fix: create nested types for map of array of objects

We were previously not nesting maps of arrays, and treating them as
generic types instead. This is an issue in Golang codegen, generating
generic Pulumi input/output types that don't exists. This commit ensures
we also flatten map of arrays so Golang codegen works.

Fixes: #147

pkg/codegen/customresourcegenerator.go

@@ -77,7 +77,7 @@ func flattenOpenAPI(sw *spec.Swagger) error {
 
 func flattenRecursively(sw *spec.Swagger, parentName string, currSpec spec.Schema) (spec.Schema, error) {
 	// If at bottom of the stack, return the spec.
-	if currSpec.Properties == nil && currSpec.Items == nil {
+	if currSpec.Properties == nil && currSpec.Items == nil && currSpec.AdditionalProperties == nil {
 		return currSpec, nil
 	}
 
@@ -86,43 +86,50 @@ func flattenRecursively(sw *spec.Swagger, parentName string, currSpec spec.Schem
 		return currSpec, nil
 	}
 
-	// If the property is an object with additional properties, we can skip it. We only care about
+	// If the property is an object with additional properties, we can skip it if it is not an array of inline objects. We only care about
 	// nested objects that are explicitly defined.
 	if currSpec.AdditionalProperties != nil {
+		// Not an array of inline objects, so we can skip processing.
+		if currSpec.AdditionalProperties.Schema.Items == nil {
+			return currSpec, nil
+		}
+
+		// Property is an array of inline objects.
+		s, ref, err := flattedArrayObject(parentName, sw, currSpec.AdditionalProperties.Schema.Items.Schema)
+		if err != nil {
+			return currSpec, fmt.Errorf("error flattening OpenAPI object of array property: %w", err)
+		}
+
+		currSpec.AdditionalProperties.Schema.Items.Schema = &s
+
+		if ref != nil {
+			currSpec.AdditionalProperties.Schema.Items.Schema.Ref = spec.Ref{Ref: *ref}
+			currSpec.AdditionalProperties.Schema.Items.Schema.Type = nil
+			currSpec.AdditionalProperties.Schema.Items.Schema.Properties = nil
+		}
+
 		return currSpec, nil
 	}
 
+	// If the property is an array, we need to remove any inline objects and replace them with references.
 	if currSpec.Items != nil {
 		if currSpec.Items.Schema == nil {
 			return currSpec, fmt.Errorf("error flattening OpenAPI spec: items schema is nil")
 		}
 
-		nestedDefinitionName := parentName
-
-		s, err := flattenRecursively(sw, nestedDefinitionName, *(currSpec.Items.Schema))
+		s, ref, err := flattedArrayObject(parentName, sw, currSpec.Items.Schema)
 		if err != nil {
-			return currSpec, fmt.Errorf("error flattening OpenAPI spec: %w", err)
+			return currSpec, fmt.Errorf("error flattening OpenAPI array property: %w", err)
 		}
 
 		currSpec.Items.Schema = &s
 
-		if len(currSpec.Items.Schema.Properties) == 0 {
-			return currSpec, nil
+		if ref != nil {
+			currSpec.Items.Schema.Ref = spec.Ref{Ref: *ref}
+			currSpec.Items.Schema.Type = nil
+			currSpec.Items.Schema.Properties = nil
 		}
 
-		sw.Definitions[nestedDefinitionName] = s
-
-		// Reset the property to be a reference to the nested object if the item is an object.
-		refName := definitionPrefix + nestedDefinitionName
-		ref, err := jsonreference.New(refName)
-		if err != nil {
-			return currSpec, fmt.Errorf("error creating OpenAPI json reference for nested object: %w", err)
-		}
-
-		currSpec.Items.Schema.Ref = spec.Ref{Ref: ref}
-		currSpec.Items.Schema.Type = nil
-		currSpec.Items.Schema.Properties = nil
-
 		return currSpec, nil
 	}
 
@@ -169,6 +176,30 @@ func flattenRecursively(sw *spec.Swagger, parentName string, currSpec spec.Schem
 	return currSpec, nil
 }
 
+// flattedArrayObject flattens an OpenAPI array property.
+func flattedArrayObject(parentName string, sw *spec.Swagger, itemsSchema *spec.Schema) (spec.Schema, *jsonreference.Ref, error) {
+	nestedDefinitionName := parentName
+
+	s, err := flattenRecursively(sw, nestedDefinitionName, *itemsSchema)
+	if err != nil {
+		return s, nil, fmt.Errorf("error flattening OpenAPI spec: %w", err)
+	}
+
+	if len(s.Properties) == 0 {
+		return s, nil, nil
+	}
+
+	sw.Definitions[nestedDefinitionName] = s
+
+	refName := definitionPrefix + nestedDefinitionName
+	ref, err := jsonreference.New(refName)
+	if err != nil {
+		return s, nil, fmt.Errorf("error creating OpenAPI json reference for nested object: %w", err)
+	}
+
+	return s, &ref, nil
+}
+
 func sanitizeReferenceName(fieldName string) string {
 	// If the field name is "arg" or "args", we need to change it to "Arguments" to avoid conflicts with Go reserved words.
 	if s := strings.ToLower(fieldName); s == "arg" || s == "args" {

tests/crds_test.go

@@ -177,6 +177,11 @@ func TestCRDsFromUrl(t *testing.T) {
 			name: "Argo Application Set",
 			url:  "https://raw.githubusercontent.com/argoproj/argo-cd/master/manifests/crds/applicationset-crd.yaml",
 		},
+		{
+			// https://github.com/pulumi/crd2pulumi/issues/147
+			name: "Prometheus Operator",
+			url:  "https://github.com/prometheus-operator/prometheus-operator/releases/download/v0.76.2/bundle.yaml",
+		},
 	}
 
 	for _, tt := range tests {