Improve error handling

api/error.go

@@ -0,0 +1,42 @@
+package api
+
+import "net/http"
+
+type appError struct {
+	Error       error
+	Response    string
+	Code        int
+	ContentType string
+}
+
+func internalServerError(err error) *appError {
+	return &appError{Error: err, Response: "Internal server error", Code: http.StatusInternalServerError}
+}
+
+func notFound(err error) *appError {
+	return &appError{Error: err, Code: http.StatusNotFound}
+}
+
+func (e *appError) WithContentType(contentType string) *appError {
+	e.ContentType = contentType
+	return e
+}
+
+func (e *appError) WithCode(code int) *appError {
+	e.Code = code
+	return e
+}
+
+func (e *appError) WithResponse(response string) *appError {
+	e.Response = response
+	return e
+}
+
+func (e *appError) WithError(err error) *appError {
+	e.Error = err
+	return e
+}
+
+func (e *appError) IsJSON() bool {
+	return e.ContentType == APPLICATION_JSON
+}