Add tests for HTTP content encoding negotiation.

src/http_test.go

@@ -0,0 +1,39 @@
+package git_pages
+
+import "testing"
+
+func TestHttpContentEncodingNegotiation(t *testing.T) {
+	check := func(available []string, requested string, expected string) {
+		parsed := ParseAcceptEncodingHeader(requested)
+		negotiated := parsed.Negotiate(available...)
+		if negotiated != expected {
+			t.Errorf("accept %q, offer %q: expect %q, got %q",
+				requested, available, expected, negotiated)
+		}
+	}
+
+	// quality sorting
+	check([]string{"zstd", "identity"}, "zstd;q=1.0, identity;q=0.5", "zstd")
+	check([]string{"zstd", "identity"}, "zstd;q=1.0, identity;q=1.0", "zstd")
+	check([]string{"zstd", "identity"}, "zstd;q=0.5, identity;q=1.0", "identity")
+
+	// implicit identity
+	check([]string{"zstd", "identity"}, "", "identity")
+	check([]string{"zstd", "identity"}, "zstd;q=0", "identity")
+	check([]string{"zstd", "identity"}, "compress;q=0", "identity")
+
+	// wildcard fallback
+	check([]string{"zstd", "identity"}, "*", "zstd")
+	check([]string{"zstd", "identity"}, "identity;q=1, *;q=0", "identity")
+	check([]string{"zstd", "identity"}, "*;q=0, identity;q=1", "identity")
+
+	// negotiation failure
+	check([]string{"zstd", "identity"}, "*;q=0", "")
+	check([]string{"zstd", "identity"}, "identity;q=0", "")
+	check([]string{"zstd", "identity"}, "gzip;q=1.0, *;q=0", "")
+
+	// parser lenience
+	check([]string{"zstd", "identity"}, "zstd;q= 1.0", "identity")
+	check([]string{"zstd", "identity"}, "zstd;q=1.0000", "identity")
+	check([]string{"zstd", "identity"}, " zstd ; q=1.0, identity  ;  q=0.5  , *;q=0 ", "zstd")
+}