Add ability to uglify generated code

README.md

@@ -7,14 +7,18 @@ advantages reduces on large payloads.
 Benchmarks:
 
 ```
-JSON.stringify array x 3,679 ops/sec ±1.01% (85 runs sampled)
-fast-json-stringify array x 4,618 ops/sec ±1.64% (87 runs sampled)
-JSON.stringify long string x 13,303 ops/sec ±1.01% (89 runs sampled)
-fast-json-stringify long string x 13,489 ops/sec ±0.88% (90 runs sampled)
-JSON.stringify short string x 4,974,749 ops/sec ±1.14% (86 runs sampled)
-fast-json-stringify short string x 11,030,700 ops/sec ±0.82% (89 runs sampled)
-JSON.stringify obj x 1,774,593 ops/sec ±1.07% (90 runs sampled)
-fast-json-stringify obj x 4,976,369 ops/sec ±1.00% (89 runs sampled)
+JSON.stringify array x 3,288 ops/sec ±5.18% (82 runs sampled)
+fast-json-stringify array x 1,813 ops/sec ±10.21% (71 runs sampled)
+fast-json-stringify-uglified array x 2,106 ops/sec ±3.23% (83 runs sampled)
+JSON.stringify long string x 12,933 ops/sec ±1.27% (87 runs sampled)
+fast-json-stringify long string x 12,221 ops/sec ±3.31% (84 runs sampled)
+fast-json-stringify-uglified long string x 13,256 ops/sec ±0.95% (92 runs sampled)
+JSON.stringify short string x 4,878,641 ops/sec ±1.14% (90 runs sampled)
+fast-json-stringify short string x 11,649,100 ops/sec ±0.98% (91 runs sampled)
+fast-json-stringify-uglified short string x 11,877,661 ops/sec ±0.91% (90 runs sampled)
+JSON.stringify obj x 1,705,377 ops/sec ±2.61% (87 runs sampled)
+fast-json-stringify obj x 2,268,915 ops/sec ±1.39% (90 runs sampled)
+fast-json-stringify-uglified obj x 2,243,341 ops/sec ±1.11% (89 runs sampled)
 ```
 
 #### Table of contents:
@@ -28,6 +32,7 @@ fast-json-stringify obj x 4,976,369 ops/sec ±1.00% (89 runs sampled)
  - <a href="#additionalProperties">`Additional Properties`</a>
  - <a href="#ref">`Reuse - $ref`</a>
  - <a href="#long">`Long integers`</a>
+ - <a href="#uglify">`Uglify`</a>
 - <a href="#acknowledgements">`Acknowledgements`</a>
 - <a href="#license">`License`</a>
 
