feat: switch ContentType from options pattern to fluent

http/constants.go

@@ -24,16 +24,19 @@ var (
 	ResponseChunkDelimeter = []byte("0\r\n") // An http/1.1 chunk delimeter, used for specifying an early end to the response
 )
 
+// ContentType represents a Content-Type descriptor for use with the response
+// Content-Type header or the request Accept header specifically for
+// Trustless Gateway requests and responses.
 type ContentType struct {
-	Mime       string
+	MimeType   string
 	Order      ContentTypeOrder
 	Duplicates bool
 	Quality    float32
 }
 
 func (ct ContentType) String() string {
 	sb := strings.Builder{}
-	sb.WriteString(ct.Mime)
+	sb.WriteString(ct.MimeType)
 	sb.WriteString(";version=")
 	sb.WriteString(MimeTypeCarVersion)
 	sb.WriteString(";order=")
@@ -51,55 +54,53 @@ func (ct ContentType) String() string {
 	return sb.String()
 }
 
-type ContentTypeOption func(ct *ContentType)
+// WithOrder returns a new ContentType with the specified order.
+func (ct ContentType) WithOrder(order ContentTypeOrder) ContentType {
+	ct.Order = order
+	return ct
+}
 
-func WithContentTypeOrder(order ContentTypeOrder) ContentTypeOption {
-	return func(ct *ContentType) {
-		ct.Order = order
-	}
+// WithDuplicates returns a new ContentType with the specified duplicates.
+func (ct ContentType) WithDuplicates(duplicates bool) ContentType {
+	ct.Duplicates = duplicates
+	return ct
 }
 
-func WithContentTypeDuplicates(duplicates bool) ContentTypeOption {
-	return func(ct *ContentType) {
-		ct.Duplicates = duplicates
-	}
+// WithMime returns a new ContentType with the specified mime type.
+func (ct ContentType) WithMimeType(mime string) ContentType {
+	ct.MimeType = mime
+	return ct
 }
 
-func WithContentTypeQuality(quality float32) ContentTypeOption {
-	return func(ct *ContentType) {
-		ct.Quality = quality
-	}
+// WithQuality returns a new ContentType with the specified quality.
+func (ct ContentType) WithQuality(quality float32) ContentType {
+	ct.Quality = quality
+	return ct
 }
 
-func NewContentType(opt ...ContentTypeOption) ContentType {
-	ct := ContentType{
-		Mime:       MimeTypeCar,
+func DefaultContentType() ContentType {
+	return ContentType{
+		MimeType:   MimeTypeCar,
 		Order:      DefaultOrder,
 		Duplicates: DefaultIncludeDupes,
 		Quality:    1,
 	}
-	for _, o := range opt {
-		o(&ct)
-	}
-	return ct
 }
 
 // ResponseContentTypeHeader returns the value for the Content-Type header for a
 // Trustless Gateway response which will vary depending on whether duplicates
 // are included or not. Otherwise, the header is the same for all responses.
 //
-// Deprecated: Use NewContentType().String() instead.
+// Deprecated: Use DefaultContentType().WithDuplicates(duplicates).String() instead.
 func ResponseContentTypeHeader(duplicates bool) string {
-	ct := NewContentType()
-	ct.Duplicates = duplicates
-	return ct.String()
+	return DefaultContentType().WithDuplicates(duplicates).String()
 }
 
 // RequestAcceptHeader returns the value for the Accept header for a Trustless
 // Gateway request which will vary depending on whether duplicates are included
 // or not. Otherwise, the header is the same for all requests.
 //
-// Deprecated: Use NewContentType().String() instead.
+// Deprecated: Use DefaultContentType().WithDuplicates(duplicates).String() instead.
 func RequestAcceptHeader(duplicates bool) string {
 	return ResponseContentTypeHeader(duplicates)
 }

http/constants_test.go

@@ -15,10 +15,10 @@ func TestContentType(t *testing.T) {
 	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=n", trustlesshttp.ResponseContentTypeHeader(false))
 	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=n", trustlesshttp.RequestAcceptHeader(false))
 
-	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y", trustlesshttp.NewContentType().String())
-	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y;q=0.8", trustlesshttp.NewContentType(trustlesshttp.WithContentTypeQuality(0.8)).String())
-	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y;q=0.333", trustlesshttp.NewContentType(trustlesshttp.WithContentTypeQuality(1.0/3.0)).String())
-	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y", trustlesshttp.NewContentType(trustlesshttp.WithContentTypeQuality(-1.0)).String())
-	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=n", trustlesshttp.NewContentType(trustlesshttp.WithContentTypeDuplicates(false)).String())
-	req.Equal("application/vnd.ipld.car;version=1;order=unk;dups=n", trustlesshttp.NewContentType(trustlesshttp.WithContentTypeDuplicates(false), trustlesshttp.WithContentTypeOrder(trustlesshttp.ContentTypeOrderUnk)).String())
+	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y", trustlesshttp.DefaultContentType().String())
+	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y;q=0.8", trustlesshttp.DefaultContentType().WithQuality(0.8).String())
+	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y;q=0.333", trustlesshttp.DefaultContentType().WithQuality(1.0/3.0).String())
+	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=y", trustlesshttp.DefaultContentType().WithQuality(-1.0).String())
+	req.Equal("application/vnd.ipld.car;version=1;order=dfs;dups=n", trustlesshttp.DefaultContentType().WithDuplicates(false).String())
+	req.Equal("application/vnd.ipld.car;version=1;order=unk;dups=n", trustlesshttp.DefaultContentType().WithDuplicates(false).WithOrder(trustlesshttp.ContentTypeOrderUnk).String())
 }

http/parse.go

@@ -97,7 +97,7 @@ func CheckFormat(req *http.Request) (ContentType, error) {
 	}
 
 	if validFormat {
-		return NewContentType(), nil // default is acceptable in this case (no accept but format=car)
+		return DefaultContentType(), nil // default is acceptable in this case (no accept but format=car)
 	}
 
 	return ContentType{}, fmt.Errorf("neither a valid Accept header nor format parameter were provided")
@@ -140,8 +140,7 @@ func parseContentType(header string, strictType bool) (ContentType, bool) {
 	typeParts := strings.Split(header, ";")
 	mime := strings.TrimSpace(typeParts[0])
 	if mime == MimeTypeCar || (!strictType && (mime == "*/*" || mime == "application/*")) {
-		contentType := NewContentType()
-		contentType.Mime = mime
+		contentType := DefaultContentType().WithMimeType(mime)
 		// parse additional car attributes outlined in IPIP-412
 		// https://specs.ipfs.tech/http-gateways/trustless-gateway/
 		for _, nextPart := range typeParts[1:] {