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TarmilTarmil
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Add CustomDiffer functions
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-26
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4 files changed

+216
-26
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‎src/Diffract/CustomDiffer.fs

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namespace DEdge.Diffract
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open System
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open DEdge.Diffract
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[<Sealed; AbstractClass>]
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type CustomDiffer<'T> =
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="buildDiffFunction">Builds the diff function for this type.</param>
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static member Build(buildDiffFunction: Func<IDifferFactory, Func<'T, 'T, Diff option>>) =
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{ new ICustomDiffer with
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member this.GetCustomDiffer<'U>(differFactory, shape) =
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if shape.Type = typeof<'T> then
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let diffFunction = buildDiffFunction.Invoke(differFactory)
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{ new IDiffer<'T> with
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member _.Diff(x1, x2) = diffFunction.Invoke(x1, x2) }
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|> unbox<IDiffer<'U>>
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|> Some
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else
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None }
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="buildDiffFunction">Builds the diff function for this type.</param>
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static member Build(buildDiffFunction: IDifferFactory -> 'T -> 'T -> Diff option) =
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{ new ICustomDiffer with
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member this.GetCustomDiffer<'U>(differFactory, shape) =
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if shape.Type = typeof<'T> then
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let diffFunction = buildDiffFunction differFactory
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{ new IDiffer<'T> with
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member _.Diff(x1, x2) = diffFunction x1 x2 }
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|> unbox<IDiffer<'U>>
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|> Some
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else
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None }
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="diffFunction">The diff function for this type.</param>
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static member Build(diffFunction: Func<'T, 'T, Diff option>) =
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CustomDiffer.Build(fun _ -> diffFunction)
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/// <summary>
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/// Create a custom differ for a specific type by mapping it to a diffable type.
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/// </summary>
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/// <param name="mapFunction">The mapping function.</param>
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/// <typeparam name="T">The type for which a custom differ is being created.</typeparam>
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/// <typeparam name="U">The type used to actually perform the diff.</typeparam>
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static member Map<'U>(mapFunction: Func<'T, 'U>) =
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CustomDiffer<'T>.Build(fun differFactory ->
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let differ = differFactory.GetDiffer<'U>()
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fun x1 x2 -> differ.Diff(mapFunction.Invoke(x1), mapFunction.Invoke(x2)))
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[<Sealed; AbstractClass>]
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type CustomDiffer =
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="buildDiffFunction">Builds the diff function for this type.</param>
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static member Build(buildDiffFunction: Func<IDifferFactory, Func<'T, 'T, Diff option>>) =
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CustomDiffer<'T>.Build(buildDiffFunction)
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="buildDiffFunction">Builds the diff function for this type.</param>
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static member Build(buildDiffFunction: IDifferFactory -> 'T -> 'T -> Diff option) =
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CustomDiffer<'T>.Build(buildDiffFunction)
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/// <summary>
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/// Create a custom differ for a specific type.
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/// </summary>
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/// <param name="diffFunction">The diff function for this type.</param>
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static member Build(diffFunction: Func<'T, 'T, Diff option>) =
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CustomDiffer<'T>.Build(diffFunction)
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/// <summary>
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/// Create a custom differ for a leaf type using default comparison and a custom display format.
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/// </summary>
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/// <param name="format">The display format.</param>
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static member Leaf<'T when 'T : equality> (format: Func<'T, string>) =
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CustomDiffer.Build<'T>(fun x y ->
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if x = y then
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None
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else
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Diff.Value(format.Invoke(x), format.Invoke(y))
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|> Some)
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/// <summary>
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/// Combine multiple custom differs.
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/// </summary>
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/// <param name="differs">The custom differs.</param>
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static member Combine (differs: seq<ICustomDiffer>) =
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CombinedCustomDiffer(differs) :> ICustomDiffer
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/// <summary>
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/// Combine multiple custom differs.
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/// </summary>
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/// <param name="differs">The custom differs.</param>
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static member Combine ([<ParamArray>] differs: ICustomDiffer[]) =
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CustomDiffer.Combine(differs :> seq<_>)

‎src/Diffract/Diffract.fsproj

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@@ -14,6 +14,7 @@
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</PropertyGroup>
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<ItemGroup>
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<Compile Include="Types.fs" />
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<Compile Include="CustomDiffer.fs" />
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<Compile Include="ReadOnlyDictionaryShape.fs" />
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<Compile Include="DictionaryShape.fs" />
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<Compile Include="Differ.fs" />

