diff --git a/index.js b/index.js
index 5dfaf7ed..760f497b 100644
--- a/index.js
+++ b/index.js
@@ -1,7 +1,7 @@
 'use strict'
 
 function build (schema) {
-  /*eslint no-new-func: "off"*/
+  /* eslint no-new-func: "off" */
   var code = `
     'use strict'
   `
diff --git a/package.json b/package.json
index f7ee8388..e9128c35 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "Stringify your JSON at max speed",
   "main": "index.js",
   "scripts": {
-    "test": "standard && tap test.js"
+    "test": "standard && tap test/*.test.js"
   },
   "precommit": "test",
   "repository": {
@@ -25,10 +25,9 @@
   "homepage": "https://github.com/mcollina/fast-json-stringify#readme",
   "devDependencies": {
     "benchmark": "^2.1.1",
-    "fast-safe-stringify": "^1.0.9",
-    "is-my-json-valid": "^2.13.1",
+    "is-my-json-valid": "^2.14.0",
     "pre-commit": "^1.1.3",
-    "standard": "^7.1.2",
-    "tap": "^6.2.0"
+    "standard": "^8.2.0",
+    "tap": "^7.1.2"
   }
 }
diff --git a/test.js b/test.js
deleted file mode 100644
index 26824a4d..00000000
--- a/test.js
+++ /dev/null
@@ -1,475 +0,0 @@
-'use strict'
-
-const test = require('tap').test
-const validator = require('is-my-json-valid')
-const build = require('.')
-
-function buildTest (schema, toStringify) {
-  test(`render a ${schema.title} as JSON`, (t) => {
-    t.plan(3)
-
-    const validate = validator(schema)
-    const stringify = build(schema)
-    const output = stringify(toStringify)
-
-    t.deepEqual(JSON.parse(output), toStringify)
-    t.equal(output, JSON.stringify(toStringify))
-    t.ok(validate(JSON.parse(output)), 'valid schema')
-  })
-}
-
-buildTest({
-  'title': 'basic',
-  'type': 'object',
-  'properties': {
-    'firstName': {
-      'type': 'string'
-    },
-    'lastName': {
-      'type': 'string'
-    },
-    'age': {
-      'description': 'Age in years',
-      'type': 'integer',
-      'minimum': 0
-    },
-    'magic': {
-      'type': 'number'
-    }
-  },
-  'required': ['firstName', 'lastName']
-}, {
-  firstName: 'Matteo',
-  lastName: 'Collina',
-  age: 32,
-  magic: 42.42
-})
-
-buildTest({
-  title: 'string',
-  type: 'string'
-}, 'hello world')
-
-buildTest({
-  title: 'string with quotes',
-  type: 'string'
-}, 'hello """" world')
-
-buildTest({
-  title: 'boolean true',
-  type: 'boolean'
-}, true)
-
-buildTest({
-  title: 'boolean false',
-  type: 'boolean'
-}, false)
-
-buildTest({
-  title: 'an integer',
-  type: 'integer'
-}, 42)
-
-buildTest({
-  title: 'a number',
-  type: 'number'
-}, 42.42)
-
-buildTest({
-  'title': 'deep',
-  'type': 'object',
-  'properties': {
-    'firstName': {
-      'type': 'string'
-    },
-    'lastName': {
-      'type': 'string'
-    },
-    'more': {
-      'description': 'more properties',
-      'type': 'object',
-      'properties': {
-        'something': {
-          'type': 'string'
-        }
-      }
-    }
-  }
-}, {
-  firstName: 'Matteo',
-  lastName: 'Collina',
-  more: {
-    something: 'else'
-  }
-})
-
-buildTest({
-  'title': 'null',
-  'type': 'null'
-}, null)
-
-buildTest({
-  'title': 'with null',
-  'type': 'object',
-  'properties': {
-    'firstName': {
-      'type': 'null'
-    }
-  }
-}, {
-  firstName: null
-})
-
-buildTest({
-  'title': 'array with objects',
-  'type': 'array',
-  'items': {
-    'type': 'object',
-    'properties': {
-      'name': {
-        'type': 'string'
-      }
-    }
-  }
-}, [{
-  name: 'Matteo'
-}, {
-  name: 'Dave'
-}])
-
-buildTest({
-  'title': 'array with strings',
-  'type': 'array',
-  'items': {
-    'type': 'string'
-  }
-}, [
-  'Matteo',
-  'Dave'
-])
-
-buildTest({
-  'title': 'array with numbers',
-  'type': 'array',
-  'items': {
-    'type': 'number'
-  }
-}, [
-  42.42,
-  24
-])
-
-buildTest({
-  'title': 'array with integers',
