fix: coerce non-nullable schema null object to {}

index.js

@@ -560,23 +560,10 @@ function buildObject (context, location) {
   let functionCode = `
   `
 
-  let checkNullableCode = `
-  `
-  const nullable = schema.nullable === true
-  if (!nullable) {
-    // use schemaRef in the hope there's anything useful for which schema is detecting the issue
-    checkNullableCode += `
-    if (obj === null) {
-      throw new Error('schema: ${schemaRef} is not nullable, received null input!')
-    }
-    `
-  }
-
   functionCode += `
     // ${schemaRef}
     function ${functionName} (input) {
-      const obj = ${toJSON('input')}
-      ${checkNullableCode}
+      const obj = ${toJSON('input')} || {}
 
       ${buildInnerObject(context, location)}
     }

test/basic.test.js

@@ -376,32 +376,6 @@ test('render a double quote as JSON /2', (t) => {
   t.ok(validate(JSON.parse(output)), 'valid schema')
 })
 
-test('should error on non-nullable', t => {
-  t.plan(1)
-  const schema = {
-    title: 'non-nullable schema error',
-    type: 'object',
-    properties: {
-      firstName: {
-        type: 'string'
-      },
-      lastName: {
-        type: 'string'
-      }
-    },
-    required: ['firstName', 'lastName']
-  }
-
-  try {
-    const stringify = build(schema)
-    stringify(null)
-    t.fail('stringify should throw for null doc validated on non-nullable schema')
-  } catch (err) {
-    const message = err.message
-    t.equal(message, 'schema: # is not nullable, received null input!')
-  }
-})
-
 test('render a long string', (t) => {
   t.plan(2)
 

test/toJSON.test.js

@@ -127,7 +127,7 @@ test('not fail on null sub-object declared nullable', (t) => {
   t.equal('{"product":null}', stringify(object))
 })
 
-test('throw an error on non nullable null sub-object', (t) => {
+test('on non nullable null sub-object it should coerce to {}', (t) => {
   t.plan(1)
 
   const stringify = build({
@@ -148,10 +148,12 @@ test('throw an error on non nullable null sub-object', (t) => {
   const object = {
     product: null
   }
-  t.throws(() => { stringify(object) })
+
+  const result = stringify(object)
+  t.equal(result, JSON.stringify({ product: {} }))
 })
 
-test('throw an error on non nullable null object', (t) => {
+test('on non nullable null object it should coerce to {}', (t) => {
   t.plan(1)
 
   const stringify = build({
@@ -170,5 +172,37 @@ test('throw an error on non nullable null object', (t) => {
       }
     }
   })
-  t.throws(() => { stringify(null) })
+
+  const result = stringify(null)
+  t.equal(result, '{}')
+})
+
+test('on non-nullable null object with required fields it should throw complaining missing required fields', (t) => {
+  t.plan(1)
+
+  const stringify = build({
+    title: 'simple object',
+    nullable: false,
+    type: 'object',
+    properties: {
+      product: {
+        nullable: false,
+        type: 'object',
+        properties: {
+          name: {
+            type: 'string'
+          }
+        }
+      }
+    },
+    required: ['product']
+  })
+
+  try {
+    stringify(null)
+    t.fail('stringify should throw for missing required fields')
+  } catch (err) {
+    const message = err.message
+    t.equal(message, '"product" is required!')
+  }
 })