feat(samples): add support for merging type keyword

This change is specific to JSON Schema 2020-12
and OpenAPI 3.1.0.

Refs #8577

src/core/plugins/json-schema-2020-12/samples-extensions/fn/core/merge.js

@@ -1,6 +1,7 @@
 /**
  * @prettier
  */
+import { normalizeArray as ensureArray } from "core/utils"
 import { isBooleanJSONSchema, isJSONSchema } from "./predicates"
 
 const merge = (target, source, config = {}) => {
@@ -18,6 +19,14 @@ const merge = (target, source, config = {}) => {
    */
   const merged = { ...source, ...target }
 
+  // merging the type keyword
+  if (source.type && target.type) {
+    if (Array.isArray(source.type) && typeof source.type === "string") {
+      const mergedType = ensureArray(source.type).concat(target.type)
+      merged.type = Array.from(new Set(mergedType))
+    }
+  }
+
   // merging required keyword
   if (Array.isArray(source.required) && Array.isArray(target.required)) {
     merged.required = [...new Set([...target.required, ...source.required])]