feat: Add WithResolverTransformer (#578)

erezrokah · web-flow · commit 5aeba0e1bec9 · 2023-01-05T23:54:05.000Z
For some plugins it's useful to configure a resolver based on the field's type: https://github.com/cloudquery/cloudquery/blob/876cc163d6dff277bb09a5147162a8646fcd98de/plugins/source/gcp/codegen/main.go#L263 I don't use the default one from `codegen` package like others as it returns `(string, error)` and we want to return a `schema.ColumnResolver` instead ---
diff --git a/transformers/struct.go b/transformers/struct.go
@@ -14,6 +14,7 @@ type structTransformer struct {
 	skipFields                    []string
 	nameTransformer               NameTransformer
 	typeTransformer               TypeTransformer
+	resolverTransformer           ResolverTransformer
 	ignoreInTestsTransformer      IgnoreInTestsTransformer
 	unwrapAllEmbeddedStructFields bool
 	structFieldsToUnwrap          []string
@@ -23,6 +24,12 @@ type NameTransformer func(reflect.StructField) (string, error)
 
 type TypeTransformer func(reflect.StructField) (schema.ValueType, error)
 
+type ResolverTransformer func(field reflect.StructField, path string) schema.ColumnResolver
+
+func DefaultResolverTransformer(_ reflect.StructField, path string) schema.ColumnResolver {
+	return schema.PathResolver(path)
+}
+
 type IgnoreInTestsTransformer func(field reflect.StructField) bool
 
 func DefaultIgnoreInTestsTransformer(_ reflect.StructField) bool {
@@ -71,12 +78,22 @@ func WithNameTransformer(transformer NameTransformer) StructTransformerOption {
 	}
 }
 
+// WithTypeTransformer overrides how column type will be determined.
+// DefaultTypeTransformer is used as the default.
 func WithTypeTransformer(transformer TypeTransformer) StructTransformerOption {
 	return func(t *structTransformer) {
 		t.typeTransformer = transformer
 	}
 }
 
+// WithResolverTransformer overrides how column resolver will be determined.
+// DefaultResolverTransformer is used as the default.
+func WithResolverTransformer(transformer ResolverTransformer) StructTransformerOption {
+	return func(t *structTransformer) {
+		t.resolverTransformer = transformer
+	}
+}
+
 // WithIgnoreInTestsTransformer overrides how column ignoreInTests will be determined.
 // DefaultIgnoreInTestsTransformer is used as the default.
 func WithIgnoreInTestsTransformer(transformer IgnoreInTestsTransformer) StructTransformerOption {
@@ -89,6 +106,7 @@ func TransformWithStruct(st any, opts ...StructTransformerOption) schema.Transfo
 	t := &structTransformer{
 		nameTransformer:          codegen.DefaultNameTransformer,
 		typeTransformer:          codegen.DefaultTypeTransformer,
+		resolverTransformer:      DefaultResolverTransformer,
 		ignoreInTestsTransformer: DefaultIgnoreInTestsTransformer,
 	}
 	for _, opt := range opts {
@@ -223,11 +241,17 @@ func (t *structTransformer) addColumnFromField(field reflect.StructField, parent
 	if t.table.Columns.Get(name) != nil {
 		return nil
 	}
+
+	resolver := t.resolverTransformer(field, path)
+	if resolver == nil {
+		resolver = DefaultResolverTransformer(field, path)
+	}
+
 	t.table.Columns = append(t.table.Columns,
 		schema.Column{
 			Name:          name,
 			Type:          columnType,
-			Resolver:      schema.PathResolver(path),
+			Resolver:      resolver,
 			IgnoreInTests: t.ignoreInTestsTransformer(field),
 		},
 	)
