Merge pull request #32 from etesami/validate-fromcompositepath-or-value

Validate Value and ValueFromFieldPath are not nil

Author: phisco

fn.go

@@ -116,7 +116,7 @@ func (f *Function) RunFunction(_ context.Context, req *fnv1beta1.RunFunctionRequ
 
 // Build requirements takes input and outputs an array of external resoruce requirements to request
 // from Crossplane's external resource API.
-func buildRequirements(in *v1beta1.Input, xr *resource.Composite) (*fnv1beta1.Requirements, error) {
+func buildRequirements(in *v1beta1.Input, xr *resource.Composite) (*fnv1beta1.Requirements, error) { //nolint:gocyclo // Adding non-nil validations increases function complexity.
 	extraResources := make(map[string]*fnv1beta1.ResourceSelector, len(in.Spec.ExtraResources))
 	for _, extraResource := range in.Spec.ExtraResources {
 		extraResName := extraResource.Into
@@ -134,9 +134,14 @@ func buildRequirements(in *v1beta1.Input, xr *resource.Composite) (*fnv1beta1.Re
 			for _, selector := range extraResource.Selector.MatchLabels {
 				switch selector.GetType() {
 				case v1beta1.ResourceSourceSelectorLabelMatcherTypeValue:
-					// TODO validate value not to be nil
+					if selector.Value == nil {
+						return nil, errors.New("Value cannot be nil for type 'Value'")
+					}
 					matchLabels[selector.Key] = *selector.Value
 				case v1beta1.ResourceSourceSelectorLabelMatcherTypeFromCompositeFieldPath:
+					if selector.ValueFromFieldPath == nil {
+						return nil, errors.New("ValueFromFieldPath cannot be nil for type 'FromCompositeFieldPath'")
+					}
 					value, err := fieldpath.Pave(xr.Resource.Object).GetString(*selector.ValueFromFieldPath)
 					if err != nil {
 						if !selector.FromFieldPathIsOptional() {