Additional testing and backwards compatibility note.

Author: bigkevmcd

README.md

@@ -44,3 +44,13 @@ Content-Type: text/plain; charset=utf-8
 
 Hello, World!
 ```
+
+Backwards compatibility
+-----------------------
+
+If you need backwards compatibility with `CacheOptions` configuration, you can
+wrap it in a `Config` option with...
+
+```go
+http.Handle("/", cw.Cached(http.HandlerFunc(helloWorld), cw.Config(cw.CacheOptions{MaxAge: time.Hour * 24 * 13, NoTransform: true})))
+```

cache.go

@@ -98,6 +98,13 @@ func SharedMaxAge(d time.Duration) optionFunc {
 	}
 }
 
+// Config takes a CacheOptions value and replaces options.
+func Config(co CacheOptions) optionFunc {
+	return func(o *CacheOptions) {
+		*o = co
+	}
+}
+
 // These set the relevant pragmas in the response per
 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
 type CacheOptions struct {

cache_test.go

@@ -10,11 +10,15 @@ import (
 func TestCacheControl(t *testing.T) {
 	w := httptest.NewRecorder()
 	r, _ := http.NewRequest("POST", "http://example.com/foo", nil)
-	cached := Cached(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}), MaxAge(time.Hour*24*13), NoTransform())
+	handler := func(w http.ResponseWriter, r *http.Request) {}
+	opts := []optionFunc{MaxAge(time.Hour * 24 * 13), NoTransform()}
+	cached := Cached(http.HandlerFunc(handler), opts...)
+
 	cached.ServeHTTP(w, r)
 
-	if "no-transform, max-age=1123200" != w.Header().Get("Cache-Control") {
-		t.Fatalf("Cache-Control header: got %s, wanted 'no-transform, max-age=1123200'", w.Header().Get("Cache-Control"))
+	wanted := "no-transform, max-age=1123200"
+	if pragmas := w.Header().Get("Cache-Control"); pragmas != wanted {
+		t.Fatalf("Cache-Control header: got %s, wanted '%s'", pragmas, wanted)
 	}
 }
 
@@ -53,6 +57,7 @@ var cacheOptionFuncTests = []struct {
 	{MustRevalidate(), "must-revalidate"},
 	{ProxyRevalidate(), "proxy-revalidate"},
 	{SharedMaxAge(time.Hour * 13), "s-maxage=46800"},
+	{Config(CacheOptions{MaxAge: time.Hour * 24 * 13, NoTransform: true}), "no-transform, max-age=1123200"},
 }
 
 func TestOptionFuncs(t *testing.T) {
@@ -64,3 +69,18 @@ func TestOptionFuncs(t *testing.T) {
 		}
 	}
 }
+
+func TestMaintainsExistingCacheOptions(t *testing.T) {
+	w := httptest.NewRecorder()
+	r, _ := http.NewRequest("POST", "http://example.com/foo", nil)
+	handler := func(w http.ResponseWriter, r *http.Request) { w.Header().Set("Cache-Control", "must-revalidate") }
+	opts := []optionFunc{MaxAge(time.Hour * 24 * 13), NoTransform()}
+	cached := Cached(http.HandlerFunc(handler), opts...)
+
+	cached.ServeHTTP(w, r)
+
+	wanted := "must-revalidate"
+	if pragmas := w.Header().Get("Cache-Control"); pragmas != wanted {
+		t.Fatalf("Cache-Control header: got %s, wanted '%s'", pragmas, wanted)
+	}
+}