Merge branch 'main' into repo-assist/codescan-interpolated-strings-1128-1143-1517-1518-380ff3b7c73331e7

Author: MangelMaxime

src/Fable.Cli/CHANGELOG.md

@@ -9,8 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-* [Rust] Add type format specifiers to interpolated strings in Fable2Rust.fs (code scanning alerts #1128–#1143)
-* [All] Add type format specifiers to interpolated strings in Fable.Compiler/Util.fs (code scanning alerts #1517–#1518)
+* [All] Fix captured side-effect-free values (e.g. empty ResizeArray) being incorrectly inlined into object expression getters in release mode, causing a new instance to be created on each getter call (fixes #3779) (by @MangelMaxime)
 * [Python] Fix missing `await` on else branch of ternary expressions in async closures (by @dbrattli)
 * [Beam] Fix `|> ignore` on cross-module Emit calls generating variable bindings that shadow Emit case-clause variables (by @dbrattli)
 * [Beam] Fix `containsIdentRef` not checking `Call` ThisArg (by @dbrattli)

src/Fable.Compiler/CHANGELOG.md

@@ -9,8 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
-* [Rust] Add type format specifiers to interpolated strings in Fable2Rust.fs (code scanning alerts #1128–#1143)
-* [All] Add type format specifiers to interpolated strings in Fable.Compiler/Util.fs (code scanning alerts #1517–#1518)
+* [All] Fix captured side-effect-free values (e.g. empty ResizeArray) being incorrectly inlined into object expression getters in release mode, causing a new instance to be created on each getter call (fixes #3779) (by @MangelMaxime)
 * [Python] Fix missing `await` on else branch of ternary expressions in async closures (by @dbrattli)
 * [Beam] Fix `|> ignore` on cross-module Emit calls generating variable bindings that shadow Emit case-clause variables (by @dbrattli)
 * [Beam] Fix `containsIdentRef` not checking `Call` ThisArg (by @dbrattli)

src/Fable.Transforms/FableTransforms.fs

@@ -242,7 +242,22 @@ let canInlineArg (com: Compiler) identName value body =
     | _ ->
         let refCount = countReferencesUntil 2 identName body
 
-        (refCount <= 1 && not (canHaveSideEffects com value))
+        // Don't inline values that create new mutable state (e.g. ResizeArray(), mutable arrays)
+        // into closures: even though creation is side-effect-free, inlining into a closure
+        // called multiple times would create a new instance per call instead of sharing the
+        // single captured instance
+        let createsMutableState =
+            match value with
+            | Value(NewArray(_, _, kind), _) ->
+                match kind with
+                | MutableArray
+                | ResizeArray -> true
+                | ImmutableArray -> false
+            | _ -> false
+
+        (refCount <= 1
+         && not (canHaveSideEffects com value)
+         && not (createsMutableState && isIdentCaptured identName body))
         // If it can have side effects, make sure is at least referenced once so the expression is not erased
         || (refCount = 1
             && noSideEffectBeforeIdent identName body

tests/Js/Main/TypeTests.fs

@@ -657,6 +657,10 @@ type MangledAbstractClass5(v) =
     inherit MangledAbstractClass4(v + 5)
     override _.MyMethod(x: int) = base.MyMethod(x) + v + 7
 
+[<AbstractClass>]
+type AbstractClassWithResizeArrayProp() =
+    abstract Warnings: ResizeArray<string> with get
+
 type ConcreteClass1() =
     inherit MangledAbstractClass5(2)
 
@@ -1621,4 +1625,17 @@ let tests =
         top.A |> equal 0
         top.B.A |> equal 0
         top.B.B |> equal false
+
+    testCase "Abstract class property backed by captured variable in object expression works" <| fun () ->
+        let warnings = ResizeArray<string>()
+
+        let reader =
+            { new AbstractClassWithResizeArrayProp() with
+                member __.Warnings = warnings
+            }
+
+        reader.Warnings.Add("Warning 1")
+        reader.Warnings.Add("Warning 2")
+
+        reader.Warnings.Count |> equal 2
   ]

tests/Python/TestType.fs

@@ -577,6 +577,10 @@ type MangledAbstractClass5(v) =
     inherit MangledAbstractClass4(v + 5)
     override _.MyMethod(x: int) = base.MyMethod(x) + v + 7
 
+[<AbstractClass>]
+type AbstractClassWithResizeArrayProp() =
+    abstract Warnings: ResizeArray<string> with get
+
 type ConcreteClass1() =
     inherit MangledAbstractClass5(2)
 
@@ -1776,3 +1780,17 @@ let ``test Unchecked.defaultof works for fields on structs`` () =
     top.A |> equal 0
     top.B.A |> equal 0
     top.B.B |> equal false
+
+[<Fact>]
+let ``test Abstract class property backed by captured variable in object expression works`` () =
+    let warnings = ResizeArray<string>()
+
+    let reader =
+        { new AbstractClassWithResizeArrayProp() with
+            member __.Warnings = warnings
+        }
+
+    reader.Warnings.Add("Warning 1")
+    reader.Warnings.Add("Warning 2")
+
+    reader.Warnings.Count |> equal 2