Task filters (#243)

Fix not returning errors

Fix integration tests

Add more tests

Make task filtering actually work

Change tests

Fix using filter conditions

Fix test

Remove unused fields

Fix static check

Remove start and end date fields on task collection

Fix misspell

add filter logic when getting tasks

Add parsing filter query parameters into task filters

Start adding support for filters

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/243

pkg/models/error.go

@@ -653,6 +653,60 @@ func (err ErrTaskCommentDoesNotExist) HTTPError() web.HTTPError {
 	}
 }
 
+// ErrInvalidTaskField represents an error where the provided task field is invalid
+type ErrInvalidTaskField struct {
+	TaskField string
+}
+
+// IsErrInvalidTaskField checks if an error is ErrInvalidTaskField.
+func IsErrInvalidTaskField(err error) bool {
+	_, ok := err.(ErrInvalidTaskField)
+	return ok
+}
+
+func (err ErrInvalidTaskField) Error() string {
+	return fmt.Sprintf("Task Field is invalid [TaskField: %s]", err.TaskField)
+}
+
+// ErrCodeInvalidTaskField holds the unique world-error code of this error
+const ErrCodeInvalidTaskField = 4016
+
+// HTTPError holds the http error description
+func (err ErrInvalidTaskField) HTTPError() web.HTTPError {
+	return web.HTTPError{
+		HTTPCode: http.StatusBadRequest,
+		Code:     ErrCodeInvalidTaskField,
+		Message:  fmt.Sprintf("The task field '%s' is invalid.", err.TaskField),
+	}
+}
+
+// ErrInvalidTaskFilterComparator represents an error where the provided task field is invalid
+type ErrInvalidTaskFilterComparator struct {
+	Comparator taskFilterComparator
+}
+
+// IsErrInvalidTaskFilterComparator checks if an error is ErrInvalidTaskFilterComparator.
+func IsErrInvalidTaskFilterComparator(err error) bool {
+	_, ok := err.(ErrInvalidTaskFilterComparator)
+	return ok
+}
+
+func (err ErrInvalidTaskFilterComparator) Error() string {
+	return fmt.Sprintf("Task filter comparator is invalid [Comparator: %s]", err.Comparator)
+}
+
+// ErrCodeInvalidTaskFilterComparator holds the unique world-error code of this error
+const ErrCodeInvalidTaskFilterComparator = 4017
+
+// HTTPError holds the http error description
+func (err ErrInvalidTaskFilterComparator) HTTPError() web.HTTPError {
+	return web.HTTPError{
+		HTTPCode: http.StatusBadRequest,
+		Code:     ErrCodeInvalidTaskFilterComparator,
+		Message:  fmt.Sprintf("The task filter comparator '%s' is invalid.", err.Comparator),
+	}
+}
+
 // =================
 // Namespace errors
 // =================