Evaluate multiple functions.

Author: mcollina

index.js

@@ -2,28 +2,89 @@
 
 function build (schema) {
   /*eslint no-new-func: "off"*/
-
-  let code = `
+  var code = `
     'use strict'
-    let json = '{'
+
+    ${$asString.toString()}
+    ${$asNumber.toString()}
+  `
+  var main
+
+  switch (schema.type) {
+    case 'object':
+      main = '$main'
+      code = buildObject(schema, code, main)
+      break
+    case 'string':
+      main = $asString.name
+      break
+    case 'integer':
+    case 'number':
+      main = $asNumber.name
+      break
+    default:
+      throw new Error(`${schema.type} unsupported`)
+  }
+
+  code += `
+    ;
+    return ${main}
+  `
+
+  return (new Function(code))()
+}
+
+function $asNumber (i) {
+  var num = Number(i)
+  if (isNaN(num)) {
+    return 'null'
+  } else {
+    return '' + i
+  }
+}
+
+function $asString (s) {
+  var str = s.toString()
+  var result = ''
+  var last = 0
+  var l = str.length
+  for (var i = 0; i < l; i++) {
+    if (str[i] === '"') {
+      result += str.slice(last, i) + '\\"'
+      last = i + 1
+    }
+  }
+  if (last === 0) {
+    result = str
+  } else {
+    result += str.slice(last)
+  }
+  return '"' + result + '"'
+}
+
+function buildObject (schema, code, name) {
+  code += `
+    function ${name} (obj) {
+      var json = '{'
   `
 
   Object.keys(schema.properties).forEach((key, i, a) => {
     const type = schema.properties[key].type
 
     code += `
-      json += '"${key}":'
+      json += '${$asString(key)}:'
     `
 
     switch (type) {
       case 'string':
         code += `
-          json += '"' + obj.${key} + '"'
+          json += $asString(obj.${key})
         `
         break
+      case 'number':
       case 'integer':
         code += `
-          json += '' + obj.${key}
+          json += $asNumber(obj.${key})
         `
         break
       default:
@@ -36,11 +97,12 @@ function build (schema) {
   })
 
   code += `
-    json += '}'
-    return json
+      json += '}'
+      return json
+    }
   `
 
-  return new Function('obj', code)
+  return code
 }
 
 module.exports = build

test.js

@@ -3,8 +3,20 @@
 const test = require('tap').test
 const build = require('.')
 
-const example = {
-  'title': 'Example Schema',
+function buildTest (schema, toStringify) {
+  test(`render a ${schema.title} as JSON`, (t) => {
+    t.plan(2)
+
+    const stringify = build(schema)
+    const output = stringify(toStringify)
+
+    t.deepEqual(JSON.parse(output), toStringify)
+    t.equal(output, JSON.stringify(toStringify))
+  })
+}
+
+buildTest({
+  'title': 'basic',
   'type': 'object',
   'properties': {
     'firstName': {
@@ -17,23 +29,30 @@ const example = {
       'description': 'Age in years',
       'type': 'integer',
       'minimum': 0
+    },
+    'magic': {
+      'type': 'number'
     }
   },
   'required': ['firstName', 'lastName']
-}
-
-test('render a basic json', (t) => {
-  t.plan(2)
+}, {
+  firstName: 'Matteo',
+  lastName: 'Collina',
+  age: 32,
+  magic: 42.42
+})
 
-  const stringify = build(example)
-  const obj = {
-    firstName: 'Matteo',
-    lastName: 'Collina',
-    age: 32
-  }
+buildTest({
+  title: 'string',
+  type: 'string'
+}, 'hello world')
 
-  const output = stringify(obj)
+buildTest({
+  title: 'an integer',
+  type: 'integer'
+}, 42)
 
-  t.deepEqual(JSON.parse(output), obj)
-  t.equal(output, JSON.stringify(obj))
-})
+buildTest({
+  title: 'a number',
+  type: 'number'
+}, 42.42)