refactor: add unit test for MP3 serving

filesystem_test.go

@@ -2,6 +2,9 @@ package gemini
 
 import (
 	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
 	"io/ioutil"
 	"net/url"
 	"testing"
@@ -104,3 +107,56 @@ func TestFileSystemHandler(t *testing.T) {
 		})
 	}
 }
+
+func TestFileSystemBinaryHandling(t *testing.T) {
+	var tests = []struct {
+		name           string
+		url            string
+		expectedHeader Header
+		expectedHash   string
+	}{
+		{
+			name: "mp3 files are served as expected",
+			url:  "cordova.mp3",
+			expectedHeader: Header{
+				Code: CodeSuccess,
+				Meta: "audio/mpeg",
+			},
+			expectedHash: "9f3bd09333627c218b3b0af371d9c7f4c6ac6a8b1c60b9e9aba0ca68c602e511",
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			dir := Dir("tests")
+			h := FileSystemHandler(dir)
+			u, err := url.Parse(tt.url)
+			if err != nil {
+				t.Fatalf("failed to parse URL %q", tt.url)
+			}
+			r := &Request{
+				Context: context.Background(),
+				URL:     u,
+			}
+			resp, err := Record(r, h)
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if tt.expectedHeader.Code != resp.Header.Code {
+				t.Errorf("expected header code %v, got %v", tt.expectedHeader.Code, resp.Header.Code)
+			}
+			if tt.expectedHeader.Meta != resp.Header.Meta {
+				t.Errorf("expected header meta %q, got %q", tt.expectedHeader.Meta, resp.Header.Meta)
+			}
+			hash := sha256.New()
+			_, err = io.Copy(hash, resp.Body)
+			if err != nil {
+				t.Fatalf("unexpected error reading body: %v", err)
+			}
+			actualHash := hex.EncodeToString(hash.Sum(nil))
+			if tt.expectedHash != actualHash {
+				t.Errorf("expected\n%v\nactual\n%v", tt.expectedHash, string(actualHash))
+			}
+		})
+	}
+}