[Repo Assist] Add DateOnly/TimeOnly inference support (closes #1461)

src/FSharp.Data.Csv.Core/CsvInference.fs

@@ -32,7 +32,14 @@ let private nameToTypeForCsv =
         "datetimeoffset option", (typeof<DateTimeOffset>, TypeWrapper.Option)
         "timespan option", (typeof<TimeSpan>, TypeWrapper.Option)
         "guid option", (typeof<Guid>, TypeWrapper.Option)
-        "string option", (typeof<string>, TypeWrapper.Option) ]
+        "string option", (typeof<string>, TypeWrapper.Option)
+#if NET6_0_OR_GREATER
+        "dateonly?", (typeof<DateOnly>, TypeWrapper.Nullable)
+        "timeonly?", (typeof<TimeOnly>, TypeWrapper.Nullable)
+        "dateonly option", (typeof<DateOnly>, TypeWrapper.Option)
+        "timeonly option", (typeof<TimeOnly>, TypeWrapper.Option)
+#endif
+        ]
     |> dict
 
 let private nameAndTypeRegex =

src/FSharp.Data.Csv.Core/FSharp.Data.Csv.Core.fsproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <OtherFlags>$(OtherFlags) --warnon:1182 --nowarn:10001 --nowarn:44</OtherFlags>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>

src/FSharp.Data.DesignTime/CommonProviderImplementation/ConversionsGenerator.fs

@@ -32,6 +32,12 @@ let getConversionQuotation missingValuesStr cultureStr typ (value: Expr<string o
         <@@ TextRuntime.ConvertDateTimeOffset(cultureStr, %value) @@>
     elif typ = typeof<TimeSpan> then
         <@@ TextRuntime.ConvertTimeSpan(cultureStr, %value) @@>
+#if NET6_0_OR_GREATER
+    elif typ = typeof<DateOnly> then
+        <@@ TextRuntime.ConvertDateOnly(cultureStr, %value) @@>
+    elif typ = typeof<TimeOnly> then
+        <@@ TextRuntime.ConvertTimeOnly(cultureStr, %value) @@>
+#endif
     elif typ = typeof<Guid> then
         <@@ TextRuntime.ConvertGuid(%value) @@>
     else
@@ -58,6 +64,12 @@ let getBackConversionQuotation missingValuesStr cultureStr typ value : Expr<stri
         <@ TextRuntime.ConvertDateTimeOffsetBack(cultureStr, %%value) @>
     elif typ = typeof<TimeSpan> then
         <@ TextRuntime.ConvertTimeSpanBack(cultureStr, %%value) @>
+#if NET6_0_OR_GREATER
+    elif typ = typeof<DateOnly> then
+        <@ TextRuntime.ConvertDateOnlyBack(cultureStr, %%value) @>
+    elif typ = typeof<TimeOnly> then
+        <@ TextRuntime.ConvertTimeOnlyBack(cultureStr, %%value) @>
+#endif
     else
         failwith "getBackConversionQuotation: Unsupported primitive type"
 

src/FSharp.Data.DesignTime/FSharp.Data.DesignTime.fsproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <IsPackable>false</IsPackable>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <DefineConstants>IS_DESIGNTIME;NO_GENERATIVE;$(DefineConstants)</DefineConstants>
     <OtherFlags>$(OtherFlags) --warnon:1182 --nowarn:44</OtherFlags>
     <GenerateDocumentationFile>false</GenerateDocumentationFile>

src/FSharp.Data.DesignTime/Json/JsonConversionsGenerator.fs

@@ -34,6 +34,12 @@ let getConversionQuotation missingValuesStr cultureStr typ (value: Expr<JsonValu
         <@@ JsonRuntime.ConvertDateTime(cultureStr, %value) @@>
     elif typ = typeof<TimeSpan> then
         <@@ JsonRuntime.ConvertTimeSpan(cultureStr, %value) @@>
+#if NET6_0_OR_GREATER
+    elif typ = typeof<DateOnly> then
+        <@@ JsonRuntime.ConvertDateOnly(cultureStr, %value) @@>
+    elif typ = typeof<TimeOnly> then
+        <@@ JsonRuntime.ConvertTimeOnly(cultureStr, %value) @@>
+#endif
     elif typ = typeof<Guid> then
         <@@ JsonRuntime.ConvertGuid(%value) @@>
     else

src/FSharp.Data.Json.Core/FSharp.Data.Json.Core.fsproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <OtherFlags>$(OtherFlags) --warnon:1182 --nowarn:10001 --nowarn:44</OtherFlags>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>

src/FSharp.Data.Json.Core/JsonConversions.fs

@@ -85,6 +85,18 @@ type JsonConversions =
         | JsonValue.String s -> TextConversions.AsTimeSpan cultureInfo s
         | _ -> None
 
