DeepHash

src/DynamicObj/DynamicObj.fs

@@ -75,7 +75,7 @@
         | Some pi -> Some pi
         | None -> this.TryGetDynamicPropertyHelper propertyName
 
     /// <summary>
     /// Returns Some(boxed property value) if a dynamic (or static) property with the given name exists, otherwise None.
     /// </summary>
     /// <param name="name">the name of the property to get</param>
@@ -388,18 +388,49 @@
     static member (?<-) (lookup:#DynamicObj,name:string,value:'v) =
         lookup.SetProperty (name,value)
 
+    member this.ReferenceEquals (other: DynamicObj) = System.Object.ReferenceEquals(this,other)
+
+    member this.StructurallyEquals (other: DynamicObj) =
+        this.GetHashCode() = other.GetHashCode()
+
     override this.GetHashCode () =
-        this.GetProperties(true)
-        |> Seq.sortBy (fun pair -> pair.Key)
-        |> HashCodes.boxHashKeyValSeq
-        |> fun x -> x :?> int
+        HashUtils.deepHash this
 
     override this.Equals o =
         match o with
         | :? DynamicObj as other ->
-            this.GetHashCode() = other.GetHashCode()
+            this.StructurallyEquals(other)
         | _ -> false
 
+and HashUtils = 
+
+    static member deepHash (o:obj) =
+        match o with
+        | :? DynamicObj as o ->
+            o.GetProperties(true)
+            |> Seq.sortBy (fun pair -> pair.Key)
+            |> HashCodes.boxHashKeyValSeqBy HashUtils.deepHash
+            |> fun x -> x :?> int
+        | :? string as s -> DynamicObj.HashCodes.hash s
+        #if !FABLE_COMPILER
+        | :? System.Collections.IDictionary as d -> 
+            let mutable en = d.GetEnumerator()
+            [
+                while en.MoveNext() do 
+                    let c = en.Current :?> System.Collections.DictionaryEntry
+                    HashCodes.mergeHashes (hash c.Key) (HashUtils.deepHash c.Value)
+            ]
+            |> List.reduce HashCodes.mergeHashes
+        #endif
+        | :? System.Collections.IEnumerable as e ->
+            let en = e.GetEnumerator()
+            [
+                while en.MoveNext() do 
+                    HashUtils.deepHash en.Current
+            ]
+            |> List.reduce HashCodes.mergeHashes
+        | _ -> DynamicObj.HashCodes.hash o
+
 and CopyUtils =
 
     /// <summary>

src/DynamicObj/HashCodes.fs

@@ -1,5 +1,12 @@
 module DynamicObj.HashCodes
 
+// Taken from
+//https://softwareengineering.stackexchange.com/a/402543
+// Which points to a no-longer existing source in FSharp Core Compiler
+// But can be found in 
+// https://github.com/dotnet/fsharp/blob/2edab1216843f20a00a7d8f171aca52cbc35d7fd/src/Compiler/Checking/AugmentWithHashCompare.fs#L171
+// Or Fables mirror
+// https://github.com/fable-compiler/Fable/blob/b0e640763fd90bd084f72531cb119d49a91ec077/src/fcs-fable/src/Compiler/Checking/AugmentWithHashCompare.fs#L171
 let mergeHashes (hash1 : int) (hash2 : int) : int =
     0x9e3779b9 + hash2 + (hash1 <<< 6) + (hash1 >>> 2)
 
@@ -46,4 +53,12 @@ let boxHashKeyValSeq (a: seq<System.Collections.Generic.KeyValuePair<'a,'b>>) :
     |> Seq.fold (fun acc o -> 
         mergeHashes (hash o.Key) (hash o.Value)
         |> mergeHashes acc) 0
+    |> box
+
+let boxHashKeyValSeqBy (f : 'b -> int) (a: seq<System.Collections.Generic.KeyValuePair<'a,'b>>) : obj =
+    a 
+    // from https://stackoverflow.com/a/53507559
+    |> Seq.fold (fun acc o -> 
+        mergeHashes (hash o.Key) (f o.Value)
+        |> mergeHashes acc) 0
     |> box

