Merge pull request #480 from njlr/enhancement/issue-426-date-time-kinds

Adds parameter for `DateTimeKind`

Author: moodmosaic

src/Hedgehog.NUnit/GenAttribute.Prelude.fs

@@ -142,8 +142,7 @@ type DateTimeAttribute(kind: DateTimeKind, from: DateTime, duration: TimeSpan) =
     new(from, duration) = DateTimeAttribute(DateTimeKind.Utc, from, duration)
     new(kind) = DateTimeAttribute(kind, DateTime(2000, 1, 1), TimeSpan.FromDays(3650))
     override _.Generator =
-        Gen.dateTime (Range.constant from (from + duration))
-        |> Gen.map (fun x -> DateTime.SpecifyKind(x, kind))
+        Gen.dateTime (Range.constant from (from + duration)) (Gen.constant kind)
 
 /// Generates a DateTimeOffset value.
 type DateTimeOffsetAttribute(from: DateTimeOffset, duration: TimeSpan) =

src/Hedgehog.Xunit/GenAttribute.Prelude.fs

@@ -141,8 +141,7 @@ type DateTimeAttribute(kind: DateTimeKind, from: DateTime, duration: TimeSpan) =
     new(from, duration) = DateTimeAttribute(DateTimeKind.Utc, from, duration)
     new(kind) = DateTimeAttribute(kind, DateTime(2000, 1, 1), TimeSpan.FromDays(3650))
     override _.Generator =
-        Gen.dateTime (Range.constant from (from + duration))
-        |> Gen.map (fun x -> DateTime.SpecifyKind(x, kind))
+        Gen.dateTime (Range.constant from (from + duration)) (Gen.constant kind)
 
 /// Generates a DateTimeOffset value.
 type DateTimeOffsetAttribute(from: DateTimeOffset, duration: TimeSpan) =

src/Hedgehog/Autogen/DefaultGenerators.fs

@@ -33,7 +33,7 @@ type DefaultGenerators =
                 DateTime.MinValue.Ticks
                 DateTime.MaxValue.Ticks
             |> Range.map DateTime
-        Gen.dateTime dateTimeRange |> Gen.map DateTimeOffset
+        Gen.dateTime dateTimeRange (Gen.constant DateTimeKind.Unspecified) |> Gen.map DateTimeOffset
 
     static member ImmutableList<'a>(context: AutoGenContext, valueGen: Gen<'a>) : Gen<ImmutableList<'a>> =
         if context.CanRecurse then

src/Hedgehog/Gen.DateTime.fs

@@ -11,7 +11,18 @@ module GenDateTime =
     module Gen =
 
         /// <summary>
-        /// Generates a random DateTime using the given range.
+        /// Generates a random DateTimeKind uniformly.
+        /// </summary>
+        let dateTimeKind : Gen<DateTimeKind> =
+            Gen.item
+                [|
+                    DateTimeKind.Utc
+                    DateTimeKind.Local
+                    DateTimeKind.Unspecified
+                |]
+
+        /// <summary>
+        /// Generates a random DateTime using the given range and `DateTimeKind` generator.
         /// </summary>
         /// <example>
         /// <code>
@@ -22,12 +33,26 @@ module GenDateTime =
         /// </code>
         /// </example>
         /// <param name="range">Range determining the bounds of the <c>DateTime</c> that can be generated.</param>
-        let dateTime (range : Range<DateTime>) : Gen<DateTime> =
+        /// <param name="kind">Generator determining the <c>DateTimeKind</c>.</param>
+        let dateTime (range : Range<DateTime>) (kind : Gen<DateTimeKind>) : Gen<DateTime> =
             gen {
                 let! ticks = range |> Range.map _.Ticks |> Gen.integral
-                return DateTime ticks
+                and! kind = kind
+                return DateTime(ticks, kind)
             }
 
+        /// Generates a DateTime using the given range with UTC kind.
+        let dateTimeUtc (range : Range<DateTime>) : Gen<DateTime> =
+            dateTime range (Gen.constant DateTimeKind.Utc)
+
+        /// Generates a DateTime using the given range with Local kind.
+        let dateTimeLocal (range : Range<DateTime>) : Gen<DateTime> =
+            dateTime range (Gen.constant DateTimeKind.Local)
+
+        /// Generates a DateTime using the given range with Unspecified kind.
+        let dateTimeUnspecified (range : Range<DateTime>) : Gen<DateTime> =
+            dateTime range (Gen.constant DateTimeKind.Unspecified)
+
         /// Generates a random DateTimeOffset using the given range.
         let dateTimeOffset (range : Range<DateTimeOffset>) : Gen<DateTimeOffset> =
             gen {