-  'type': 'array',
-  'items': {
-    'type': 'number'
-  }
-}, [
-  42,
-  24
-])
-
-buildTest({
-  'title': 'nested array with objects',
-  'type': 'object',
-  'properties': {
-    'data': {
-      'type': 'array',
-      'items': {
-        'type': 'object',
-        'properties': {
-          'name': {
-            'type': 'string'
-          }
-        }
-      }
-    }
-  }
-}, {
-  data: [{
-    name: 'Matteo'
-  }, {
-    name: 'Dave'
-  }]
-})
-
-test('render a a date in a string as JSON', (t) => {
-  t.plan(2)
-
-  const schema = {
-    title: 'a date in a string',
-    type: 'string'
-  }
-  const toStringify = new Date()
-
-  const validate = validator(schema)
-  const stringify = build(schema)
-  const output = stringify(toStringify)
-
-  t.equal(output, JSON.stringify(toStringify))
-  t.ok(validate(JSON.parse(output)), 'valid schema')
-})
-
-buildTest({
-  'title': 'object with boolean',
-  'type': 'object',
-  'properties': {
-    'readonly': {
-      'type': 'boolean'
-    }
-  }
-}, {
-  readonly: true
-})
-
-test('object with RexExp', (t) => {
-  t.plan(3)
-
-  const schema = {
-    title: 'object with RegExp',
-    type: 'object',
-    properties: {
-      reg: {
-        type: 'string'
-      }
-    }
-  }
-
-  const obj = {
-    reg: /"([^"]|\\")*"/
-  }
-
-  const stringify = build(schema)
-  const validate = validator(schema)
-  const output = stringify(obj)
-
-  try {
-    JSON.parse(output)
-    t.pass()
-  } catch (e) {
-    t.fail()
-  }
-
-  t.equal(obj.reg.source, new RegExp(JSON.parse(output).reg).source)
-  t.ok(validate(JSON.parse(output)), 'valid schema')
-})
-
-test('object with required field', (t) => {
-  t.plan(3)
-
-  const schema = {
-    title: 'object with required field',
-    type: 'object',
-    properties: {
-      str: {
-        type: 'string'
-      },
-      num: {
-        type: 'integer'
-      }
-    },
-    required: ['str']
-  }
-  const stringify = build(schema)
-
-  try {
-    stringify({
-      str: 'string'
-    })
-    t.pass()
-  } catch (e) {
-    t.fail()
-  }
-
-  try {
-    stringify({
-      num: 42
-    })
-    t.fail()
-  } catch (e) {
-    t.is(e.message, 'str is required!')
-    t.pass()
-  }
-})
-
-test('missing values', (t) => {
-  t.plan(3)
-
-  const stringify = build({
-    title: 'object with missing values',
-    type: 'object',
-    properties: {
-      str: {
-        type: 'string'
-      },
-      num: {
-        type: 'number'
-      },
-      val: {
-        type: 'string'
-      }
-    }
-  })
-
-  t.equal('{"val":"value"}', stringify({ val: 'value' }))
-  t.equal('{"str":"string","val":"value"}', stringify({ str: 'string', val: 'value' }))
-  t.equal('{"str":"string","num":42,"val":"value"}', stringify({ str: 'string', num: 42, val: 'value' }))
-})
-
-test('patternProperties', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'patternProperties',
-    type: 'object',
-    properties: {
-      str: {
-        type: 'string'
-      }
-    },
-    patternProperties: {
-      'foo': {
-        type: 'string'
-      }
-    }
-  })
-
-  let obj = { str: 'test', foo: 42, ofoo: true, foof: 'string', objfoo: {a: true}, notMe: false }
-  t.equal('{"foo":"42","ofoo":"true","foof":"string","objfoo":"[object Object]","str":"test"}', stringify(obj))
-})
-
-test('patternProperties should not change properties', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'patternProperties should not change properties',
-    type: 'object',
-    properties: {
-      foo: {
-        type: 'string'
-      }
-    },
-    patternProperties: {
-      foo: {
-        type: 'number'
-      }
-    }
-  })
-
-  const obj = { foo: '42', ofoo: 42 }
-  t.equal('{"ofoo":42,"foo":"42"}', stringify(obj))
-})
-
