Regex stringify proposal

README.md

@@ -34,14 +34,18 @@ const stringify = fastJson({
     age: {
       description: 'Age in years',
       type: 'integer'
+    },
+    reg: {
+      type: 'string'
     }
   }
 })
 
 console.log(stringify({
   firstName: 'Matteo',
   lastName: 'Collina',
-  age: 32
+  age: 32,
+  reg: /"([^"]|\\")*"/
 }))
 ```
 
@@ -61,8 +65,15 @@ Supported types:
  * `'boolean'`
  * `'null'`
 
-And nested ones, too.
-`Date` instances are serialized with `toISOString()`.
+And nested ones, too.  
+
+*Specific use cases:*
+
+| Instance   | Serialized as                               |
+| -----------|---------------------------------------------|
+| `Date`     | `string` <small>via `toISOString()`</small> |
+| `RegExp`   | `string`                                    |
+
 
 ## Acknowledgements
 

example.js

@@ -17,6 +17,9 @@ const stringify = fastJson({
     },
     now: {
       type: 'string'
+    },
+    reg: {
+      type: 'string'
     }
   }
 })
@@ -25,5 +28,6 @@ console.log(stringify({
   firstName: 'Matteo',
   lastName: 'Collina',
   age: 32,
-  now: new Date()
+  now: new Date(),
+  reg: /"([^"]|\\")*"/
 }))

index.js

@@ -11,6 +11,7 @@ function build (schema) {
     ${$asNumber.toString()}
     ${$asNull.toString()}
     ${$asBoolean.toString()}
+    ${$asRegExp.toString()}
   `
   var main
 
@@ -68,6 +69,8 @@ function $asBoolean (bool) {
 function $asString (str) {
   if (str instanceof Date) {
     return '"' + str.toISOString() + '"'
+  } else if (str instanceof RegExp) {
+    return $asRegExp(str)
   } else if (typeof str !== 'string') {
     str = str.toString()
   }
@@ -115,6 +118,19 @@ function $asStringSmall (str) {
   return '"' + result + '"'
 }
 
+function $asRegExp (reg) {
+  reg = reg.source
+
+  for (var i = 0, len = reg.length; i < len; i++) {
+    if (reg[i] === '\\' || reg[i] === '"') {
+      reg = reg.substring(0, i) + '\\' + reg.substring(i++)
+      len += 2
+    }
+  }
+
+  return '"' + reg + '"'
+}
+
 function buildObject (schema, code, name) {
   code += `
     function ${name} (obj) {

test.js

@@ -222,3 +222,35 @@ buildTest({
 }, {
   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')
+})