fix(json-schema-2020-12-samples): fix examples for nullable primitive types defined as list of types (#10390)

Author: ctyar

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

@@ -67,7 +67,10 @@ export const foldType = (type) => {
     } else if (type.includes("object")) {
       return "object"
     } else {
-      const pickedType = randomPick(type)
+      const notNullTypes = type.filter((t) => t !== "null")
+      const pickedType = randomPick(
+        notNullTypes.length > 0 ? notNullTypes : type
+      )
       if (ALL_TYPES.includes(pickedType)) {
         return pickedType
       }

test/unit/core/plugins/json-schema-2020-12-samples/fn.js

@@ -373,6 +373,20 @@ describe("sampleFromSchema", () => {
     expect(sampleFromSchema(definition)).toEqual(expected)
   })
 
+  it("should handle nullable primitive types defined as list of types", function () {
+    const sample = (schema) => sampleFromSchema(fromJS(schema))
+
+    expect(sample({ type: ["string", "null"] })).toStrictEqual("string")
+    expect(sample({ type: ["null", "string"] })).toStrictEqual("string")
+    expect(sample({ type: ["number", "null"] })).toStrictEqual(0)
+    expect(sample({ type: ["null", "number"] })).toStrictEqual(0)
+    expect(sample({ type: ["integer", "null"] })).toStrictEqual(0)
+    expect(sample({ type: ["null", "integer"] })).toStrictEqual(0)
+    expect(sample({ type: ["boolean", "null"] })).toStrictEqual(true)
+    expect(sample({ type: ["null", "boolean"] })).toStrictEqual(true)
+    expect(sample({ type: ["null"] })).toStrictEqual(null)
+  })
+
   it("should return const value", function () {
     const definition = fromJS({ const: 3 })
     const expected = 3