+#if NET6_0_OR_GREATER
+    static member AsDateOnly cultureInfo =
+        function
+        | JsonValue.String s -> TextConversions.AsDateOnly cultureInfo s
+        | _ -> None
+
+    static member AsTimeOnly cultureInfo =
+        function
+        | JsonValue.String s -> TextConversions.AsTimeOnly cultureInfo s
+        | _ -> None
+#endif
+
     static member AsGuid =
         function
         | JsonValue.String s -> TextConversions.AsGuid s

src/FSharp.Data.Json.Core/JsonRuntime.fs

@@ -62,6 +62,16 @@ type JsonRuntime =
         json
         |> Option.bind (JsonConversions.AsTimeSpan(TextRuntime.GetCulture cultureStr))
 
+#if NET6_0_OR_GREATER
+    static member ConvertDateOnly(cultureStr, json) =
+        json
+        |> Option.bind (JsonConversions.AsDateOnly(TextRuntime.GetCulture cultureStr))
+
+    static member ConvertTimeOnly(cultureStr, json) =
+        json
+        |> Option.bind (JsonConversions.AsTimeOnly(TextRuntime.GetCulture cultureStr))
+#endif
+
     static member ConvertGuid(json) =
         json |> Option.bind JsonConversions.AsGuid
 
@@ -229,6 +239,10 @@ type JsonRuntime =
             fun json -> (JsonConversions.AsDateTimeOffset cultureInfo json).IsSome
         | InferedTypeTag.TimeSpan -> JsonConversions.AsTimeSpan(TextRuntime.GetCulture cultureStr) >> Option.isSome
         | InferedTypeTag.Guid -> JsonConversions.AsGuid >> Option.isSome
+#if NET6_0_OR_GREATER
+        | InferedTypeTag.DateOnly -> JsonConversions.AsDateOnly(TextRuntime.GetCulture cultureStr) >> Option.isSome
+        | InferedTypeTag.TimeOnly -> JsonConversions.AsTimeOnly(TextRuntime.GetCulture cultureStr) >> Option.isSome
+#endif
         | InferedTypeTag.Collection ->
             function
             | JsonValue.Array _ -> true

src/FSharp.Data.Runtime.Utilities/FSharp.Data.Runtime.Utilities.fsproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <OtherFlags>$(OtherFlags) --warnon:1182 --nowarn:10001 --nowarn:44</OtherFlags>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>

src/FSharp.Data.Runtime.Utilities/IO.fs

@@ -133,7 +133,7 @@ let internal logTime (_: string) (_: string) = dummyDisposable
 
 #endif
 
-type private FileWatcher(path) =
+type private FileWatcher(path: string) =
 
     let subscriptions = Dictionary<string, unit -> unit>()
 

src/FSharp.Data.Runtime.Utilities/StructuralInference.fs

@@ -82,6 +82,9 @@ let private primitiveTypes =
       typeof<bool>
       typeof<Bit> ]
     @ numericTypes
+#if NET6_0_OR_GREATER
+    @ [ typeof<DateOnly>; typeof<TimeOnly> ]
+#endif
 
 /// Checks whether a type supports unit of measure
 [<Obsolete("This API will be made internal in a future release. Please file an issue at https://github.com/fsprojects/FSharp.Data/issues/1458 if you need this public.")>]
@@ -110,6 +113,12 @@ let typeTag inferredType =
             InferedTypeTag.TimeSpan
         elif typ = typeof<Guid> then
             InferedTypeTag.Guid
+#if NET6_0_OR_GREATER
+        elif typ = typeof<DateOnly> then
+            InferedTypeTag.DateOnly
+        elif typ = typeof<TimeOnly> then
+            InferedTypeTag.TimeOnly
+#endif
         else
             failwith "typeTag: Unknown primitive type"
     | InferedType.Json _ -> InferedTypeTag.Json
@@ -138,7 +147,16 @@ let private conversionTable =
         typeof<int>
         typeof<int64>
         typeof<decimal> ]
-      typeof<DateTime>, [ typeof<DateTimeOffset> ] ]
+      typeof<DateTime>,
+      [ typeof<DateTimeOffset>
+#if NET6_0_OR_GREATER
+        typeof<DateOnly>
+#endif
+        ]
+#if NET6_0_OR_GREATER
+      typeof<TimeSpan>, [ typeof<TimeOnly> ]
+#endif
+      ]
 
 let private subtypePrimitives typ1 typ2 =
     Debug.Assert(List.exists ((=) typ1) primitiveTypes)
@@ -425,7 +443,12 @@ let nameToType =
       "datetimeoffset", (typeof<DateTimeOffset>, TypeWrapper.None)
       "timespan", (typeof<TimeSpan>, TypeWrapper.None)
       "guid", (typeof<Guid>, TypeWrapper.None)
-      "string", (typeof<String>, TypeWrapper.None) ]
+      "string", (typeof<String>, TypeWrapper.None)
+#if NET6_0_OR_GREATER
+      "dateonly", (typeof<DateOnly>, TypeWrapper.None)
+      "timeonly", (typeof<TimeOnly>, TypeWrapper.None)
+#endif
+      ]
     |> dict
 
