Fix maxLength bug

Author: sol

hjsonschema.cabal

@@ -81,6 +81,51 @@ library
     , text                 >= 1.1
     , vector               >= 0.10
 
+test-suite spec
+  hs-source-dirs:
+    test
+    src
+  main-is: Spec.hs
+  type: exitcode-stdio-1.0
+  default-language: Haskell2010
+  ghc-options:
+    -Wall
+  default-extensions:
+    DeriveGeneric
+    NoImplicitPrelude
+    OverloadedStrings
+    ScopedTypeVariables
+  other-modules:
+      Import
+      JSONSchema.Validator.Draft4.String
+
+      JSONSchema.Validator.Draft4.StringSpec
+  build-depends:
+      base                 >= 4.7 && < 5
+    -- 0.11 is for `.:!`:
+    , aeson                >= 0.11
+    , bytestring           >= 0.10
+    , containers           >= 0.5
+    , file-embed           >= 0.0.8
+    , filepath             >= 1.3
+    , hashable             >= 1.2
+    , hjsonpointer         >= 1.1
+    -- 0.4.30 is for parseUrlThrow:
+    , http-client          >= 0.4.30
+    , http-client-tls      >= 0.3
+    , http-types           >= 0.8
+    , pcre-heavy           >= 1.0
+    , profunctors          >= 5.0
+    , protolude            >= 0.1.10
+    , QuickCheck           >= 2.8
+    , safe-exceptions      >= 0.1.6
+    , scientific           >= 0.3
+    , unordered-containers >= 0.2
+    , text                 >= 1.1
+    , vector               >= 0.10
+
+    , hspec                >= 2.2
+
 test-suite local
   hs-source-dirs:
     test

src/JSONSchema/Validator/Draft4/String.hs

@@ -22,10 +22,8 @@ data MaxLengthInvalid
     = MaxLengthInvalid MaxLength Text
     deriving (Eq, Show)
 
--- | The spec requires @"maxLength"@ to be non-negative.
 maxLengthVal :: MaxLength -> Text -> Maybe MaxLengthInvalid
 maxLengthVal a@(MaxLength n) x
-    | n <= 0         = Nothing
     | T.length x > n = Just (MaxLengthInvalid a x)
     | otherwise      = Nothing
 
@@ -45,10 +43,8 @@ data MinLengthInvalid
     = MinLengthInvalid MinLength Text
     deriving (Eq, Show)
 
--- | The spec requires @"minLength"@ to be non-negative.
 minLengthVal :: MinLength -> Text -> Maybe MinLengthInvalid
 minLengthVal a@(MinLength n) x
-    | n <= 0         = Nothing
     | T.length x < n = Just (MinLengthInvalid a x)
     | otherwise      = Nothing
 

test/JSONSchema/Validator/Draft4/StringSpec.hs

@@ -0,0 +1,17 @@
+module JSONSchema.Validator.Draft4.StringSpec (spec) where
+
+import           Protolude
+
+import           Test.Hspec
+
+import           JSONSchema.Validator.Draft4.String
+
+spec :: Spec
+spec = do
+    describe "maxLengthVal" $ do
+        context "with 0" $ do
+            it "accepts the empty string" $ do
+                maxLengthVal (MaxLength 0) "" `shouldBe` Nothing
+
+            it "rejects other strings" $ do
+                maxLengthVal (MaxLength 0) "foo" `shouldBe` Just (MaxLengthInvalid (MaxLength 0) "foo")

test/Spec.hs

@@ -0,0 +1 @@
+{-# OPTIONS_GHC -fforce-recomp -F -pgmF hspec-discover #-}