From de6ba3e61506275da0957e74372da91227c5240e Mon Sep 17 00:00:00 2001
From: Shivam Kumar Jha <info@shivamjha.com>
Date: Fri, 26 Jul 2024 19:32:01 +0530
Subject: [PATCH 1/3] new option added: stripNull, which removes null in
 serialised output

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 862c7c83..6bc0c744 100644
--- a/index.js
+++ b/index.js
@@ -374,7 +374,7 @@ function buildInnerObject (context, location) {
 
     code += `
       value = obj[${sanitizedKey}]
-      if (value !== undefined) {
+      if ${context.options.stripNull ? '(value != null)' : '(value !== undefined)'} {
         ${addComma}
         json += ${JSON.stringify(sanitizedKey + ':')}
         ${buildValue(context, propertyLocation, 'value')}

From 5e01a5d8d7fed19c992739f351ba974fe46b0add Mon Sep 17 00:00:00 2001
From: Shivam Kumar Jha <info@shivamjha.com>
Date: Sat, 27 Jul 2024 09:56:53 +0530
Subject: [PATCH 2/3] tests added for strip null feature

---
 test/stripNull.test.js | 110 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 test/stripNull.test.js

diff --git a/test/stripNull.test.js b/test/stripNull.test.js
new file mode 100644
index 00000000..c2eedea5
--- /dev/null
+++ b/test/stripNull.test.js
@@ -0,0 +1,110 @@
+const test = require('tap').test
+const build = require('..')
+
+test('should handle null string values properly', (t) => {
+  t.plan(3)
+
+  const schema = {
+    type: 'object',
+    properties: {
+      firstName: { type: 'string' },
+      lastName: { type: 'string' }
+    },
+    required: ['firstName']
+  }
+  const stringify = build(schema, { stripNull: true })
+
+  const json1 = { firstName: 'Matteo', lastName: 'Collina' }
+  t.equal(stringify(json1), '{"firstName":"Matteo","lastName":"Collina"}')
+
+  const json2 = { firstName: 'Matteo', lastName: null }
+  t.equal(stringify(json2), '{"firstName":"Matteo"}')
+
+  const json3 = { firstName: null, lastName: 'Collina' }
+  t.throws(() => stringify(json3)) // throw error when required property is missing
+})
+
+test('should handle null int values properly', (t) => {
+  t.plan(3)
+
+  const schema = {
+    type: 'object',
+    properties: {
+      name: { type: 'string' },
+      age: { type: 'integer' },
+      experience: { type: 'integer' }
+    }
+  }
+  const stringify = build(schema, { stripNull: true })
+
+  const json1 = { name: 'Matteo', age: 32, experience: 12 }
+  t.equal(stringify(json1), '{"name":"Matteo","age":32,"experience":12}')
+
+  const json2 = { name: 'Matteo', age: null, experience: null }
+  t.equal(stringify(json2), '{"name":"Matteo"}')
+
+  const json3 = { name: 'Matteo', age: 3, experience: null }
+  t.equal(stringify(json3), '{"name":"Matteo","age":3}')
+})
+
+test('should handle arrays properly', (t) => {
+  t.plan(1)
+
+  const schema = {
+    type: 'object',
+    properties: {
+      name: { type: 'string' },
+      experience: {
+        type: 'array',
+        items: {
+          type: 'object',
+          properties: {
+            company: { type: 'string' },
+            years: { type: 'integer' }
+          }
+        }
+      }
+    }
+  }
+  const stringify = build(schema, { stripNull: true })
+
+  const json1 = {
+    name: 'Matteo',
+    experience: [
+      { company: 'C1', years: 12 },
+      { company: 'C2', years: null },
+      { company: null, years: 6 },
+      { company: null, years: null }
+    ]
+  }
+
+  t.equal(
+    stringify(json1),
+    '{"name":"Matteo","experience":[{"company":"C1","years":12},{"company":"C2"},{"years":6},{}]}'
+  )
+})
+
+test('should handle objects and nested objects properly', (t) => {
+  t.plan(2)
+
+  const schema = {
+    type: 'object',
+    properties: {
+      name: { type: 'string' },
+      address: {
+        type: 'object',
+        properties: {
+          city: { type: 'string' },
+          country: { type: 'string' }
+        }
+      }
+    }
+  }
+  const stringify = build(schema, { stripNull: true })
+
+  const json1 = { name: 'Matteo', address: { city: 'Mumbai', country: null } }
+  t.equal(stringify(json1), '{"name":"Matteo","address":{"city":"Mumbai"}}')
+
+  const json2 = { name: null, address: { city: null, country: 'India' } }
+  t.equal(stringify(json2), '{"address":{"country":"India"}}')
+})

From 8dc2705501235dbd4305581db4fb10c252823975 Mon Sep 17 00:00:00 2001
From: Shivam Kumar Jha <info@shivamjha.com>
Date: Sat, 27 Jul 2024 10:02:38 +0530
Subject: [PATCH 3/3] updated README and type info with strip null details

---
 README.md        | 1 +
 types/index.d.ts | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/README.md b/README.md
index f3a0d206..6a574472 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,7 @@ const stringify = fastJson(mySchema, {
 - `rounding`: setup how the `integer` types will be rounded when not integers. [More details](#integer)
 - `largeArrayMechanism`: set the mechanism that should be used to handle large
 (by default `20000` or more items) arrays. [More details](#largearrays)
+- `stripNull`: removes keys with null values from serialised output. If you have lots of null values, using this will result in smallerpayload and improved performance.
 
 
 <a name="api"></a>
diff --git a/types/index.d.ts b/types/index.d.ts
index 5ded284d..6dab922f 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -187,6 +187,13 @@ declare namespace build {
      * @default 'default'
      */
     largeArrayMechanism?: 'default' | 'json-stringify'
+
+    /**
+     * Specify if null key-value are removed from serialised JSON output, for a smaller payload
+     *
+     * @default 'false'
+     */
+    stripNull?: boolean
   }
 
   export const validLargeArrayMechanisms: string[]