-test('patternProperties - string coerce', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check string coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'string'
-      }
-    }
-  })
-
-  const obj = { foo: true, ofoo: 42, arrfoo: ['array', 'test'], objfoo: { a: 'world' } }
-  t.equal('{"foo":"true","ofoo":"42","arrfoo":"array,test","objfoo":"[object Object]"}', stringify(obj))
-})
-
-test('patternProperties - number coerce', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check number coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'number'
-      }
-    }
-  })
-
-  const obj = { foo: true, ofoo: '42', xfoo: 'string', arrfoo: [1, 2], objfoo: { num: 42 } }
-  t.equal('{"foo":1,"ofoo":42,"xfoo":null,"arrfoo":null,"objfoo":null}', stringify(obj))
-})
-
-test('patternProperties - boolean coerce', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check boolean coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'boolean'
-      }
-    }
-  })
-
-  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { a: true } }
-  t.equal('{"foo":true,"ofoo":false,"arrfoo":true,"objfoo":true}', stringify(obj))
-})
-
-test('patternProperties - object coerce', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check object coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'object',
-        properties: {
-          answer: {
-            type: 'number'
-          }
-        }
-      }
-    }
-  })
-
-  const obj = { objfoo: { answer: 42 } }
-  t.equal('{"objfoo":{"answer":42}}', stringify(obj))
-})
-
-test('patternProperties - array coerce', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check array coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'array',
-        items: {
-          type: 'string'
-        }
-      }
-    }
-  })
-
-  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { tyrion: 'lannister' } }
-  t.equal('{"foo":["t","r","u","e"],"ofoo":[],"arrfoo":["1","2"],"objfoo":[]}', stringify(obj))
-})
-
-test('patternProperties - throw on unknown type', (t) => {
-  t.plan(1)
-  const stringify = build({
-    title: 'check array coerce',
-    type: 'object',
-    properties: {},
-    patternProperties: {
-      foo: {
-        type: 'strangetype'
-      }
-    }
-  })
-
-  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { tyrion: 'lannister' } }
-  try {
-    stringify(obj)
-    t.fail()
-  } catch (e) {
-    t.pass()
-  }
-})
diff --git a/test/basic.test.js b/test/basic.test.js
new file mode 100644
index 00000000..355526ab
--- /dev/null
+++ b/test/basic.test.js
@@ -0,0 +1,207 @@
+'use strict'
+
+const test = require('tap').test
+const validator = require('is-my-json-valid')
+const build = require('..')
+
+function buildTest (schema, toStringify) {
+  test(`render a ${schema.title} as JSON`, (t) => {
+    t.plan(3)
+
+    const validate = validator(schema)
+    const stringify = build(schema)
+    const output = stringify(toStringify)
+
+    t.deepEqual(JSON.parse(output), toStringify)
+    t.equal(output, JSON.stringify(toStringify))
+    t.ok(validate(JSON.parse(output)), 'valid schema')
+  })
+}
+
+buildTest({
+  'title': 'basic',
+  'type': 'object',
+  'properties': {
+    'firstName': {
+      'type': 'string'
+    },
+    'lastName': {
+      'type': 'string'
+    },
+    'age': {
+      'description': 'Age in years',
+      'type': 'integer',
+      'minimum': 0
+    },
+    'magic': {
+      'type': 'number'
+    }
+  },
+  'required': ['firstName', 'lastName']
+}, {
+  firstName: 'Matteo',
+  lastName: 'Collina',
+  age: 32,
+  magic: 42.42
+})
+
+buildTest({
+  title: 'string',
+  type: 'string'
+}, 'hello world')
+
+buildTest({
+  title: 'string with quotes',
+  type: 'string'
+}, 'hello """" world')
+
+buildTest({
+  title: 'boolean true',
+  type: 'boolean'
+}, true)
+
+buildTest({
+  title: 'boolean false',
+  type: 'boolean'
+}, false)
+
+buildTest({
