From 8f702e41bec013f9d7d5fca24de0eba71a094bf6 Mon Sep 17 00:00:00 2001
From: ICHINOSE Shogo <shogo82148@gmail.com>
Date: Tue, 6 Feb 2024 16:14:05 +0900
Subject: [PATCH] check Content-Encoding header value

---
 ridgenative.go      |   8 ++-
 ridgenative_test.go | 136 +++++++++++++++++++++++++++++++++++++-------
 2 files changed, 123 insertions(+), 21 deletions(-)

diff --git a/ridgenative.go b/ridgenative.go
index ca4bb9f..2cb5fce 100644
--- a/ridgenative.go
+++ b/ridgenative.go
@@ -360,7 +360,13 @@ func (rw *responseWriter) detectContentType() {
 }
 
 // assume text/*, application/json, application/javascript, application/xml, */*+json, */*+xml as text
-func isBinary(contentType string) bool {
+func isBinary(headers http.Header) bool {
+	contentEncoding := headers.Values("Content-Encoding")
+	if len(contentEncoding) > 0 {
+		return true
+	}
+
+	contentType := headers.Get("Content-Type")
 	i := strings.Index(contentType, ";")
 	if i == -1 {
 		i = len(contentType)
diff --git a/ridgenative_test.go b/ridgenative_test.go
index abacbb4..e59dd19 100644
--- a/ridgenative_test.go
+++ b/ridgenative_test.go
@@ -952,31 +952,127 @@ func TestLambdaHandlerStreaming(t *testing.T) {
 
 func TestIsBinary(t *testing.T) {
 	tests := []struct {
-		contentType string
-		want        bool
+		header http.Header
+		want   bool
 	}{
-		{"text/html", false},
-		{"text/plain", false},
-		{"text/xml", false},
-		{"application/json", false},
-		{"application/javascript", false},
-		{"application/yaml", false},
-		{"application/xml", false},
-		{"application/vnd.foo+json", false},
-		{"application/vnd.foo+yaml", false},
-		{"application/vnd.foo+xml", false},
-		{"application/vnd.foo+xml ; charset=utf8", false},
-		{"application/octet-stream", true},
-		{"image/jpeg", true},
-		{"audio/mpeg", true},
-		{"unknown-content-type", true},
-		{"", true},
+		// text/html but encoded as gzip
+		{
+			header: http.Header{
+				"Content-Type":     []string{"text/html; charset=utf-8"},
+				"Content-Encoding": []string{"gzip"},
+			},
+			want: true,
+		},
+
+		// text/*
+		{
+			header: http.Header{
+				"Content-Type": []string{"text/html"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"text/plain"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"text/xml"},
+			},
+			want: false,
+		},
+
+		// data formats that are encoded as text
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/json"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/javascript"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/yaml"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/xml"},
+			},
+			want: false,
+		},
+
+		// custom media types that are encoded as text
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/foo+json"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/foo+yaml"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/foo+xml"},
+			},
+			want: false,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/foo+xml ; charset=utf8"},
+			},
+			want: false,
+		},
+
+		// common binary formats
+		{
+			header: http.Header{
+				"Content-Type": []string{"application/octet-stream"},
+			},
+			want: true,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"image/jpeg"},
+			},
+			want: true,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"audio/mpeg"},
+			},
+			want: true,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{"unknown-content-type"},
+			},
+			want: true,
+		},
+		{
+			header: http.Header{
+				"Content-Type": []string{""},
+			},
+			want: true,
+		},
 	}
 
 	for _, tt := range tests {
-		got := isBinary(tt.contentType)
+		got := isBinary(tt.header)
 		if got != tt.want {
-			t.Errorf("isBinary(%q) = %v, want %v", tt.contentType, got, tt.want)
+			t.Errorf("isBinary(%v) = %v, want %v", tt.header, got, tt.want)
 		}
 	}
 }