Gzip: Accept MIME types.

3 files changed, 122 insertions, 28 deletions

diff --git a/middleware/gzip/filter.go b/middleware/gzip/filter.go
index 517f88587..a945fed90 100644
--- a/middleware/gzip/filter.go
+++ b/middleware/gzip/filter.go
@@ -3,13 +3,14 @@ package gzip
 import (
 	"net/http"
 	"path"
+	"strings"
 
 	"github.com/mholt/caddy/middleware"
 )
 
 // Filter determines if a request should be gzipped.
 type Filter interface {
-	// ShouldCompress tells if compression gzip compression
+	// ShouldCompress tells if gzip compression
 	// should be done on the request.
 	ShouldCompress(*http.Request) bool
 }
@@ -20,24 +21,12 @@ type ExtFilter struct {
 	Exts Set
 }
 
-// textExts is a list of extensions for text related files.
-var textExts = []string{
-	".html", ".htm", ".css", ".json", ".php", ".js", ".txt", ".md", ".xml",
-}
-
 // extWildCard is the wildcard for extensions.
 const extWildCard = "*"
 
-// DefaultExtFilter creates a default ExtFilter with
-// file extensions for text types.
-func DefaultExtFilter() ExtFilter {
-	e := ExtFilter{make(Set)}
-	for _, ext := range textExts {
-		e.Exts.Add(ext)
-	}
-	return e
-}
-
+// ShouldCompress checks if the request file extension matches any
+// of the registered extensions. It returns true if the extension is
+// found and false otherwise.
 func (e ExtFilter) ShouldCompress(r *http.Request) bool {
 	ext := path.Ext(r.URL.Path)
 	return e.Exts.Contains(extWildCard) || e.Exts.Contains(ext)
@@ -50,7 +39,7 @@ type PathFilter struct {
 }
 
 // ShouldCompress checks if the request path matches any of the
-// registered paths to ignore. If returns false if an ignored path
+// registered paths to ignore. It returns false if an ignored path
 // is found and true otherwise.
 func (p PathFilter) ShouldCompress(r *http.Request) bool {
 	return !p.IgnoredPaths.ContainsFunc(func(value string) bool {
@@ -58,6 +47,39 @@ func (p PathFilter) ShouldCompress(r *http.Request) bool {
 	})
 }
 
+// MIMEFilter is Filter for request content types.
+type MIMEFilter struct {
+	// Types is the MIME types to accept.
+	Types Set
+}
+
+// defaultMIMETypes is the list of default MIME types to use.
+var defaultMIMETypes = []string{
+	"text/plain", "text/html", "text/css", "application/json", "application/javascript",
+	"text/x-markdown", "text/xml", "application/xml",
+}
+
+// DefaultMIMEFilter creates a MIMEFilter with default types.
+func DefaultMIMEFilter() MIMEFilter {
+	m := MIMEFilter{Types: make(Set)}
+	for _, mime := range defaultMIMETypes {
+		m.Types.Add(mime)
+	}
+	return m
+}
+
+// ShouldCompress checks if the content type of the request
+// matches any of the registered ones. It returns true if
+// found and false otherwise.
+func (m MIMEFilter) ShouldCompress(r *http.Request) bool {
+	return m.Types.Contains(r.Header.Get("Content-Type"))
+}
+
+func ValidMIME(mime string) bool {
+	s := strings.Split(mime, "/")
+	return len(s) == 2 && strings.TrimSpace(s[0]) != "" && strings.TrimSpace(s[1]) != ""
+}
+
 // Set stores distinct strings.
 type Set map[string]struct{}
 
diff --git a/middleware/gzip/filter_test.go b/middleware/gzip/filter_test.go
index 56d054cfe..c3664cdd7 100644
--- a/middleware/gzip/filter_test.go
+++ b/middleware/gzip/filter_test.go
@@ -47,13 +47,13 @@ func TestSet(t *testing.T) {
 }
 
 func TestExtFilter(t *testing.T) {
-	var filter Filter = DefaultExtFilter()
-	_ = filter.(ExtFilter)
-	for i, e := range textExts {
-		r := urlRequest("file" + e)
-		if !filter.ShouldCompress(r) {
-			t.Errorf("Test %v: Should be valid filter", i)
-		}
+	var filter Filter = ExtFilter{make(Set)}
+	for _, e := range []string{".txt", ".html", ".css", ".md"} {
+		filter.(ExtFilter).Exts.Add(e)
+	}
+	r := urlRequest("file.txt")
+	if !filter.ShouldCompress(r) {
+		t.Errorf("Should be valid filter")
 	}
 	var exts = []string{
 		".html", ".css", ".md",
@@ -100,6 +100,32 @@ func TestPathFilter(t *testing.T) {
 	}
 }
 
