Add generator for JSON values

Author: garyb

bower.json

@@ -1,12 +1,13 @@
 {
   "name": "purescript-argonaut-core",
   "homepage": "https://github.com/purescript-contrib/purescript-argonaut-core",
+  "description": "Core of the purescript-argonaut library, providing basic types, folds, and combinators for `Json`",
+  "license": "MIT",
   "authors": [
     "Maxim Zimaliev <[email protected]>",
     "Hardy Jones <>",
     "John A. De Goes <[email protected]>"
   ],
-  "description": "Core of the purescript-argonaut library, providing basic types, folds, and combinators for `Json`",
   "keywords": [
     "purescript",
     "argonaut",
@@ -16,10 +17,19 @@
     "type": "git",
     "url": "git://github.com/purescript-contrib/purescript-argonaut-core.git"
   },
-  "license": "MIT",
+  "ignore": [
+    "**/.*",
+    "bower_components",
+    "node_modules",
+    "output",
+    "test",
+    "bower.json",
+    "package.json"
+  ],
   "dependencies": {
     "purescript-enums": "^3.0.0",
     "purescript-functions": "^3.0.0",
+    "purescript-gen": "^1.0.0",
     "purescript-maps": "^3.0.0"
   },
   "devDependencies": {

src/Data/Argonaut/Gen.purs

@@ -0,0 +1,57 @@
+module Test.StrongCheck.Data.Argonaut where
+
+import Prelude
+
+import Control.Lazy (class Lazy, defer)
+import Control.Monad.Gen (class MonadGen)
+import Control.Monad.Gen as Gen
+import Control.Monad.Rec.Class (class MonadRec)
+
+import Data.Argonaut.Core as J
+import Data.Array as A
+import Data.Char as C
+import Data.NonEmpty ((:|))
+import Data.String as S
+import Data.StrMap as SM
+
+genJson :: forall m. MonadGen m => MonadRec m => Lazy (m J.Json) => m J.Json
+genJson = Gen.sized genJson'
+  where
+  genJson' :: Int -> m J.Json
+  genJson' size
+    | size > 3 =
+        genJson' 3
+    | size > 0 =
+        Gen.resize (_ - 1) (Gen.choose genJArray genJObject)
+    | otherwise =
+        Gen.oneOf $ pure J.jsonNull :| [ genJBoolean, genJNumber, genJString]
+
+  genJArray :: m J.Json
+  genJArray = J.fromArray <$> Gen.unfoldable (defer \_ -> genJson)
+
+  genJObject :: m J.Json
+  genJObject = A.foldM extendJObj J.jsonEmptyObject =<< Gen.unfoldable genString
+
+  extendJObj :: J.Json -> String -> m J.Json
+  extendJObj obj k = do
+    v <- genJson
+    pure $
+      J.foldJsonObject
+        (J.jsonSingletonObject k v)
+        (J.fromObject <<< SM.insert k v)
+        obj
+
+  genJBoolean :: m J.Json
+  genJBoolean = J.fromBoolean <$> Gen.chooseBool
+
+  genJNumber :: m J.Json
+  genJNumber = J.fromNumber <$> Gen.chooseFloat (-1000000.0) 1000000.0
+
+  genJString :: m J.Json
+  genJString = J.fromString <$> genString
+
+  genString :: m String
+  genString = S.fromCharArray <$> Gen.unfoldable genChar
+
+  genChar :: m Char
+  genChar = C.fromCharCode <$> Gen.chooseInt 0 65535