tests/DynamicObject.Tests/DynamicObject.Tests.fsproj

@@ -33,6 +33,7 @@
     <Compile Include="DynamicObj\DeepCopyProperties.fs" />
     <Compile Include="DynamicObj\Main.fs" />
     <Compile Include="ReflectionUtils.fs" />
+    <Compile Include="HashUtils.fs" />
     <Compile Include="Inheritance.fs" />
     <Compile Include="Interface.fs" />
     <Compile Include="DynObj.fs" />

tests/DynamicObject.Tests/HashUtils.fs

@@ -0,0 +1,275 @@
+module HashUtils.Tests
+
+open System
+open Fable.Pyxpecto
+open DynamicObj
+open Fable.Core
+
+let int1 = box 1
+let int2 = box 2
+let int3 = box 3
+let int4 = box 4
+
+let intDict1 = 
+    let d = System.Collections.Generic.Dictionary<obj, obj>()
+    d.Add(int1, int2)
+    d.Add(int3, int4)
+    d
+
+let intDict1' = 
+    let d = System.Collections.Generic.Dictionary<obj, obj>()
+    d.Add(int1, int2)
+    d.Add(int3, int4)
+    d
+
+let intDict2 =
+    let d = System.Collections.Generic.Dictionary<obj, obj>()
+    d.Add(int1, int4)
+    d.Add(int3, int2)
+    d
+
+let intDict3 =
+    let d = System.Collections.Generic.Dictionary<obj, obj>()
+    d.Add(int2, int1)
+    d.Add(int4, int3)
+    d
+
+let intDict4 =
+    let d = System.Collections.Generic.Dictionary<obj, obj>()
+    d.Add(int1, int3)
+    d.Add(int2, int4)
+    d
+
+let intList1 = [int1;int2;int3;int4]
+let intList1' = [int1;int2;int3;int4]
+let intList2 = [int1;int4;int3;int2]
+
+let nestedList1 = [intList1;intList2]
+let nestedList1' = [intList1';intList2]
+let nestedList2 = [intList2;intList1]
+
+let intArray1 = [|int1;int2;int3;int4|]
+let intArray1' = [|int1;int2;int3;int4|]
+let intArray2 = [|int1;int4;int3;int2|]
+
+let intSeq1 = seq { yield int1; yield int2; yield int3; yield int4 }
+let intSeq1' = seq { yield int1; yield int2; yield int3; yield int4 }
+let intSeq2 = seq { yield int1; yield int4; yield int3; yield int2 }
+
+let resizeArray1 = ResizeArray [int1;int2;int3;int4]
+let resizeArray1' = ResizeArray [int1;int2;int3;int4]
+let resizeArray2 = ResizeArray [int1;int4;int3;int2]
+
+
+let dynamicObjectWithInt1 =
+
+    let d = DynamicObj()
+    d.SetProperty("a", int1)
+    d.SetProperty("b", int2)
+    d
+
+let dynamicObjectWithInt1DiffKey =
+    let d = DynamicObj()
+    d.SetProperty("a", int1)
+    d.SetProperty("c", int2)
+    d
+
+let dynamicObjectWithInt1' =  
+    let d = DynamicObj()
+    d.SetProperty("a", int1)
+    d.SetProperty("b", int2)
+    d
+
+let dynamicObjectWithInt2 =
+    let d = DynamicObj()
+    d.SetProperty("a", int2)
+    d.SetProperty("b", int1)
+    d
+
+let dynamicObjectWithDict1 =
+    let d = DynamicObj()
+    d.SetProperty("a", intDict1)
+    d.SetProperty("b", intDict2)
+    d
+
+let dynamicObjectWithDict1' =
+    let d = DynamicObj()
+    d.SetProperty("a", intDict1)
+    d.SetProperty("b", intDict2)
+    d
+
+let dynamicObjectWithDict2 =
+    let d = DynamicObj()
+    d.SetProperty("a", intDict2)
+    d.SetProperty("b", intDict1)
+    d
+
+let dynamicObjectWithDynamicObject1 =
+    let d = DynamicObj()
+    d.SetProperty("a", dynamicObjectWithInt1)
+    d.SetProperty("b", dynamicObjectWithInt2)
+    d
+
+let dynamicObjectWithDynamicObject1' =
+    let d = DynamicObj()
+    d.SetProperty("a", dynamicObjectWithInt1)
+    d.SetProperty("b", dynamicObjectWithInt2)
+    d
+
+let dynamicObjectWithDynamicObject2 =
+    let d = DynamicObj()
+    d.SetProperty("a", dynamicObjectWithInt2)
+    d.SetProperty("b", dynamicObjectWithDict1)
+    d
+
+
+let tests_Dictionary =
+    testList "Dictionary" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->               
+                Expect.equal (HashUtils.deepHash intDict1) (HashUtils.deepHash intDict1) "Same Dictionary should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash intDict1) (HashUtils.deepHash intDict1') "Structurally equal Dictionary should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intDict1) (HashUtils.deepHash intDict2) "Different Dictionary should return different Hash (1vs2)"
