Limit the size of QuickCheck-generated patterns.

See #259.

doctest.cabal

@@ -1,10 +1,10 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.32.0.
+-- This file has been generated from package.yaml by hpack version 0.33.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: c49494d6a77aec3f741c557db5db5fecb5c705acb3a4d36aad26c6b77921946f
+-- hash: 53ffc034338153cc76d198a3ba3f05173f47d8bfe1c186f319401ec35e58446a
 
 name:           doctest
 version:        0.16.2
@@ -241,6 +241,7 @@ test-suite spec
     , ghc >=7.0 && <8.11
     , ghc-paths >=0.1.0.9
     , hspec >=2.3.0
+    , hspec-core >=2.3.0
     , mockery
     , process
     , setenv

package.yaml

@@ -65,6 +65,7 @@ tests:
     dependencies:
     - HUnit
     - hspec         >= 2.3.0
+    - hspec-core    >= 2.3.0
     - QuickCheck    >= 2.13.1
     - stringbuilder >= 0.4
     - silently      >= 1.2.4

test/Runner/ExampleSpec.hs

@@ -6,6 +6,7 @@ import           Prelude.Compat
 
 import           Data.String
 import           Test.Hspec
+import           Test.Hspec.Core.QuickCheck (modifyMaxSize)
 import           Test.QuickCheck
 
 import           Parse
@@ -59,9 +60,11 @@ spec = do
         mkResult ["foo", WildCardLine, "bar"] ["foo", "baz", "bazoom", "bar"]
             `shouldBe` Equal
 
-      it "matches an arbitrary number of lines (quickcheck)" $ do
-        property $ \xs -> mkResult (lineToExpected xs) (lineToActual xs)
-            `shouldBe` Equal
+      -- See https://github.com/sol/doctest/issues/259
+      modifyMaxSize (const 8) $
+        it "matches an arbitrary number of lines (quickcheck)" $ do
+          property $ \xs -> mkResult (lineToExpected xs) (lineToActual xs)
+              `shouldBe` Equal
 
     context "with WildCardChunk" $ do
       it "matches an arbitrary line chunk" $ do