 // type<unit} or type{unit> is valid while it shouldn't, but well...
@@ -545,6 +568,10 @@ let inferPrimitiveType
         | Parse TextConversions.AsTimeSpan _ -> makePrimitive typeof<TimeSpan>
         | Parse TextConversions.AsDateTimeOffset dateTimeOffset when not (isFakeDate dateTimeOffset.UtcDateTime value) ->
             makePrimitive typeof<DateTimeOffset>
+#if NET6_0_OR_GREATER
+        | Parse TextConversions.AsDateOnly dateOnly when not (isFakeDate (dateOnly.ToDateTime(TimeOnly.MinValue)) value) ->
+            makePrimitive typeof<DateOnly>
+#endif
         | Parse TextConversions.AsDateTime date when not (isFakeDate date value) -> makePrimitive typeof<DateTime>
         | Parse TextConversions.AsDecimal _ -> makePrimitive typeof<decimal>
         | Parse (TextConversions.AsFloat [||] false) _ -> makePrimitive typeof<float>

src/FSharp.Data.Runtime.Utilities/StructuralTypes.fs

@@ -45,6 +45,10 @@ type InferedTypeTag =
     | TimeSpan
     | DateTimeOffset
     | Guid
+#if NET6_0_OR_GREATER
+    | DateOnly
+    | TimeOnly
+#endif
     // Collections and sum types
     | Collection
     | Heterogeneous
@@ -160,6 +164,10 @@ type internal InferedTypeTag with
         | Record None -> "Record"
         | Record(Some name) -> NameUtils.nicePascalName name
         | Json -> "Json"
+#if NET6_0_OR_GREATER
+        | DateOnly -> "DateOnly"
+        | TimeOnly -> "TimeOnly"
+#endif
 
     /// Converts tag to string code that can be passed to generated code
     member x.Code =
@@ -182,6 +190,10 @@ type internal InferedTypeTag with
         | "Guid" -> Guid
         | "Array" -> Collection
         | "Choice" -> Heterogeneous
+#if NET6_0_OR_GREATER
+        | "DateOnly" -> DateOnly
+        | "TimeOnly" -> TimeOnly
+#endif
         | "Null" -> failwith "Null nodes should be skipped"
         | _ -> failwith "Invalid InferredTypeTag code"
 

src/FSharp.Data.Runtime.Utilities/TextConversions.fs

@@ -41,7 +41,7 @@ module private Helpers =
     let dateTimeStyles =
         DateTimeStyles.AllowWhiteSpaces ||| DateTimeStyles.RoundtripKind
 
-    let ParseISO8601FormattedDateTime text cultureInfo =
+    let ParseISO8601FormattedDateTime (text: string) cultureInfo =
         match DateTime.TryParse(text, cultureInfo, dateTimeStyles) with
         | true, d -> d |> ValueSome
         | false, _ -> ValueNone
@@ -174,7 +174,7 @@ type TextConversions private () =
             let min = (hourMin % 100) |> float |> TimeSpan.FromMinutes
             hr.Add min
 
-        let offset str =
+        let offset (str: string) =
             match Int32.TryParse str with
             | true, v -> getTimeSpanFromHourMin v |> ValueSome
             | false, _ -> ValueNone
@@ -208,6 +208,32 @@ type TextConversions private () =
         | true, t -> Some t
         | _ -> None
 
