From 6c22e89b1d07f7977cf05bcc51382c500afb0879 Mon Sep 17 00:00:00 2001
From: Mauricio Scheffer <mauricioscheffer@gmail.com>
Date: Sat, 3 Oct 2020 22:13:55 +0100
Subject: [PATCH] Minor LINQ improvements (#220)

* Test LINQ on Gen

* Support LINQ Select for Range

* Housekeeping

Co-authored-by: Nikos Baxevanis <nikos.baxevanis@gmail.com>
---
 src/Hedgehog/LinqSupport.fs              |  8 ++++++
 tests/Hedgehog.CSharp.Tests/LinqTests.cs | 34 ++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/src/Hedgehog/LinqSupport.fs b/src/Hedgehog/LinqSupport.fs
index 062c7c07..5e653168 100644
--- a/src/Hedgehog/LinqSupport.fs
+++ b/src/Hedgehog/LinqSupport.fs
@@ -62,3 +62,11 @@ module PropertyLinqSupport =
     let bind2Unit (pa : Property<'a>) (f : Func<'a, Property<'b>>) (proj : Action<'a, 'b>) : Property<unit> =
         Property.bind pa (fun a ->
             Property.bind (f.Invoke a) (fun b -> Property.fromThrowing proj.Invoke (a, b)))
+
+[<Extension>]
+module RangeLinqSupport =
+    
+    [<Extension>]
+    [<CompiledName("Select")>]
+    let select (r : Range<'a>) (f : Func<'a, 'b>) : Range<'b> =
+        Range.map (fun x -> f.Invoke x) r
diff --git a/tests/Hedgehog.CSharp.Tests/LinqTests.cs b/tests/Hedgehog.CSharp.Tests/LinqTests.cs
index a7d4909c..5382bd3a 100644
--- a/tests/Hedgehog.CSharp.Tests/LinqTests.cs
+++ b/tests/Hedgehog.CSharp.Tests/LinqTests.cs
@@ -104,5 +104,39 @@ from i in ForAll(Gen.Int32(Range.Constant(1, 10)))
                 from j in ForAll(Gen.Int32(Range.Constant(1, i)))
                 select j <= i);
         }
+        
+        [Fact]
+        public void CanUseSelectWithGen()
+        {
+            Gen<bool> a =
+                from i in Gen.Bool
+                select !i;
+        }
+
+        [Fact]
+        public void CanUseWhereWithGen()
+        {
+            Gen<bool> a =
+                from i in Gen.Bool
+                where i
+                select !i;
+        }
+        
+        [Fact]
+        public void CanUseSelectManyWithGen()
+        {
+            Gen<bool> a =
+                from i in Gen.Bool
+                from j in Gen.Bool
+                select !i;
+        }
+        
+        [Fact]
+        public void CanUseSelectWithRange()
+        {
+            Range<int> a =
+                from i in Range.Constant(1, 10)
+                select i + 10;
+        }
     }
 }