Support Accept-Encoding header weights with Compress middleware

pkg/middlewares/compress/acceptencoding_test.go

@@ -0,0 +1,143 @@
+package compress
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_getCompressionType(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		values      []string
+		defaultType string
+		expected    string
+	}{
+		{
+			desc:     "br > gzip (no weight)",
+			values:   []string{"gzip, br"},
+			expected: brotliName,
+		},
+		{
+			desc:     "known compression type (no weight)",
+			values:   []string{"compress, gzip"},
+			expected: gzipName,
+		},
+		{
+			desc:     "unknown compression type (no weight), no encoding",
+			values:   []string{"compress, rar"},
+			expected: identityName,
+		},
+		{
+			desc:     "wildcard return the default compression type",
+			values:   []string{"*"},
+			expected: brotliName,
+		},
+		{
+			desc:        "wildcard return the custom default compression type",
+			values:      []string{"*"},
+			defaultType: "foo",
+			expected:    "foo",
+		},
+		{
+			desc:     "follows weight",
+			values:   []string{"br;q=0.8, gzip;q=1.0, *;q=0.1"},
+			expected: gzipName,
+		},
+		{
+			desc:     "ignore unknown compression type",
+			values:   []string{"compress;q=1.0, gzip;q=0.5"},
+			expected: gzipName,
+		},
+		{
+			desc:     "not acceptable (identity)",
+			values:   []string{"compress;q=1.0, identity;q=0"},
+			expected: notAcceptable,
+		},
+		{
+			desc:     "not acceptable (wildcard)",
+			values:   []string{"compress;q=1.0, *;q=0"},
+			expected: notAcceptable,
+		},
+		{
+			desc:     "non-zero is higher than 0",
+			values:   []string{"gzip, *;q=0"},
+			expected: gzipName,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			encodingType := getCompressionType(test.values, test.defaultType)
+
+			assert.Equal(t, test.expected, encodingType)
+		})
+	}
+}
+
+func Test_parseAcceptEncoding(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		values       []string
+		expected     []Encoding
+		assertWeight assert.BoolAssertionFunc
+	}{
+		{
+			desc:   "weight",
+			values: []string{"br;q=1.0, gzip;q=0.8, *;q=0.1"},
+			expected: []Encoding{
+				{Type: brotliName, Weight: ptr[float64](1)},
+				{Type: gzipName, Weight: ptr(0.8)},
+				{Type: wildcardName, Weight: ptr(0.1)},
+			},
+			assertWeight: assert.True,
+		},
+		{
+			desc:   "mixed",
+			values: []string{"gzip, br;q=1.0, *;q=0"},
+			expected: []Encoding{
+				{Type: brotliName, Weight: ptr[float64](1)},
+				{Type: gzipName},
+				{Type: wildcardName, Weight: ptr[float64](0)},
+			},
+			assertWeight: assert.True,
+		},
+		{
+			desc:   "no weight",
+			values: []string{"gzip, br, *"},
+			expected: []Encoding{
+				{Type: gzipName},
+				{Type: brotliName},
+				{Type: wildcardName},
+			},
+			assertWeight: assert.False,
+		},
+		{
+			desc:   "weight and identity",
+			values: []string{"gzip;q=1.0, identity; q=0.5, *;q=0"},
+			expected: []Encoding{
+				{Type: gzipName, Weight: ptr[float64](1)},
+				{Type: identityName, Weight: ptr(0.5)},
+				{Type: wildcardName, Weight: ptr[float64](0)},
+			},
+			assertWeight: assert.True,
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			aes, hasWeight := parseAcceptEncoding(test.values)
+
+			assert.Equal(t, test.expected, aes)
+			test.assertWeight(t, hasWeight)
+		})
+	}
+}
+
+func ptr[T any](t T) *T {
+	return &t
+}