+            testCase "1v3" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intDict1) (HashUtils.deepHash intDict3) "Different Dictionary should return different Hash (1vs3)"
+            testCase "1v4" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intDict1) (HashUtils.deepHash intDict4) "Different Dictionary should return different Hash (1vs4)"
+            testCase "2v3" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intDict2) (HashUtils.deepHash intDict3) "Different Dictionary should return different Hash (2vs3)"
+            testCase "2v4" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intDict2) (HashUtils.deepHash intDict4) "Different Dictionary should return different Hash (2vs4)"
+
+        ]
+    ]
+
+let tests_Lists = 
+    testList "Lists" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->               
+                Expect.equal (HashUtils.deepHash intList1) (HashUtils.deepHash intList1) "Same List should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash intList1) (HashUtils.deepHash intList1') "Structurally equal List should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intList1) (HashUtils.deepHash intList2) "Different List should return different Hash"
+        ]
+        testList "Shuffled Nested" [
+            testCase "1v1" <| fun _ ->               
+                Expect.equal (HashUtils.deepHash nestedList1) (HashUtils.deepHash nestedList1) "Same Nested List should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash nestedList1) (HashUtils.deepHash nestedList1') "Structurally equal Nested List should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash nestedList1) (HashUtils.deepHash nestedList2) "Different Nested List should return different Hash"
+
+        ]
+    ]
+
+let tests_Array = 
+    testList "Array" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->               
+                Expect.equal (HashUtils.deepHash intArray1) (HashUtils.deepHash intArray1) "Same Array should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash intArray1) (HashUtils.deepHash intArray1') "Structurally equal Array should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intArray1) (HashUtils.deepHash intArray2) "Different Array should return different Hash"
+        ]
+    ]
+
+let tests_Seq = 
+    testList "Seq" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->               
+                Expect.equal (HashUtils.deepHash intSeq1) (HashUtils.deepHash intSeq1) "Same Seq should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash intSeq1) (HashUtils.deepHash intSeq1') "Structurally equal Seq should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash intSeq1) (HashUtils.deepHash intSeq2) "Different Seq should return different Hash"
+        ]
+    ]
+
+let tests_ResizeArray = 
+    testList "ResizeArray" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->
+
+                Expect.equal (HashUtils.deepHash resizeArray1) (HashUtils.deepHash resizeArray1) "Same ResizeArray should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash resizeArray1) (HashUtils.deepHash resizeArray1') "Structurally equal ResizeArray should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash resizeArray1) (HashUtils.deepHash resizeArray2) "Different ResizeArray should return different Hash"
+        ]
+    ]
+
+
+let tests_DynamicObject = 
+    testList "DynamicObj" [
+        testList "Shuffled Int" [
+            testCase "1v1" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithInt1) (HashUtils.deepHash dynamicObjectWithInt1) "Same DynamicObject should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithInt1) (HashUtils.deepHash dynamicObjectWithInt1') "Structurally equal DynamicObject should return consistent Hash"
