IEnumerable iteration

tests/FSharp.Compiler.ComponentTests/Conformance/Expressions/ControlFlowExpressions/SequenceIteration/IEnumerableIterationGenericDisposal01.fs

@@ -0,0 +1,70 @@
+// #Conformance #ControlFlow #Sequences #Regression #InterfacesAndImplementations
+// Ensure generic IEnumerable iteration calls GetEnumerator and disposes enumerators via try/finally.
+
+open System
+open System.Collections
+open System.Collections.Generic
+
+type CountingEnumerable(values: int[]) =
+    static let mutable getEnumeratorCalls = 0
+    static let mutable disposeCalls = 0
+
+    static member Reset() =
+        getEnumeratorCalls <- 0
+        disposeCalls <- 0
+
+    static member GetEnumeratorCalls = getEnumeratorCalls
+    static member DisposeCalls = disposeCalls
+
+    interface IEnumerable<int> with
+        member _.GetEnumerator() =
+            getEnumeratorCalls <- getEnumeratorCalls + 1
+            let mutable i = -1
+
+            { new IEnumerator<int> with
+                member _.Current = values[i]
+
+              interface IEnumerator with
+                  member _.Current = box values[i]
+                  member _.MoveNext() =
+                      i <- i + 1
+                      i < values.Length
+                  member _.Reset() = i <- -1
+
+              interface IDisposable with
+                  member _.Dispose() = disposeCalls <- disposeCalls + 1 }
+
+    interface IEnumerable with
+        member this.GetEnumerator() =
+            (this :> IEnumerable<int>).GetEnumerator() :> IEnumerator
+
+let runSuccessfulIteration () =
+    CountingEnumerable.Reset()
+
+    let enumerable = CountingEnumerable([| 1; 2; 3 |]) :> IEnumerable<int>
+    let mutable sum = 0
+
+    for x in enumerable do
+        sum <- sum + x
+
+    sum = 6
+    && CountingEnumerable.GetEnumeratorCalls = 1
+    && CountingEnumerable.DisposeCalls = 1
+
+let runExceptionalIteration () =
+    CountingEnumerable.Reset()
+
+    let enumerable = CountingEnumerable([| 1; 2; 3 |]) :> IEnumerable<int>
+
+    try
+        for x in enumerable do
+            if x = 2 then
+                failwith "boom"
+    with _ ->
+        ()
+
+    CountingEnumerable.GetEnumeratorCalls = 1
+    && CountingEnumerable.DisposeCalls = 1
+
+let ok = runSuccessfulIteration () && runExceptionalIteration ()
+exit (if ok then 0 else 1)

tests/FSharp.Compiler.ComponentTests/Conformance/Expressions/ControlFlowExpressions/SequenceIteration/SequenceIteration.fs

@@ -9,7 +9,37 @@ open FSharp.Test.Compiler
 module SequenceIteration =
 
     // This test was automatically generated (moved from FSharpQA suite - Conformance/Expressions/ControlFlowExpressions/SequenceIteration)
-
+
+    let verifyCompileAndRun compilation =
+        compilation
+        |> asExe
+        |> withOptions ["--nowarn:3370"]
+        |> compileExeAndRun
+
+    [<Theory; FileInlineData("IEnumerableIteration01.fs")>]
+    let ``IEnumerableIteration01_fs`` compilation =
+        compilation
+        |> getCompilation
+        |> asFsx
+        |> verifyCompileAndRun
+        |> shouldSucceed
+
+    [<Theory; FileInlineData("IEnumerableIterationGenericDisposal01.fs")>]
+    let ``IEnumerableIterationGenericDisposal01_fs`` compilation =
+        compilation
+        |> getCompilation
+        |> asFsx
+        |> verifyCompileAndRun
+        |> shouldSucceed
+
+    [<Theory; FileInlineData("E_BadIEnumerable01.fs")>]
+    let ``E_BadIEnumerable01_fs`` compilation =
+        compilation
+        |> getCompilation
+        |> asFsx
+        |> typecheck
+        |> shouldFail
+
     [<Theory; FileInlineData("W_IncompleteMatchFor01.fs")>]
     let ``W_IncompleteMatchFor01_fs`` compilation =
         compilation
@@ -26,4 +56,3 @@ module SequenceIteration =
             (Warning 25, Line 22, Col 9, Line 22, Col 17, "Incomplete pattern matches on this expression. For example, the value 'None' may indicate a case not covered by the pattern(s).")
             (Warning 25, Line 27, Col 20, Line 27, Col 28, "Incomplete pattern matches on this expression. For example, the value 'None' may indicate a case not covered by the pattern(s).")
         ]
-