stringy" value.
-func (templateContext) funcSplitFrontMatter(input interface{}) (parsedMarkdownDoc, error) {
+func (TemplateContext) funcSplitFrontMatter(input interface{}) (parsedMarkdownDoc, error) {
 	meta, body, err := extractFrontMatter(toString(input))
 	if err != nil {
 		return parsedMarkdownDoc{}, err
@@ -293,7 +305,7 @@ func (templateContext) funcSplitFrontMatter(input interface{}) (parsedMarkdownDo
 
 // funcListFiles reads and returns a slice of names from the given
 // directory relative to the root of c.
-func (c templateContext) funcListFiles(name string) ([]string, error) {
+func (c TemplateContext) funcListFiles(name string) ([]string, error) {
 	if c.Root == nil {
 		return nil, fmt.Errorf("root file system not specified")
 	}
@@ -326,7 +338,7 @@ func (c templateContext) funcListFiles(name string) ([]string, error) {
 }
 
 // funcFileExists returns true if filename can be opened successfully.
-func (c templateContext) funcFileExists(filename string) (bool, error) {
+func (c TemplateContext) funcFileExists(filename string) (bool, error) {
 	if c.Root == nil {
 		return false, fmt.Errorf("root file system not specified")
 	}
@@ -339,21 +351,21 @@ func (c templateContext) funcFileExists(filename string) (bool, error) {
 }
 
 // funcHTTPError returns a structured HTTP handler error. EXPERIMENTAL.
-// TODO: Requires https://github.com/golang/go/issues/34201 to be fixed.
+// TODO: Requires https://github.com/golang/go/issues/34201 to be fixed (Go 1.17).
 // Example usage might be: `{{if not (fileExists $includeFile)}}{{httpError 404}}{{end}}`
-func (c templateContext) funcHTTPError(statusCode int) (bool, error) {
+func (c TemplateContext) funcHTTPError(statusCode int) (bool, error) {
 	return false, caddyhttp.Error(statusCode, nil)
 }
 
-// tplWrappedHeader wraps niladic functions so that they
+// WrappedHeader wraps niladic functions so that they
 // can be used in templates. (Template functions must
 // return a value.)
-type tplWrappedHeader struct{ http.Header }
+type WrappedHeader struct{ http.Header }
 
 // Add adds a header field value, appending val to
 // existing values for that field. It returns an
 // empty string.
-func (h tplWrappedHeader) Add(field, val string) string {
+func (h WrappedHeader) Add(field, val string) string {
 	h.Header.Add(field, val)
 	return ""
 }
@@ -361,13 +373,13 @@ func (h tplWrappedHeader) Add(field, val string) string {
 // Set sets a header field value, overwriting any
 // other values for that field. It returns an
 // empty string.
-func (h tplWrappedHeader) Set(field, val string) string {
+func (h WrappedHeader) Set(field, val string) string {
 	h.Header.Set(field, val)
 	return ""
 }
 
 // Del deletes a header field. It returns an empty string.
-func (h tplWrappedHeader) Del(field string) string {
+func (h WrappedHeader) Del(field string) string {
 	h.Header.Del(field)
 	return ""
 }

modules/caddyhttp/templates/tplcontext_test.go

@@ -12,20 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Copyright 2015 Light Code Labs, LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
 package templates
 
 import (
@@ -357,7 +343,7 @@ title = "Welcome"
 
 }
 
-func getContextOrFail(t *testing.T) templateContext {
+func getContextOrFail(t *testing.T) TemplateContext {
 	context, err := initTestContext()
 	if err != nil {
 		t.Fatalf("failed to prepare test context: %v", err)
@@ -365,15 +351,15 @@ func getContextOrFail(t *testing.T) templateContext {
 	return context
 }
 
-func initTestContext() (templateContext, error) {
+func initTestContext() (TemplateContext, error) {
 	body := bytes.NewBufferString("request body")
 	request, err := http.NewRequest("GET", "https://example.com/foo/bar", body)
 	if err != nil {
-		return templateContext{}, err
+		return TemplateContext{}, err
 	}
-	return templateContext{
+	return TemplateContext{
 		Root:       http.Dir(os.TempDir()),
 		Req:        request,
-		RespHeader: tplWrappedHeader{make(http.Header)},
+		RespHeader: WrappedHeader{make(http.Header)},
 	}, nil
 }