‎tests/Diffract.CSharp.Tests/CustomDiffers.cs

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@@ -26,6 +26,36 @@ public void CustomDiffer()
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Assert.Equal(expectedDiff, actualDiff);
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}
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[Fact]
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public void CustomDifferWithCombinators()
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{
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var expectedDiff = "D Expect = \"a\"\n Actual = \"b\"\n";
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var expected = new Container(new CustomDiffable("a"));
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var actual = new Container(new CustomDiffable("b"));
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var actualDiff = MyDifferWithCombinators.Get<Container>().ToString(expected, actual);
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Assert.Equal(expectedDiff, actualDiff);
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}
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[Fact]
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public void CustomDifferWithMap()
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{
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var expectedDiff = "D Expect = \"a\"\n Actual = \"b\"\n";
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var expected = new Container(new CustomDiffable("a"));
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var actual = new Container(new CustomDiffable("b"));
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var actualDiff = MyDifferWithMap.Get<Container>().ToString(expected, actual);
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Assert.Equal(expectedDiff, actualDiff);
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}
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[Fact]
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public void CustomDifferWithMapToAnonymousObject()
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{
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var expectedDiff = "D.v Expect = \"a\"\n Actual = \"b\"\n";
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var expected = new Container(new CustomDiffable("a"));
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var actual = new Container(new CustomDiffable("b"));
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var actualDiff = MyDifferWithMapToAnonymousObject.Get<Container>().ToString(expected, actual);
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Assert.Equal(expectedDiff, actualDiff);
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}
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public record CustomDiffable(string X);
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public record Container(CustomDiffable D);
@@ -57,5 +87,48 @@ public FSharpOption<IDiffer<T>> GetCustomDiffer<T>(IDifferFactory differFactory,
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: null;
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}
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}
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public static class MyDifferWithCombinators
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{
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public static IDiffer<T> Get<T>() => Singleton<T>.Instance;
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private static class Singleton<T>
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{
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public static readonly IDiffer<T> Instance = CustomDiffer.GetDiffer<T>();
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}
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private static readonly ICustomDiffer CustomDiffer =
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CustomDiffer<CustomDiffable>.Build(factory =>
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{
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var stringDiffer = factory.GetDiffer<string>();
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return (x1, x2) => stringDiffer.Diff(x1.X, x2.X);
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});
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}
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public static class MyDifferWithMap
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{
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public static IDiffer<T> Get<T>() => Singleton<T>.Instance;
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private static class Singleton<T>
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{
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public static readonly IDiffer<T> Instance = CustomDiffer.GetDiffer<T>();
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}
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private static readonly ICustomDiffer CustomDiffer =
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CustomDiffer<CustomDiffable>.Map(x => x.X);
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}
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public static class MyDifferWithMapToAnonymousObject
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{
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public static IDiffer<T> Get<T>() => Singleton<T>.Instance;
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private static class Singleton<T>
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{
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public static readonly IDiffer<T> Instance = CustomDiffer.GetDiffer<T>();
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}
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private static readonly ICustomDiffer CustomDiffer =
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CustomDiffer<CustomDiffable>.Map(x => new { v = x.X });
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}
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}
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}

