Merge pull request #3606 from fable-compiler/fix/record_equality

src/Fable.Cli/CHANGELOG.md

@@ -33,6 +33,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Fixed char to string type regression with binary operator (by @dbrattli)
 * Fix `DateTime(..., DateTimeKind.Local).ToString("O")` (by @MangelMaxime)
 * Fix calling `value.ToString(CultureInfo.InvariantCulture)` (by @MangelMaxime)
+* Fix #3605: Fix record equality comparison to works with optional fields (by @MangelMaxime & @dbrattli)
 
 ## 4.5.0 - 2023-11-07
 

src/fable-library-py/fable_library/types.py

@@ -118,19 +118,32 @@ def record_compare_to(self: Record, other: Record) -> int:
     if self is other:
         return 0
 
-    elif hasattr(self, "__dict__") and self.__dict__:
-        for name in self.__dict__.keys():
-            if self.__dict__[name] < other.__dict__.get(name):
+    def compare_values(self_value: Any, other_value: Any) -> int:
+        match (self_value, other_value):
+            case (None, None):
+                return 0
+            case (None, _):
+                return -1
+            case (_, None):
+                return 1
+            case (self_value, other_value) if self_value < other_value:
                 return -1
-            elif self.__dict__[name] > other.__dict__.get(name):
+            case (self_value, other_value) if self_value > other_value:
                 return 1
+            case _:
+                return 0
+
+    if hasattr(self, "__dict__") and self.__dict__:
+        for name in self.__dict__.keys():
+            result = compare_values(self.__dict__[name], other.__dict__[name])
+            if result != 0:
+                return result
 
     elif hasattr(self, "__slots__") and self.__slots__:
         for name in self.__slots__:
-            if getattr(self, name) < getattr(other, name):
-                return -1
-            elif getattr(self, name) > getattr(other, name):
-                return 1
+            result = compare_values(getattr(self, name), getattr(other, name))
+            if result != 0:
+                return result
 
     return 0
 

tests/Python/TestRecordType.fs

@@ -42,6 +42,9 @@ type Time =
 type CarInterior = { Seats: int }
 type Car = { Interior: CarInterior }
 
+type RecordA =
+    { OptionalField : string option }
+
 [<Fact>]
 let ``test Anonymous records work`` () =
     let r = makeAnonRec()
@@ -144,3 +147,14 @@ let ``test Nested record field copy and update works for anonymous records`` =
     let car2 =
         {| car with Interior.Seats = 5 |}
     equal 5 car2.Interior.Seats
+
+[<Fact>]
+let ``test Record equality when it has optional field`` =
+    let a = { OptionalField = None }
+    let b = { OptionalField = None }
+    let c = { OptionalField = Some "test" }
+
+    equal a b
+    equal true (a = b)
+    equal false (a = c)
+    equal false (c = b)