Merge pull request #826 from grafana/add-open-attribute

[CUE->OpenAPI] Add Manual Open Attribute for CUE -> OpenAPI Generation

Author: IfSentient

internal/ast/hints.go

@@ -27,6 +27,11 @@ const (
 	// HintStringFormatDateTime hints refers to a string that should be formatted
 	// as a datetime as defined by RFC 3339, section 5.6 (ex: 2017-07-21T17:32:28Z)
 	HintStringFormatDateTime = "string_format_datetime"
+
+	// HintOpenStruct hints that the struct is to be considered open even if not type Any
+	// when generating outputs which make explicit allowances for
+	// arbitrary additional properties, such as OpenAPI/JSONSchema.
+	HintOpenStruct = "open"
 )
 
 const DiscriminatorCatchAll = "cog_discriminator_catch_all"

internal/jennies/jsonschema/schema.go

@@ -202,6 +202,11 @@ func (jenny Schema) formatStruct(typeDef ast.Type) Definition {
 
 	definition.Set("type", "object")
 	definition.Set("additionalProperties", false)
+	if typeDef.HasHint(ast.HintOpenStruct) {
+		if val, _ := typeDef.Hints[ast.HintOpenStruct].(string); strings.ToLower(val)[0] == 't' {
+			definition.Set("additionalProperties", map[string]any{})
+		}
+	}
 
 	properties := orderedmap.New[string, any]()
 	var required []string

internal/simplecue/generator.go

@@ -404,6 +404,8 @@ func (g *generator) declareNode(v cue.Value) (ast.Type, error) {
 		}
 
 		def := ast.NewStruct(fields...)
+		// Add the hints since we can't supply them in the constructor
+		def.Hints = hints
 		def.Default = defVal
 
 		return def, nil