backend/http: support content-range response header

lib/rest/headers_test.go

@@ -0,0 +1,41 @@
+package rest
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseSizeFromHeaders(t *testing.T) {
+	testCases := []struct {
+		ContentLength, ContentRange string
+		Size                        int64
+	}{{
+		"", "", -1,
+	}, {
+		"42", "", 42,
+	}, {
+		"42", "invalid", -1,
+	}, {
+		"", "bytes 22-33/42", 42,
+	}, {
+		"12", "bytes 22-33/42", 42,
+	}, {
+		"12", "otherUnit 22-33/42", -1,
+	}, {
+		"12", "bytes 22-33/*", -1,
+	}, {
+		"0", "bytes */42", 42,
+	}}
+	for _, testCase := range testCases {
+		headers := make(http.Header, 2)
+		if len(testCase.ContentLength) > 0 {
+			headers.Set("Content-Length", testCase.ContentLength)
+		}
+		if len(testCase.ContentRange) > 0 {
+			headers.Set("Content-Range", testCase.ContentRange)
+		}
+		assert.Equalf(t, testCase.Size, ParseSizeFromHeaders(headers), "%+v", testCase)
+	}
+}