src/Hedgehog/Linq/Gen.fs

@@ -299,8 +299,10 @@ type Gen private () =
     /// </code>
     /// </example>
     /// <param name="range">Range determining the bounds of the <c>DateTime</c> that can be generated.</param>
-    static member DateTime (range : Range<DateTime>) : Gen<DateTime> =
-        Gen.dateTime range
+    /// <param name="kind">Generator for the <c>DateTimeKind</c> that can be generated.</param>
+    static member DateTime (range : Range<DateTime>, ?kind) : Gen<DateTime> =
+        let kind = defaultArg kind (Gen.constant DateTimeKind.Unspecified)
+        Gen.dateTime range kind
 
     /// Generates a random DateTimeOffset using the given range.
     static member DateTimeOffset (range : Range<DateTimeOffset>) : Gen<DateTimeOffset> =

tests/Hedgehog.Tests/GenTests.fs

@@ -56,16 +56,17 @@ let genTests = testList "Gen tests" [
         [ 8; 16; 32; 64; 128; 256; 512 ] <| fun count ->
 
         let actual =
-            (Range.constant DateTime.MinValue DateTime.MaxValue)
-            |> Gen.dateTime
+            Gen.dateTime
+                (Range.constant DateTime.MinValue DateTime.MaxValue)
+                (Gen.constant DateTimeKind.Unspecified)
             |> Gen.sample 0 count
             |> Seq.toList
 
         actual
         |> List.distinct
         |> List.length
         =! actual.Length
-        
+
 #if !FABLE_COMPILER
 // See production code
     yield! testCases "timeSpan creates TimeSpan instances"
@@ -97,45 +98,24 @@ let genTests = testList "Gen tests" [
             |> Seq.toList
         [] =! List.filter (fun ch -> ch = char nonchar) actual
 
-    testCase "dateTime randomly generates value between max and min ticks" <| fun _ ->
-        // This is a bad test because essentially the same logic used to
-        // implement Gen.dateTime appears in this test. However, keeping it for
-        // now.
-        let seed = Seed.random ()
-        let range =
-            Range.constant
-                DateTime.MinValue.Ticks
-                DateTime.MaxValue.Ticks
-        let ticks =
-            Random.integral range
-            |> Random.run seed 0
-
-        let actual =
-            Range.constant DateTime.MinValue DateTime.MaxValue
-            |> Gen.dateTime
-            |> Gen.toRandom
-            |> Random.run seed 0
-            |> Tree.outcome
-
-        let expected = DateTime ticks
-        actual =! expected
-
     testCase "dateTime shrinks to correct mid-value" <| fun _ ->
         let generatedValues =
             property {
                 let! actual =
-                  (Range.constantFrom
-                       (DateTime (2000, 1, 1))
-                        DateTime.MinValue
-                        DateTime.MaxValue)
-                  |> Gen.dateTime
+                    Gen.dateTime
+                        (Range.constantFrom
+                            (DateTime (2000, 1, 1))
+                                DateTime.MinValue
+                                DateTime.MaxValue)
+                        (Gen.constant DateTimeKind.Unspecified)
+
                 actual =! DateTime.Now
             }
             |> expectFailureWithGeneratedValues
 
         if List.isEmpty generatedValues then
             failwith "Should have generated values in journal"
-        
+
         let actual = generatedValues.[0] :?> DateTime
         actual =! DateTime (2000, 1, 1)
 
@@ -337,20 +317,20 @@ let genTests = testList "Gen tests" [
         let firstValues = System.Collections.Generic.HashSet<int>()
         let secondValues = System.Collections.Generic.HashSet<int>()
         let thirdValues = System.Collections.Generic.HashSet<int>()
-        
+
         property {
             let! x = Gen.int32 (Range.linear 1 100)
             let! y = Gen.int32 (Range.linear 1 100)
             let! z = Gen.int32 (Range.linear 1 100)
-            
+
             firstValues.Add(x) |> ignore
             secondValues.Add(y) |> ignore
             thirdValues.Add(z) |> ignore
-            
+
             return true
         }
         |> Property.checkBoolWith (PropertyConfig.withTests 100<tests> PropertyConfig.defaults)
-        
+
         // Each generator should produce multiple different values
         // If the seed wasn't threaded properly, they would all produce the same value
         firstValues.Count > 10 |> Expect.isTrue