feat: Comparable, StringId, StringIdConverter

CHANGELOG.md

@@ -9,6 +9,12 @@ The `Unreleased` section name is replaced by the expected version of next releas
 ## [Unreleased]
 
 ### Added
+
+- `StringId, Comparable`: Base types for Strongly Typed Ids with string renditions [#116](https://github.com/jet/FsCodec/pull/116)
+- `NewtonsoftJson.StringIdConverter`: Converter for `StringId` [#116](https://github.com/jet/FsCodec/pull/116)
+- `SystemTextJson.StringIdConverter`: Converter for `StringId` [#116](https://github.com/jet/FsCodec/pull/116)
+- `SystemTextJson.StringIdOrDictionaryKeyConverter`: Converter for `StringId` that enables `Dictionary` values using a `StringId`-derived type as a key to be used as a JSON Object Key [#116](https://github.com/jet/FsCodec/pull/116)
+
 ### Changed
 ### Removed
 ### Fixed

src/FsCodec.NewtonsoftJson/FsCodec.NewtonsoftJson.fsproj

@@ -13,6 +13,7 @@
     <Compile Include="Serdes.fs" />
     <Compile Include="Codec.fs" />
     <Compile Include="VerbatimUtf8Converter.fs" />
+    <Compile Include="StringIdConverter.fs" />
   </ItemGroup>
 
   <ItemGroup>

src/FsCodec.NewtonsoftJson/StringIdConverter.fs

@@ -0,0 +1,8 @@
+namespace FsCodec.NewtonsoftJson
+
+/// <summary>Implements conversion to/from <c>string</c> for a <c>FsCodec.StringId</c>-derived type.</summary>
+[<AbstractClass>]
+type StringIdConverter<'T when 'T :> FsCodec.StringId<'T> >(parse: string -> 'T) =
+    inherit JsonIsomorphism<'T, string>()
+    override _.Pickle value = value.ToString()
+    override _.UnPickle input = parse input

src/FsCodec.SystemTextJson/FsCodec.SystemTextJson.fsproj

@@ -15,6 +15,7 @@
     <Compile Include="Codec.fs" />
     <Compile Include="CodecJsonElement.fs" />
     <Compile Include="Interop.fs" />
+    <Compile Include="StringIdConverter.fs" />
   </ItemGroup>
 
   <ItemGroup>

src/FsCodec.SystemTextJson/StringIdConverter.fs

@@ -0,0 +1,18 @@
+namespace FsCodec.SystemTextJson
+
+/// <summary>Implements conversion to/from <c>string</c> for a <c>FsCodec.StringId</c>-derived type.</summary>
+[<AbstractClass>]
+type StringIdConverter<'T when 'T :> FsCodec.StringId<'T> >(parse: string -> 'T) =
+    inherit System.Text.Json.Serialization.JsonConverter<'T>()
+    override _.Write(writer, value, _options) = value.ToString() |> writer.WriteStringValue
+    override _.Read(reader, _type, _options) = reader.GetString() |> parse
+
+/// <summary>Implements conversion to/from <c>string</c> for a <c>FsCodec.StringId</c>-derived type.<br/>
+/// Opts into use of the underlying token as a valid property name when tth type is used as a Key in a <c>IDictionary</c>.</summary>
+[<AbstractClass>]
+type StringIdOrDictionaryKeyConverter<'T when 'T :> FsCodec.StringId<'T> >(parse: string -> 'T) =
+    inherit System.Text.Json.Serialization.JsonConverter<'T>()
+    override _.Write(writer, value, _options) = value.ToString() |> writer.WriteStringValue
+    override _.WriteAsPropertyName(writer, value, _options) = value.ToString() |> writer.WritePropertyName
+    override _.Read(reader, _type, _options) = reader.GetString() |> parse
+    override _.ReadAsPropertyName(reader, _type, _options) = reader.GetString() |> parse

src/FsCodec/FsCodec.fsproj

@@ -11,6 +11,7 @@
     <Compile Include="StreamName.fs" />
     <Compile Include="Union.fs" />
     <Compile Include="TypeSafeEnum.fs" />
+    <Compile Include="StringId.fs" />
   </ItemGroup>
 
   <ItemGroup>

src/FsCodec/StringId.fs

@@ -0,0 +1,20 @@
+namespace FsCodec
+
+/// Endows any type that inherits this class with standard .NET comparison semantics using a supplied token identifier
+[<AbstractClass>]
+type Comparable<'TComp, 'Token when 'TComp :> Comparable<'TComp, 'Token> and 'Token: comparison>(token: 'Token) =
+    member private _.Token = token
+    override x.Equals y = match y with :? Comparable<'TComp, 'Token> as y -> x.Token = y.Token | _ -> false
+    override _.GetHashCode() = hash token
+    interface System.IComparable with
+        member x.CompareTo y =
+            match y with
+            | :? Comparable<'TComp, 'Token> as y -> compare x.Token y.Token
+            | _ -> invalidArg "y" "invalid comparand"
+
+/// Endows any type that inherits this class with standard .NET comparison semantics using a supplied token identifier
+/// + treats the token as the canonical rendition for `ToString()` purposes
+[<AbstractClass>]
+type StringId<'TComp when 'TComp :> Comparable<'TComp, string>>(token: string) =
+    inherit Comparable<'TComp, string>(token)
+    override _.ToString() = token

tests/FsCodec.SystemTextJson.Tests/FsCodec.SystemTextJson.Tests.fsproj

@@ -42,6 +42,7 @@
     <Compile Include="..\FsCodec.NewtonsoftJson.Tests\SomeNullHandlingTests.fs">
       <Link>SomeNullHandlingTests.fs</Link>
     </Compile>
+    <Compile Include="StringIdTests.fs" />
   </ItemGroup>
 