@@ -319,6 +324,27 @@ const obj = {
 console.log(stringify(obj)) // '{"id":18446744073709551615}'
 ```
 
+<a name="uglify"></a>
+#### Uglify
+If you want to squeeze a little bit more performance out of the serialisation, at the cost of readability in the generated code, you can pass `uglify: true` as an option.
+Note that you have to manually install `uglify-es` in order for it to work. Only version 3 is supported.
+Example:
+```javascript
+
+const stringify = fastJson({
+  title: 'Example Schema',
+  type: 'object',
+  properties: {
+    id: {
+      type: 'integer'
+    }
+  }
+}, { uglify: true })
+
+// stringify is now minified code
+console.log(stringify({ some: 'object' })) // '{"some":"object"}'
+```
+
 <a name="acknowledgements"></a>
 ## Acknowledgements
 

bench.js

@@ -36,8 +36,11 @@ const obj = {
 const multiArray = []
 
 const stringify = require('.')(schema)
+const stringifyUgly = require('.')(schema, { uglify: true })
 const stringifyArray = require('.')(arraySchema)
+const stringifyArrayUgly = require('.')(arraySchema, { uglify: true })
 const stringifyString = require('.')({ type: 'string' })
+const stringifyStringUgly = require('.')({ type: 'string', uglify: true })
 var str = ''
 
 for (var i = 0; i < 10000; i++) {
@@ -61,6 +64,10 @@ suite.add('fast-json-stringify array', function () {
   stringifyArray(multiArray)
 })
 
+suite.add('fast-json-stringify-uglified array', function () {
+  stringifyArrayUgly(multiArray)
+})
+
 suite.add('JSON.stringify long string', function () {
   JSON.stringify(str)
 })
@@ -69,6 +76,10 @@ suite.add('fast-json-stringify long string', function () {
   stringifyString(str)
 })
 
+suite.add('fast-json-stringify-uglified long string', function () {
+  stringifyStringUgly(str)
+})
+
 suite.add('JSON.stringify short string', function () {
   JSON.stringify('hello world')
 })
@@ -77,6 +88,10 @@ suite.add('fast-json-stringify short string', function () {
   stringifyString('hello world')
 })
 
+suite.add('fast-json-stringify-uglified short string', function () {
+  stringifyStringUgly('hello world')
+})
+
 suite.add('JSON.stringify obj', function () {
   JSON.stringify(obj)
 })
@@ -85,6 +100,10 @@ suite.add('fast-json-stringify obj', function () {
   stringify(obj)
 })
 
+suite.add('fast-json-stringify-uglified obj', function () {
+  stringifyUgly(obj)
+})
+
 suite.on('cycle', cycle)
 
 suite.run()

index.js

@@ -2,6 +2,7 @@
 
 const fastSafeStringify = require('fast-safe-stringify')
 
+var uglify = null
 let isLong
 try {
   isLong = require('long').isLong
@@ -74,6 +75,11 @@ function build (schema, options) {
     ;
     return ${main}
   `
+
+  if (options.uglify) {
+    code = uglifyCode(code)
+  }
+
   if (hasAdditionalPropertiesTrue(schema)) {
     return (new Function('fastSafeStringify', code))(fastSafeStringify)
   }
@@ -457,4 +463,36 @@ function nested (laterCode, name, key, schema, externalSchema, fullSchema) {
   }
 }
 
+function uglifyCode (code) {
+  if (!uglify) {
+    loadUglify()
+  }
+
+  const uglified = uglify.minify(code, { parse: { bare_returns: true } })
+
+  if (uglified.error) {
+    throw uglified.error
+  }
+
+  return uglified.code
+}
+
+function loadUglify () {
+  try {
+    uglify = require('uglify-es')
+    const uglifyVersion = require('uglify-es/package.json').version
+
+    if (uglifyVersion[0] !== '3') {
+      throw new Error('Only version 3 of uglify-es is supported')
+    }
+  } catch (e) {
+    uglify = null
+    if (e.code === 'MODULE_NOT_FOUND') {
+      throw new Error('In order to use uglify, you have to manually install `uglify-es`')
+    }
+
+    throw e
+  }
+}
+
 module.exports = build

package.json

@@ -29,7 +29,8 @@
     "long": "^3.2.0",
     "pre-commit": "^1.1.3",
     "standard": "^10.0.0",
-    "tap": "^10.3.0"
+    "tap": "^10.3.0",
+    "uglify-es": "^3.0.9"
   },
   "dependencies": {
     "fast-safe-stringify": "^1.1.11"

test/basic.test.js

@@ -6,14 +6,18 @@ const build = require('..')
 
 function buildTest (schema, toStringify) {
   test(`render a ${schema.title} as JSON`, (t) => {
-    t.plan(3)
+    t.plan(5)
 
     const validate = validator(schema)
     const stringify = build(schema)
+    const stringifyUgly = build(schema, {uglify: true})
     const output = stringify(toStringify)
+    const outputUglify = stringifyUgly(toStringify)
 
     t.deepEqual(JSON.parse(output), toStringify)
+    t.deepEqual(JSON.parse(outputUglify), toStringify)
     t.equal(output, JSON.stringify(toStringify))
+    t.equal(outputUglify, JSON.stringify(toStringify))
     t.ok(validate(JSON.parse(output)), 'valid schema')
   })
 }