+#if NET6_0_OR_GREATER
+    static member AsDateOnly (cultureInfo: CultureInfo) (text: string) =
+        let mutable d = DateOnly.MinValue
+
+        if DateOnly.TryParse(text.Trim(), cultureInfo, Globalization.DateTimeStyles.AllowWhiteSpaces, &d) then
+            // Reject strings that also parse as DateTime with a non-zero time component,
+            // e.g. "2022-06-12T01:02:03" should be DateTime, not DateOnly.
+            match DateTime.TryParse(text.Trim(), cultureInfo, Globalization.DateTimeStyles.AllowWhiteSpaces) with
+            | true, dt when dt.TimeOfDay <> TimeSpan.Zero -> None
+            | _ -> Some d
+        else
+            None
+
+    static member AsTimeOnly (cultureInfo: CultureInfo) (text: string) =
+        let mutable t = TimeOnly.MinValue
+
+        if TimeOnly.TryParse(text.Trim(), cultureInfo, Globalization.DateTimeStyles.AllowWhiteSpaces, &t) then
+            // Reject strings that also parse as DateTime with a specific real date
+            // (not today's date used as fill-in), e.g. "2016-10-05T04:05:03" is DateTime, not TimeOnly.
+            match DateTime.TryParse(text.Trim(), cultureInfo, Globalization.DateTimeStyles.AllowWhiteSpaces) with
+            | true, dt when dt.Date <> DateTime.Today -> None
+            | _ -> Some t
+        else
+            None
+#endif
+
     static member AsGuid(text: string) = Guid.TryParse(text.Trim()) |> asOption
 
 module internal UnicodeHelper =

src/FSharp.Data.Runtime.Utilities/TextRuntime.fs

@@ -78,6 +78,16 @@ type TextRuntime =
         text
         |> Option.bind (TextConversions.AsTimeSpan(TextRuntime.GetCulture cultureStr))
 
+#if NET6_0_OR_GREATER
+    static member ConvertDateOnly(cultureStr, text) =
+        text
+        |> Option.bind (TextConversions.AsDateOnly(TextRuntime.GetCulture cultureStr))
+
+    static member ConvertTimeOnly(cultureStr, text) =
+        text
+        |> Option.bind (TextConversions.AsTimeOnly(TextRuntime.GetCulture cultureStr))
+#endif
+
     static member ConvertGuid(text) =
         text |> Option.bind TextConversions.AsGuid
 
@@ -136,6 +146,18 @@ type TextRuntime =
         | Some value -> value.ToString("g", TextRuntime.GetCulture cultureStr)
         | None -> ""
 
+#if NET6_0_OR_GREATER
+    static member ConvertDateOnlyBack(cultureStr, value: DateOnly option) =
+        match value with
+        | Some value -> value.ToString("O", TextRuntime.GetCulture cultureStr)
+        | None -> ""
+
+    static member ConvertTimeOnlyBack(cultureStr, value: TimeOnly option) =
+        match value with
+        | Some value -> value.ToString("O", TextRuntime.GetCulture cultureStr)
+        | None -> ""
+#endif
+
     static member ConvertGuidBack(value: Guid option) =
         match value with
         | Some value -> value.ToString()

src/FSharp.Data/FSharp.Data.fsproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net8.0</TargetFrameworks>
     <OtherFlags>$(OtherFlags) --warnon:1182 --nowarn:10001</OtherFlags>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>

tests/FSharp.Data.Core.Tests/TextConversions.fs

@@ -209,6 +209,33 @@ let ``TimeSpan conversions``() =
   TextConversions.AsTimeSpan culture "invalid:00:00" |> should equal None
   TextConversions.AsTimeSpan culture "" |> should equal None
 
+#if NET6_0_OR_GREATER
+[<Test>]
+let ``DateOnly conversions`` () =
+  let culture = CultureInfo.InvariantCulture
+
+  TextConversions.AsDateOnly culture "2023-01-15" |> should equal (Some (DateOnly(2023, 1, 15)))
+  TextConversions.AsDateOnly culture "2000-12-31" |> should equal (Some (DateOnly(2000, 12, 31)))
+
+  // A datetime string should NOT match (DateOnly can't parse time components)
+  TextConversions.AsDateOnly culture "2023-01-15T10:30:00" |> should equal None
+  TextConversions.AsDateOnly culture "invalid" |> should equal None
+  TextConversions.AsDateOnly culture "" |> should equal None
+
+[<Test>]
+let ``TimeOnly conversions`` () =
+  let culture = CultureInfo.InvariantCulture
+
+  TextConversions.AsTimeOnly culture "10:30:45" |> should equal (Some (TimeOnly(10, 30, 45)))
+  TextConversions.AsTimeOnly culture "00:00:00" |> should equal (Some TimeOnly.MinValue)
+  TextConversions.AsTimeOnly culture "23:59:59" |> should equal (Some (TimeOnly(23, 59, 59)))
+
+  // A date string should NOT match
+  TextConversions.AsTimeOnly culture "2023-01-15" |> should equal None
+  TextConversions.AsTimeOnly culture "invalid" |> should equal None
+  TextConversions.AsTimeOnly culture "" |> should equal None
+#endif
+
 [<Test>]
 let ``Guid conversions``() = 
   let validGuid = Guid.NewGuid()