+  title: 'an integer',
+  type: 'integer'
+}, 42)
+
+buildTest({
+  title: 'a number',
+  type: 'number'
+}, 42.42)
+
+buildTest({
+  'title': 'deep',
+  'type': 'object',
+  'properties': {
+    'firstName': {
+      'type': 'string'
+    },
+    'lastName': {
+      'type': 'string'
+    },
+    'more': {
+      'description': 'more properties',
+      'type': 'object',
+      'properties': {
+        'something': {
+          'type': 'string'
+        }
+      }
+    }
+  }
+}, {
+  firstName: 'Matteo',
+  lastName: 'Collina',
+  more: {
+    something: 'else'
+  }
+})
+
+buildTest({
+  'title': 'null',
+  'type': 'null'
+}, null)
+
+buildTest({
+  'title': 'with null',
+  'type': 'object',
+  'properties': {
+    'firstName': {
+      'type': 'null'
+    }
+  }
+}, {
+  firstName: null
+})
+
+buildTest({
+  'title': 'array with objects',
+  'type': 'array',
+  'items': {
+    'type': 'object',
+    'properties': {
+      'name': {
+        'type': 'string'
+      }
+    }
+  }
+}, [{
+  name: 'Matteo'
+}, {
+  name: 'Dave'
+}])
+
+buildTest({
+  'title': 'array with strings',
+  'type': 'array',
+  'items': {
+    'type': 'string'
+  }
+}, [
+  'Matteo',
+  'Dave'
+])
+
+buildTest({
+  'title': 'array with numbers',
+  'type': 'array',
+  'items': {
+    'type': 'number'
+  }
+}, [
+  42.42,
+  24
+])
+
+buildTest({
+  'title': 'array with integers',
+  'type': 'array',
+  'items': {
+    'type': 'number'
+  }
+}, [
+  42,
+  24
+])
+
+buildTest({
+  'title': 'nested array with objects',
+  'type': 'object',
+  'properties': {
+    'data': {
+      'type': 'array',
+      'items': {
+        'type': 'object',
+        'properties': {
+          'name': {
+            'type': 'string'
+          }
+        }
+      }
+    }
+  }
+}, {
+  data: [{
+    name: 'Matteo'
+  }, {
+    name: 'Dave'
+  }]
+})
+
+buildTest({
+  'title': 'object with boolean',
+  'type': 'object',
+  'properties': {
+    'readonly': {
+      'type': 'boolean'
+    }
+  }
+}, {
+  readonly: true
+})
diff --git a/test/date.test.js b/test/date.test.js
new file mode 100644
index 00000000..8f0a823c
--- /dev/null
+++ b/test/date.test.js
@@ -0,0 +1,22 @@
+'use strict'
+
+const test = require('tap').test
+const validator = require('is-my-json-valid')
+const build = require('..')
+
+test('render a a date in a string as JSON', (t) => {
+  t.plan(2)
+
+  const schema = {
+    title: 'a date in a string',
+    type: 'string'
+  }
+  const toStringify = new Date()
+
+  const validate = validator(schema)
+  const stringify = build(schema)
+  const output = stringify(toStringify)
+
+  t.equal(output, JSON.stringify(toStringify))
+  t.ok(validate(JSON.parse(output)), 'valid schema')
+})
diff --git a/test/missing-values.test.js b/test/missing-values.test.js
new file mode 100644
index 00000000..6ac8029e
--- /dev/null
+++ b/test/missing-values.test.js
@@ -0,0 +1,28 @@
+'use strict'
+
+const test = require('tap').test
+const build = require('..')
+
+test('missing values', (t) => {
+  t.plan(3)
+
+  const stringify = build({
+    title: 'object with missing values',
+    type: 'object',
+    properties: {
+      str: {
+        type: 'string'
+      },
+      num: {
+        type: 'number'
+      },
+      val: {
+        type: 'string'
+      }
+    }
+  })
+
+  t.equal('{"val":"value"}', stringify({ val: 'value' }))
+  t.equal('{"str":"string","val":"value"}', stringify({ str: 'string', val: 'value' }))
+  t.equal('{"str":"string","num":42,"val":"value"}', stringify({ str: 'string', num: 42, val: 'value' }))
+})
diff --git a/test/patternProperties.test.js b/test/patternProperties.test.js
new file mode 100644
index 00000000..0f56d5e3
--- /dev/null
+++ b/test/patternProperties.test.js
@@ -0,0 +1,161 @@
+'use strict'
+
+const test = require('tap').test
+const build = require('..')