‎tests/Diffract.Tests/Tests.fs

Lines changed: 35 additions & 26 deletions
Original file line numberDiff line numberDiff line change
@@ -88,6 +88,14 @@ module MyDiffModule =
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let differ<'T> = CustomDiffer().GetDiffer<'T>()
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module MyDiffWithCombinators =
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let customDiffer = CustomDiffer<CustomDiffable>.Build(fun factory ->
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let stringDiffer = factory.GetDiffer<string>()
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fun x1 x2 -> stringDiffer.Diff(x1.x, x2.x))
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let differ<'T> = customDiffer.GetDiffer<'T>()
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type MyDiffer(differFactory: IDifferFactory) =
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let stringDiffer = differFactory.GetDiffer<string>()
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@@ -105,61 +113,62 @@ type MyCustomDiffer() =
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type MyDiffType<'T>() =
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static member val Differ = MyCustomDiffer().GetDiffer<'T>()
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type MyDiffTypeWithCombinators<'T>() =
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static let customDiffer = CustomDiffer<CustomDiffable>.Build(fun factory ->
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let stringDiffer = factory.GetDiffer<string>()
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fun x1 x2 -> stringDiffer.Diff(x1.x, x2.x))
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static member val Differ = customDiffer.GetDiffer<'T>()
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[<Fact>]
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let ``Custom differ`` () =
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Assert.Equal("x Expect = \"a\"\n Actual = \"b\"\n",
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Differ.ToString({ x = "a" }, { x = "b" }))
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Assert.Equal("Expect = \"a\"\nActual = \"b\"\n",
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Differ.ToString({ x = "a" }, { x = "b" }, MyDiffModule.differ))
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Assert.Equal("Expect = \"a\"\nActual = \"b\"\n",
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Differ.ToString({ x = "a" }, { x = "b" }, MyDiffWithCombinators.differ))
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Assert.Equal("Expect = \"a\"\nActual = \"b\"\n",
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Differ.ToString({ x = "a" }, { x = "b" }, MyDiffType.Differ))
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Assert.Equal("Expect = \"a\"\nActual = \"b\"\n",
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Differ.ToString({ x = "a" }, { x = "b" }, MyDiffTypeWithCombinators.Differ))
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module ``Custom differ with custom diff output`` =
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type MyCustomDiffer() =
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interface ICustomDiffer with
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member this.GetCustomDiffer<'T>(_, shape) =
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if shape.Type = typeof<CustomDiffable> then
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{ new IDiffer<CustomDiffable> with
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member _.Diff(x1, x2) =
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if x1.x = x2.x then
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None
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else
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Diff.MakeCustom(fun writer param indent path recur ->
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if param.ensureFirstLineIsAligned then writer.WriteLine()
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let indentLike str = String.replicate (String.length str) " "
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let dpath = if path = "" then "" else path + " "
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writer.WriteLine($"{indent}{dpath}{param.x1Name} __is__ {x1.x}")
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writer.WriteLine($"{indent}{indentLike dpath}{param.x2Name} __is__ {x2.x}"))
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|> Some }
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|> unbox<IDiffer<'T>>
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|> Some
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else
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None
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let myCustomDiffer = CustomDiffer<CustomDiffable>.Build(fun x1 x2 ->
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if x1.x = x2.x then
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None
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else
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Diff.MakeCustom(fun writer param indent path recur ->
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if param.ensureFirstLineIsAligned then writer.WriteLine()
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let indentLike str = String.replicate (String.length str) " "
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let dpath = if path = "" then "" else path + " "
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writer.WriteLine($"{indent}{dpath}{param.x1Name} __is__ {x1.x}")
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writer.WriteLine($"{indent}{indentLike dpath}{param.x2Name} __is__ {x2.x}"))
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|> Some)
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140-
type MyDiffType<'T>() =
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static member val Differ = MyCustomDiffer().GetDiffer<'T>()
150+
let differ<'T> = myCustomDiffer.GetDiffer<'T>()
142151

143152
[<Fact>]
144153
let ``Assert with immediate value adds newline`` () =
145154
let ex = Assert.Throws<AssertionFailedException>(fun () ->
146-
Differ.Assert({ x = "a" }, { x = "b" }, MyDiffType.Differ))
155+
Differ.Assert({ x = "a" }, { x = "b" }, differ))
147156
Assert.Equal("\nExpect __is__ a\nActual __is__ b\n", ex.Message)
148157

149158
[<Fact>]
150159
let ``Assert with nested value doesn't add newline`` () =
151160
let ex = Assert.Throws<AssertionFailedException>(fun () ->
152-
Differ.Assert({| i = { x = "a" } |}, {| i = { x = "b" } |}, MyDiffType.Differ))
161+
Differ.Assert({| i = { x = "a" } |}, {| i = { x = "b" } |}, differ))
153162
Assert.Equal("i Expect __is__ a\n Actual __is__ b\n", ex.Message)
154163

155164
[<Fact>]
156165
let ``ToString with immediate value doesn't add newline`` () =
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let diff = Differ.ToString({ x = "a" }, { x = "b" }, MyDiffType.Differ)
166+
let diff = Differ.ToString({ x = "a" }, { x = "b" }, differ)
158167
Assert.Equal("Expect __is__ a\nActual __is__ b\n", diff)
159168

160169
[<Fact>]
161170
let ``ToString with nested value doesn't add newline`` () =
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let diff = Differ.ToString({| i = { x = "a" } |}, {| i = { x = "b" } |}, MyDiffType.Differ)
171+
let diff = Differ.ToString({| i = { x = "a" } |}, {| i = { x = "b" } |}, differ)
163172
Assert.Equal("i Expect __is__ a\n Actual __is__ b\n", diff)
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165174
type Rec = { xRec: Rec option }

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