 </Project>

tests/FsCodec.SystemTextJson.Tests/StringIdTests.fs

@@ -0,0 +1,119 @@
+module FsCodec.SystemTextJson.Tests.StringIdTests
+
+open System.Collections.Generic
+open FsCodec.SystemTextJson
+open Xunit
+open Swensen.Unquote
+
+(* Recommended helper aliases to put in your namespace global to avoid having to open long namespaces  *)
+
+type StjNameAttribute = System.Text.Json.Serialization.JsonPropertyNameAttribute
+type StjIgnoreAttribute = System.Text.Json.Serialization.JsonIgnoreAttribute
+type StjConverterAttribute = System.Text.Json.Serialization.JsonConverterAttribute
+
+module Guid =
+
+    let inline gen () = System.Guid.NewGuid()
+    let inline toStringN (x: System.Guid) = x.ToString "N"
+    let inline parse (x: string) = System.Guid.Parse x
+
+module Bare =
+
+    [<Sealed; AutoSerializable false; StjConverter(typeof<SkuIdConverter>)>]
+    type SkuId(value: System.Guid) =
+        // No JSON Ignore attribute required as read-only property
+        member val Value = value
+    and private SkuIdConverter() =
+        inherit JsonIsomorphism<SkuId, string>()
+        override _.Pickle(value: SkuId) = value.Value |> Guid.toStringN
+        override _.UnPickle input = input |> Guid.parse |> SkuId
+
+    [<Fact>]
+    let comparison () =
+        let g = Guid.gen ()
+        let id1, id2 = SkuId g, SkuId g
+        false =! id1.Equals id2
+        id1 <>! id2
+
+    [<Fact>]
+    let serdes () =
+        let x = Guid.gen () |> SkuId
+        $"\"{Guid.toStringN x.Value}\"" =! Serdes.Default.Serialize x
+        let ser = Serdes.Default.Serialize x
+        $"\"{x.Value}\"" <>! ser // Default render of Guid is not toStringN
+        x.Value =! Serdes.Default.Deserialize<SkuId>(ser).Value
+
+        let d = Dictionary()
+        d.Add(x, "value")
+        raises<System.NotSupportedException> <@ Serdes.Default.Serialize d @>
+
+module StringIdIsomorphism =
+
+    [<Sealed; AutoSerializable false; StjConverter(typeof<SkuIdConverter>)>]
+    type SkuId(value: System.Guid) = inherit FsCodec.StringId<SkuId>(Guid.toStringN value)
+    and private SkuIdConverter() =
+        inherit JsonIsomorphism<SkuId, string>()
+        override _.Pickle(value: SkuId) = value |> string
+        override _.UnPickle input = input |> Guid.parse |> SkuId
+
+    [<Fact>]
+    let comparison () =
+        let g = Guid.gen()
+        let id1, id2 = SkuId g, SkuId g
+        true =! id1.Equals id2
+        id1 =! id2
+
+    [<Fact>]
+    let serdes () =
+        let x = Guid.gen () |> SkuId
+        let ser = Serdes.Default.Serialize x
+        $"\"{x}\"" =! ser
+        x =! Serdes.Default.Deserialize ser
+
+        let d = Dictionary()
+        d.Add(x, "value")
+        raises<System.NotSupportedException> <@ Serdes.Default.Serialize d @>
+
+module StringIdConverter =
+
+    [<Sealed; AutoSerializable false; StjConverter(typeof<SkuIdConverter>)>]
+    type SkuId(value: System.Guid) = inherit FsCodec.StringId<SkuId>(Guid.toStringN value)
+    and private SkuIdConverter() = inherit StringIdConverter<SkuId>(Guid.parse >> SkuId)
+
+    [<Fact>]
+    let comparison () =
+        let g = Guid.gen()
+        let id1, id2 = SkuId g, SkuId g
+        true =! id1.Equals id2
+        id1 =! id2
+
+    [<Fact>]
+    let serdes () =
+        let x = Guid.gen () |> SkuId
+        $"\"{x}\"" =! Serdes.Default.Serialize x
+
+        let d = Dictionary()
+        d.Add(x, "value")
+        raises<System.NotSupportedException> <@ Serdes.Default.Serialize d @>
+
+module StringIdOrKeyConverter =
+
+    [<Sealed; AutoSerializable false; StjConverter(typeof<SkuIdConverter>)>]
+    type SkuId(value: System.Guid) = inherit FsCodec.StringId<SkuId>(Guid.toStringN value)
+    and private SkuIdConverter() = inherit StringIdOrDictionaryKeyConverter<SkuId>(Guid.parse >> SkuId)
+
+    [<Fact>]
+    let comparison () =
+        let g = Guid.gen()
+        let id1, id2 = SkuId g, SkuId g
+        true =! id1.Equals id2
+        id1 =! id2
+
+    [<Fact>]
+    let serdes () =
+        let x = Guid.gen () |> SkuId
+        $"\"{x}\"" =! Serdes.Default.Serialize x
+
+        let d = Dictionary()
+        d.Add(x, "value")
+        $"{{\"{x}\":\"value\"}}" =! Serdes.Default.Serialize d