+
+test('patternProperties', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'patternProperties',
+    type: 'object',
+    properties: {
+      str: {
+        type: 'string'
+      }
+    },
+    patternProperties: {
+      'foo': {
+        type: 'string'
+      }
+    }
+  })
+
+  let obj = { str: 'test', foo: 42, ofoo: true, foof: 'string', objfoo: {a: true}, notMe: false }
+  t.equal('{"foo":"42","ofoo":"true","foof":"string","objfoo":"[object Object]","str":"test"}', stringify(obj))
+})
+
+test('patternProperties should not change properties', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'patternProperties should not change properties',
+    type: 'object',
+    properties: {
+      foo: {
+        type: 'string'
+      }
+    },
+    patternProperties: {
+      foo: {
+        type: 'number'
+      }
+    }
+  })
+
+  const obj = { foo: '42', ofoo: 42 }
+  t.equal('{"ofoo":42,"foo":"42"}', stringify(obj))
+})
+
+test('patternProperties - string coerce', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check string coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'string'
+      }
+    }
+  })
+
+  const obj = { foo: true, ofoo: 42, arrfoo: ['array', 'test'], objfoo: { a: 'world' } }
+  t.equal('{"foo":"true","ofoo":"42","arrfoo":"array,test","objfoo":"[object Object]"}', stringify(obj))
+})
+
+test('patternProperties - number coerce', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check number coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'number'
+      }
+    }
+  })
+
+  const obj = { foo: true, ofoo: '42', xfoo: 'string', arrfoo: [1, 2], objfoo: { num: 42 } }
+  t.equal('{"foo":1,"ofoo":42,"xfoo":null,"arrfoo":null,"objfoo":null}', stringify(obj))
+})
+
+test('patternProperties - boolean coerce', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check boolean coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'boolean'
+      }
+    }
+  })
+
+  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { a: true } }
+  t.equal('{"foo":true,"ofoo":false,"arrfoo":true,"objfoo":true}', stringify(obj))
+})
+
+test('patternProperties - object coerce', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check object coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'object',
+        properties: {
+          answer: {
+            type: 'number'
+          }
+        }
+      }
+    }
+  })
+
+  const obj = { objfoo: { answer: 42 } }
+  t.equal('{"objfoo":{"answer":42}}', stringify(obj))
+})
+
+test('patternProperties - array coerce', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check array coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'array',
+        items: {
+          type: 'string'
+        }
+      }
+    }
+  })
+
+  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { tyrion: 'lannister' } }
+  t.equal('{"foo":["t","r","u","e"],"ofoo":[],"arrfoo":["1","2"],"objfoo":[]}', stringify(obj))
+})
+
+test('patternProperties - throw on unknown type', (t) => {
+  t.plan(1)
+  const stringify = build({
+    title: 'check array coerce',
+    type: 'object',
+    properties: {},
+    patternProperties: {
+      foo: {
+        type: 'strangetype'
+      }
+    }
+  })
+
+  const obj = { foo: 'true', ofoo: 0, arrfoo: [1, 2], objfoo: { tyrion: 'lannister' } }
+  try {
+    stringify(obj)
+    t.fail()
+  } catch (e) {
+    t.pass()
+  }
+})
diff --git a/test/regex.test.js b/test/regex.test.js
new file mode 100644
index 00000000..18471c2d
--- /dev/null
+++ b/test/regex.test.js
@@ -0,0 +1,37 @@
+'use strict'
+
+const test = require('tap').test
+const validator = require('is-my-json-valid')
+const build = require('..')
+
+test('object with RexExp', (t) => {
+  t.plan(3)
+
+  const schema = {
+    title: 'object with RegExp',
+    type: 'object',
+    properties: {
+      reg: {
+        type: 'string'
+      }
+    }
+  }
+
+  const obj = {
+    reg: /"([^"]|\\")*"/
+  }
+
+  const stringify = build(schema)
+  const validate = validator(schema)
+  const output = stringify(obj)
+
+  try {
+    JSON.parse(output)
+    t.pass()
+  } catch (e) {
+    t.fail()
+  }
+
+  t.equal(obj.reg.source, new RegExp(JSON.parse(output).reg).source)
+  t.ok(validate(JSON.parse(output)), 'valid schema')
+})
diff --git a/test/required.test.js b/test/required.test.js
new file mode 100644
index 00000000..2b97bcbb
--- /dev/null
+++ b/test/required.test.js
@@ -0,0 +1,42 @@
+'use strict'
+
+const test = require('tap').test
+const build = require('..')
+
+test('object with required field', (t) => {
+  t.plan(3)
+
+  const schema = {
+    title: 'object with required field',
+    type: 'object',
+    properties: {
+      str: {
+        type: 'string'
+      },
+      num: {
+        type: 'integer'
+      }
+    },
+    required: ['str']
+  }
+  const stringify = build(schema)
+
+  try {
+    stringify({
+      str: 'string'
+    })
+    t.pass()
+  } catch (e) {
+    t.fail()
+  }
+
+  try {
+    stringify({
+      num: 42
+    })
+    t.fail()
+  } catch (e) {
+    t.is(e.message, 'str is required!')
+    t.pass()
+  }
+})