Merge pull request hedgehogqa#165 from jwChung/address-datetime-inclu…

…ding-sub-seconds Address generating datetime to include sub seconds
marklam · Jul 13, 2018 · 5f14a9c · 5f14a9c
2 parents f13fa4d + aeec579
commit 5f14a9c
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Showing 2 changed files with 42 additions and 17 deletions.
diff --git a/src/Hedgehog/Gen.fs b/src/Hedgehog/Gen.fs
@@ -496,23 +496,16 @@ module Gen =
     /// Generates a random instant in time expressed as a date and time of day.
     [<CompiledName("DateTime")>]
     let dateTime : Gen<System.DateTime> =
-        let yMin = System.DateTime.MinValue.Year
-        let yMax = System.DateTime.MaxValue.Year
+        let minTicks =
+            System.DateTime.MinValue.Ticks
+        let maxTicks =
+            System.DateTime.MaxValue.Ticks
         gen {
-            let! y =
-                integral <| Range.linearFrom 2000 yMin yMax
-            let! m =
-                integral <| Range.constant 1 12
-            let! d =
-                integral <| Range.constant 1 (System.DateTime.DaysInMonth (y, m))
-            let! h =
-                integral <| Range.constant 0 23
-            let! min =
-                integral <| Range.constant 0 59
-            let! sec =
-                integral <| Range.constant 0 59
-
-            return System.DateTime (y, m, d, h, min, sec)
+            let! ticks =
+                Range.constantFrom
+                    (System.DateTime (2000, 1, 1)).Ticks minTicks maxTicks
+                |> integral
+            return System.DateTime ticks
         }
 
     //

diff --git a/tests/Hedgehog.Tests/GenTests.fs b/tests/Hedgehog.Tests/GenTests.fs
@@ -30,4 +30,36 @@ let ``unicode doesn't return any surrogate`` () =
 let ``unicode doesn't return any noncharacter`` nonchar =
     let isNoncharacter = (=) <| Operators.char nonchar
     let actual = Gen.sample 100 100000 Gen.unicode
-    [] =! List.filter isNoncharacter actual
+    [] =! List.filter isNoncharacter actual
+
+[<Fact>]
+let ``dateTime randomly generates value between max and min ticks`` () =
+    let seed0 = Seed.random()
+    let (seed1, _) = Seed.split seed0
+    let range =
+        Range.constant
+            System.DateTime.MinValue.Ticks
+            System.DateTime.MaxValue.Ticks
+    let ticks =
+        Random.integral range
+        |> Random.run seed1 0
+    let expected = System.DateTime ticks
+
+    let actual = Gen.dateTime
+
+    let result = actual |> Gen.toRandom |> Random.run seed0 0 |> Tree.outcome
+    expected =! result
+
+[<Fact>]
+let ``dateTime shrinks to correct mid-value`` () =
+    let result =
+        property {
+            let! actual = Gen.dateTime
+            System.DateTime.Now =! actual
+        }
+        |> Property.report
+        |> Report.render
+        |> (fun x -> x.Split System.Environment.NewLine)
+        |> Array.item 1
+        |> System.DateTime.Parse
+    System.DateTime (2000, 1, 1) =! result