initial commits

httpaccept.go

@@ -0,0 +1,104 @@
+package httpaccept
+
+import (
+	"sourcecode.social/reiver/go-httpaccept/mediarange"
+
+	"strings"
+)
+
+// HTTPAccept represents the values of the Accept headers of an HTTP request.
+//
+// Note that an HTTP request can have multople Accept headers.
+type HTTPAccept struct {
+	mediaranges []mediarange.MediaRange
+}
+
+// Create creates an HTTPAccept.
+//
+// For example:
+//
+//	// Accept: application/activity+json
+//	accept := httpaccept.Create(
+//		mediarange.Create("application", "activity+json"), // application/activity+json
+//	)
+//
+//	// Accept: image/png,image/gif
+//	accept := httpaccept.Create(
+//		mediarange.Create("image", "png"), // image/png
+//		mediarange.Create("image", "gif"), // image/gif
+//	)
+func Create(mediaranges ...mediarange.MediaRange) HTTPAccept {
+	return HTTPAccept{
+		mediaranges:mediaranges,
+	}
+}
+
+// Negotiate figures out if there is an acceptable media-type, and if there is returns the "best" one.
+//
+// For example:
+//
+//	var accept httpaccept.HTTPAccept
+//	
+//	// ...
+//	
+//	contentType, err := accept.Negotiate("text/gemini", "text/html", "application/activity+json")
+func (receiver HTTPAccept) Negotiate(mediatypes ...string) (string, error) {
+
+	var temp []string
+
+	{
+		temp, mediatypes = mediatypes, nil
+
+		for _, mediatype := range temp {
+
+			a := strings.SplitN(mediatype, ";", 2)
+			if len(a) < 1 {
+				continue
+			}
+
+			mediatypes = append(mediatypes, a[0])
+		}
+	}
+
+	for _, mediarange := range receiver.mediaranges {
+
+		for _, mediatype := range mediatypes {
+
+			if mediarange.Match(mediatype) {
+				return mediatype, nil
+			}
+		}
+	}
+
+	return "", internalNotAcceptable{temp}
+}
+
+// String returns the serialized HTTP Accept header.
+//
+// For example:
+//
+//	// "Accept: text/html,application/xhtml+xml\r\n"
+//	s := httpaccept.Create(mediarange.Create("text", "html"), mediarange.Create("application","xhtml+xml")).String()
+func (receiver HTTPAccept) String() string {
+	var mediaranges []mediarange.MediaRange = receiver.mediaranges
+
+	if len(mediaranges) < 1 {
+		return ""
+	}
+
+	var buffer strings.Builder
+	{
+		buffer.WriteString("Accept: ")
+		for i, mediarange := range receiver.mediaranges {
+
+			if 0 != i {
+				buffer.WriteRune(',')
+			}
+			buffer.WriteString(mediarange.String())
+		}
+		buffer.WriteString("\r\n")
+
+	}
+
+	return buffer.String()
+}

httpaccept_string_test.go

@@ -0,0 +1,61 @@
+package httpaccept_test
+
+import (
+	"sourcecode.social/reiver/go-httpaccept"
+	"sourcecode.social/reiver/go-httpaccept/mediarange"
+
+	"testing"
+)
+
+func TestHTTPAccept_String(t *testing.T) {
+
+	tests := []struct{
+		HTTPAccept httpaccept.HTTPAccept
+		Expected string
+	}{
+		{
+			HTTPAccept: httpaccept.Create(),
+			Expected: "",
+		},
+
+
+
+		{
+			HTTPAccept: httpaccept.Create(mediarange.Create("*", "*")),
+			Expected: "Accept: */*"+"\r\n",
+		},
+		{
+			HTTPAccept: httpaccept.Create(mediarange.Create("text", "html"), mediarange.Create("*", "*")),
+			Expected: "Accept: text/html,*/*"+"\r\n",
+		},
+		{
+			HTTPAccept: httpaccept.Create(mediarange.Create("text", "html"), mediarange.Create("application", "xhtml+xml"), mediarange.Create("*", "*")),
+			Expected: "Accept: text/html,application/xhtml+xml,*/*"+"\r\n",
+		},
+
+
+
+		{
+			HTTPAccept: httpaccept.Create(mediarange.Create("application", "activity+json")),
+			Expected: "Accept: application/activity+json"+"\r\n",
+		},
+		{
+			HTTPAccept: httpaccept.Create(mediarange.Create("application", "activity+json"), mediarange.Create("application", "json")),
+			Expected: "Accept: application/activity+json,application/json"+"\r\n",
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		actual := test.HTTPAccept.String()
+		expected := test.Expected
+
+		if expected != actual {
+			t.Errorf("For test #%d, the actual (serialized) stringer value is not what was expected.", testNumber)
+			t.Logf("HTTP-ACCEPT: %#v", test.HTTPAccept)
+			t.Logf("EXPECTED: %q", expected)
+			t.Logf("ACTUAL:   %q", actual)
+			continue
+		}
+	}
+}