recheck runs once passes

resolves #7

src/Hedgehog.Xunit/Exceptions.fs

@@ -0,0 +1,7 @@
+namespace Hedgehog.Xunit
+
+// This exists to make it clear to users that the exception is in the return of their test.
+// Raising System.Exception isn't descriptive enough.
+// Using Xunit.Assert.True could be confusing since it may resemble a user's assertion.
+type internal TestReturnedFalseException() =
+  inherit System.Exception("Test returned `false`.")

src/Hedgehog.Xunit/Hedgehog.Xunit.fsproj

@@ -33,6 +33,7 @@ Docs at https://github.com/dharmaturtle/fsharp-hedgehog-xunit
   </ItemGroup>
 
   <ItemGroup>
+    <Compile Include="Exceptions.fs" />
     <Compile Include="Attributes.fs" />
     <Compile Include="InternalLogic.fs" />
     <Compile Include="XunitOverrides.fs" />

src/Hedgehog.Xunit/InternalLogic.fs

@@ -90,7 +90,7 @@ open System.Linq
 
 let rec toProperty (x: obj) =
   match x with
-  | :? bool        as b -> Property.ofBool b
+  | :? bool        as b -> if not b then TestReturnedFalseException() |> raise
   | :? Task<unit>  as t -> Async.AwaitTask t |> toProperty
   | _ when x <> null && x.GetType().IsGenericType && x.GetType().GetGenericTypeDefinition().IsSubclassOf typeof<Task> ->
     typeof<Async>
@@ -115,7 +115,7 @@ let rec toProperty (x: obj) =
       .MakeGenericMethod(x.GetType().GetGenericArguments())
       .Invoke(null, [|x|])
     |> toProperty
-  | _                   -> Property.success ()
+  | _                   -> ()
 
 let dispose (o:obj) =
   match o with
@@ -166,7 +166,7 @@ let report (testMethod:MethodInfo) testClass testClassInstance =
     PropertyConfig.defaultConfig
     |> withTests tests
     |> withShrinks shrinks
-  Property.forAll invoke gens
+  PropertyBuilder.property.BindReturn(gens, invoke)
   |> match recheck with
      | Some recheckData -> Property.reportRecheckWith recheckData config
      | None             -> Property.reportWith config

tests/Hedgehog.Xunit.Tests/PropertyTests.fs

@@ -628,7 +628,9 @@ module ``tryRaise tests`` =
     let report = InternalLogic.report (nameof ``always fails, skipped`` |> getMethod) typeof<Marker>.DeclaringType null
     let actual = Assert.Throws<Exception>(fun () -> InternalLogic.tryRaise report)
     let expectedMessage = """*** Failed! Falsifiable (after 1 test):
-[]
+[]"""
+    actual.Message.Contains(expectedMessage) |> Assert.True
+    let expectedMessage = """
 This failure can be reproduced by running:
 > Property.recheck "0_"""
-    actual.Message.StartsWith(expectedMessage) |> Assert.True
+    actual.Message.Contains(expectedMessage) |> Assert.True