Support for long integers

Author: rochdev

README.md

@@ -27,6 +27,7 @@ fast-json-stringify obj x 4,976,369 ops/sec ±1.00% (89 runs sampled)
  - <a href="#patternProperties">`Pattern Properties`</a>
  - <a href="#additionalProperties">`Additional Properties`</a>
  - <a href="#ref">`Reuse - $ref`</a>
+ - <a href="#long">`Long integers`</a>
 - <a href="#acknowledgements">`Acknowledgements`</a>
 - <a href="#license">`License`</a>
 
@@ -294,6 +295,30 @@ const externalSchema = {
 const stringify = fastJson(schema, { schema: externalSchema })
 ```
 
+<a name="long"></a>
+#### Long integers
+Long integers (64-bit) are supported using the [long](https://github.com/dcodeIO/long.js) module.
+Example:
+```javascript
+const Long = require('long')
+
+const stringify = fastJson({
+  title: 'Example Schema',
+  type: 'object',
+  properties: {
+    id: {
+      type: 'integer'
+    }
+  }
+})
+
+const obj = {
+  id: Long.fromString('18446744073709551615', true)
+}
+
+console.log(stringify(obj)) // '{"id":18446744073709551615}'
+```
+
 <a name="acknowledgements"></a>
 ## Acknowledgements
 

index.js

@@ -2,6 +2,13 @@
 
 const fastSafeStringify = require('fast-safe-stringify')
 
+let isLong
+try {
+  isLong = require('long').isLong
+} catch (e) {
+  isLong = null
+}
+
 function build (schema, options) {
   options = options || {}
   /* eslint no-new-func: "off" */
@@ -20,6 +27,19 @@ function build (schema, options) {
     ${$asNull.toString()}
     ${$asBoolean.toString()}
   `
+
+  // only handle longs if the module is used
+  if (isLong) {
+    code += `
+      const isLong = ${isLong.toString()}
+      ${$asInteger.toString()}
+    `
+  } else {
+    code += `
+      const $asInteger = $asNumber
+    `
+  }
+
   var main
 
   switch (schema.type) {
@@ -31,6 +51,8 @@ function build (schema, options) {
       main = $asString.name
       break
     case 'integer':
+      main = $asInteger.name
+      break
     case 'number':
       main = $asNumber.name
       break
@@ -62,6 +84,14 @@ function $asNull () {
   return 'null'
 }
 
+function $asInteger (i) {
+  if (isLong && isLong(i)) {
+    return i.toString()
+  } else {
+    return $asNumber(i)
+  }
+}
+
 function $asNumber (i) {
   var num = Number(i)
   if (isNaN(num)) {
@@ -149,7 +179,11 @@ function addPatternProperties (schema, externalSchema, fullSchema) {
       code += `
           json += $asString(keys[i]) + ':' + $asString(obj[keys[i]]) + ','
       `
-    } else if (type === 'number' || type === 'integer') {
+    } else if (type === 'integer') {
+      code += `
+          json += $asString(keys[i]) + ':' + $asInteger(obj[keys[i]]) + ','
+      `
+    } else if (type === 'number') {
       code += `
           json += $asString(keys[i]) + ':' + $asNumber(obj[keys[i]]) + ','
       `
@@ -209,7 +243,11 @@ function additionalProperty (schema, externalSchema, fullSchema) {
     code += `
         json += $asString(keys[i]) + ':' + $asString(obj[keys[i]]) + ','
     `
-  } else if (type === 'number' || type === 'integer') {
+  } else if (type === 'integer') {
+    code += `
+        json += $asString(keys[i]) + ':' + $asInteger(obj[keys[i]]) + ','
+    `
+  } else if (type === 'number') {
     code += `
         json += $asString(keys[i]) + ':' + $asNumber(obj[keys[i]]) + ','
     `
@@ -365,8 +403,12 @@ function nested (laterCode, name, key, schema, externalSchema, fullSchema) {
         json += $asString(obj${key})
       `
       break
-    case 'number':
     case 'integer':
+      code += `
+        json += $asInteger(obj${key})
+      `
+      break
+    case 'number':
       code += `
         json += $asNumber(obj${key})
       `

package.json

@@ -26,6 +26,7 @@
   "devDependencies": {
     "benchmark": "^2.1.1",
     "is-my-json-valid": "^2.16.0",
+    "long": "^3.2.0",
     "pre-commit": "^1.1.3",
     "standard": "^10.0.0",
     "tap": "^10.3.0"

test/long.test.js

@@ -0,0 +1,22 @@
+'use strict'
+
+const test = require('tap').test
+const validator = require('is-my-json-valid')
+const Long = require('long')
+const build = require('..')
+
+test(`render a long as JSON`, (t) => {
+  t.plan(2)
+
+  const schema = {
+    title: 'long',
+    type: 'integer'
+  }
+
+  const validate = validator(schema)
+  const stringify = build(schema)
+  const output = stringify(Long.fromString('18446744073709551615', true))
+
+  t.equal(output, '18446744073709551615')
+  t.ok(validate(JSON.parse(output)), 'valid schema')
+})