+            testCase "1v1DiffKey" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithInt1) (HashUtils.deepHash dynamicObjectWithInt1DiffKey) "Different DynamicObject should return different Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithInt1) (HashUtils.deepHash dynamicObjectWithInt2) "Different DynamicObject should return different Hash"
+        ]
+        testList "Shuffled Dict" [
+            testCase "1v1" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithDict1) (HashUtils.deepHash dynamicObjectWithDict1) "Same DynamicObject should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithDict1) (HashUtils.deepHash dynamicObjectWithDict1') "Structurally equal DynamicObject should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithDict1) (HashUtils.deepHash dynamicObjectWithDict2) "Different DynamicObject should return different Hash"
+        ]
+        testList "Shuffled DynamicObject" [
+            testCase "1v1" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithDynamicObject1) (HashUtils.deepHash dynamicObjectWithDynamicObject1) "Same DynamicObject should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash dynamicObjectWithDynamicObject1) (HashUtils.deepHash dynamicObjectWithDynamicObject1') "Structurally equal DynamicObject should return consistent Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithDynamicObject1) (HashUtils.deepHash dynamicObjectWithDynamicObject2) "Different DynamicObject should return different Hash"
+        ]
+        testList "Shuffled Int AsOption" [
+            testCase "1v1" <| fun _ ->
+                Expect.equal (HashUtils.deepHash (Some dynamicObjectWithInt1)) (HashUtils.deepHash (Some dynamicObjectWithInt1)) "Same DynamicObject should return consistent Hash"
+            testCase "1v1'" <| fun _ ->
+                Expect.equal (HashUtils.deepHash (Some dynamicObjectWithInt1)) (HashUtils.deepHash (Some dynamicObjectWithInt1')) "Structurally equal DynamicObject should return consistent Hash"
+            testCase "1v1DiffKey" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash (Some dynamicObjectWithInt1)) (HashUtils.deepHash (Some dynamicObjectWithInt1DiffKey)) "Different DynamicObject should return different Hash"
+            testCase "1v2" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash (Some dynamicObjectWithInt1)) (HashUtils.deepHash (Some dynamicObjectWithInt2)) "Different DynamicObject should return different Hash"
+            testCase "1 v None" <| fun _ ->
+                Expect.notEqual (HashUtils.deepHash (Some dynamicObjectWithInt1)) (HashUtils.deepHash None) "Different DynamicObject should return different Hash"
+
+        ]
+        testList "Mixed" [
+            testCase "Int vs Dict" <| fun _ ->               
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithInt1) (HashUtils.deepHash dynamicObjectWithDict1) "Int vs Dict with same values should return different Hash"
+            testCase "Dict vs DynObj" <| fun _ ->               
+                Expect.notEqual (HashUtils.deepHash dynamicObjectWithDict1) (HashUtils.deepHash dynamicObjectWithDynamicObject1) "Dict vs DynObj with same values should return different Hash"           
+        ]
+    ]
+
+
+let tests_Mixed = 
+    testList "Mixed" [
+        testCase "Int vs Dict" <| fun _ ->               
+            Expect.notEqual (HashUtils.deepHash int1) (HashUtils.deepHash intDict1) "Int vs Dict with same values should return different Hash"
+        testCase "List vs Dict" <| fun _ ->               
+            Expect.notEqual (HashUtils.deepHash intList1) (HashUtils.deepHash intDict1) "List vs Dict with same values should return different Hash"
+    ]
+
+
+
+
+let main = testList "DeepHash" [
+    tests_Dictionary
+    tests_Lists
+    tests_Array
+    tests_Seq
+    tests_ResizeArray
+    tests_DynamicObject
+    tests_Mixed
+]

tests/DynamicObject.Tests/Main.fs

@@ -4,6 +4,7 @@ open Fable.Pyxpecto
 
 let all = testSequenced <| testList "DynamicObj" [
     ReflectionUtils.Tests.main
+    HashUtils.Tests.main
     CopyUtils.Tests.main
     DynamicObj.Tests.main
     DynObj.Tests.main