+func TestMIMEFilter(t *testing.T) {
+	var filter Filter = DefaultMIMEFilter()
+	_ = filter.(MIMEFilter)
+	var mimes = []string{
+		"text/html", "text/css", "application/json",
+	}
+	for i, m := range mimes {
+		r := urlRequest("file" + m)
+		r.Header.Set("Content-Type", m)
+		if !filter.ShouldCompress(r) {
+			t.Errorf("Test %v: Should be valid filter", i)
+		}
+	}
+	mimes = []string{
+		"image/jpeg", "image/png",
+	}
+	filter = DefaultMIMEFilter()
+	for i, m := range mimes {
+		r := urlRequest("file" + m)
+		r.Header.Set("Content-Type", m)
+		if filter.ShouldCompress(r) {
+			t.Errorf("Test %v: Should not be valid filter", i)
+		}
+	}
+}
+
 func urlRequest(url string) *http.Request {
 	r, _ := http.NewRequest("GET", url, nil)
 	return r
diff --git a/middleware/gzip/gzip_test.go b/middleware/gzip/gzip_test.go
index 7015a5b77..ae0e300c8 100644
--- a/middleware/gzip/gzip_test.go
+++ b/middleware/gzip/gzip_test.go
@@ -16,13 +16,20 @@ func TestGzipHandler(t *testing.T) {
 	for _, p := range badPaths {
 		pathFilter.IgnoredPaths.Add(p)
 	}
+	extFilter := ExtFilter{make(Set)}
+	for _, e := range []string{".txt", ".html", ".css", ".md"} {
+		extFilter.Exts.Add(e)
+	}
 	gz := Gzip{Configs: []Config{
-		Config{Filters: []Filter{DefaultExtFilter(), pathFilter}},
+		Config{Filters: []Filter{pathFilter, extFilter}},
 	}}
 
 	w := httptest.NewRecorder()
 	gz.Next = nextFunc(true)
-	for _, e := range textExts {
+	var exts = []string{
+		".html", ".css", ".md",
+	}
+	for _, e := range exts {
 		url := "/file" + e
 		r, err := http.NewRequest("GET", url, nil)
 		if err != nil {
@@ -38,7 +45,7 @@ func TestGzipHandler(t *testing.T) {
 	w = httptest.NewRecorder()
 	gz.Next = nextFunc(false)
 	for _, p := range badPaths {
-		for _, e := range textExts {
+		for _, e := range exts {
 			url := p + "/file" + e
 			r, err := http.NewRequest("GET", url, nil)
 			if err != nil {
@@ -54,7 +61,7 @@ func TestGzipHandler(t *testing.T) {
 
 	w = httptest.NewRecorder()
 	gz.Next = nextFunc(false)
-	exts := []string{
+	exts = []string{
 		".htm1", ".abc", ".mdx",
 	}
 	for _, e := range exts {
@@ -70,6 +77,45 @@ func TestGzipHandler(t *testing.T) {
 		}
 	}
 
+	gz.Configs[0].Filters[1] = DefaultMIMEFilter()
+	w = httptest.NewRecorder()
+	gz.Next = nextFunc(true)
+	var mimes = []string{
+		"text/html", "text/css", "application/json",
+	}
+	for _, m := range mimes {
+		url := "/file"
+		r, err := http.NewRequest("GET", url, nil)
+		if err != nil {
+			t.Error(err)
+		}
+		r.Header.Set("Content-Type", m)
+		r.Header.Set("Accept-Encoding", "gzip")
+		_, err = gz.ServeHTTP(w, r)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
+	w = httptest.NewRecorder()
+	gz.Next = nextFunc(false)
+	mimes = []string{
+		"image/jpeg", "image/png",
+	}
+	for _, m := range mimes {
+		url := "/file"
+		r, err := http.NewRequest("GET", url, nil)
+		if err != nil {
+			t.Error(err)
+		}
+		r.Header.Set("Content-Type", m)
+		r.Header.Set("Accept-Encoding", "gzip")
+		_, err = gz.ServeHTTP(w, r)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+
 }
 
 func nextFunc(shouldGzip bool) middleware.Handler {