fix(sample-gen): respect null values in examples

src/core/plugins/samples/fn.js

@@ -29,6 +29,7 @@ export const sampleFromSchema = (schema, config={}) => {
   let { type, example, properties, additionalProperties, items } = objectify(schema)
   let { includeReadOnly, includeWriteOnly } = config
 
+
   if(example !== undefined) {
     return deeplyStripKey(example, "$$ref", (val) => {
       // do a couple of quick sanity tests to ensure the value

src/core/utils.js

@@ -742,7 +742,7 @@ export const getCommonExtensions = (defObj) => defObj.filter((v, k) => /^pattern
 // `predicate` can be used to discriminate the stripping further,
 // by preserving the key's place in the object based on its value.
 export function deeplyStripKey(input, keyToStrip, predicate = () => true) {
-  if(typeof input !== "object" || Array.isArray(input) || !keyToStrip) {
+  if(typeof input !== "object" || Array.isArray(input) || input === null || !keyToStrip) {
     return input
   }
 

test/core/plugins/samples/fn.js

@@ -379,6 +379,46 @@ describe("sampleFromSchema", function() {
 
       expect(sampleFromSchema(definition)).toEqual(expected)
     })
+
+    it("returns null for a null example", function() {
+      var definition = {
+        "type": "object",
+        "properties": {
+          "foo": {
+            "type": "string",
+            "nullable": true,
+            "example": null
+          }
+        }
+      }
+
+      var expected = {
+        foo: null
+      }
+
+      expect(sampleFromSchema(definition)).toEqual(expected)
+    })
+
+    it("returns null for a null object-level example", function() {
+      var definition = {
+        "type": "object",
+        "properties": {
+          "foo": {
+            "type": "string",
+            "nullable": true
+          }
+        },
+        "example": {
+          "foo": null
+        }
+      }
+
+      var expected = {
+        foo: null
+      }
+
+      expect(sampleFromSchema(definition)).toEqual(expected)
+    })
   })
 })