From 87747b1d62daa3ed3b26b39b20465b94b1c5d95b Mon Sep 17 00:00:00 2001
From: Brian Rourke Boll <brianrourkeboll@gmail.com>
Date: Thu, 25 Jul 2024 11:25:28 -0400
Subject: [PATCH 1/3] Don't throw if error range extends to EOF

---
 .../ChangePrefixNegationToInfixSubtraction.fs | 32 ++++++++++---------
 ...gePrefixNegationToInfixSubtractionTests.fs | 20 ++++++++++++
 2 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/vsintegration/src/FSharp.Editor/CodeFixes/ChangePrefixNegationToInfixSubtraction.fs b/vsintegration/src/FSharp.Editor/CodeFixes/ChangePrefixNegationToInfixSubtraction.fs
index 87841d5d57b..ee8b8870538 100644
--- a/vsintegration/src/FSharp.Editor/CodeFixes/ChangePrefixNegationToInfixSubtraction.fs
+++ b/vsintegration/src/FSharp.Editor/CodeFixes/ChangePrefixNegationToInfixSubtraction.fs
@@ -18,10 +18,13 @@ type internal ChangePrefixNegationToInfixSubtractionCodeFixProvider() =
     static let title = SR.ChangePrefixNegationToInfixSubtraction()
 
     static let rec findNextNonWhitespacePos (sourceText: SourceText) pos =
-        if pos < sourceText.Length && Char.IsWhiteSpace sourceText[pos] then
-            findNextNonWhitespacePos sourceText (pos + 1)
+        if pos < sourceText.Length - 1 then
+            if Char.IsWhiteSpace sourceText[pos] then
+                findNextNonWhitespacePos sourceText (pos + 1)
+            else
+                ValueSome pos
         else
-            pos
+            ValueNone
 
     override _.FixableDiagnosticIds = ImmutableArray.Create "FS0003"
 
@@ -34,16 +37,15 @@ type internal ChangePrefixNegationToInfixSubtractionCodeFixProvider() =
 
                 // in a line like "... x  -1 ...",
                 // squiggly goes for "x", not for "-", hence we search for "-"
-                let pos = findNextNonWhitespacePos sourceText (context.Span.End + 1)
-
-                if sourceText[pos] <> '-' then
-                    return ValueNone
-                else
-                    return
-                        ValueSome
-                            {
-                                Name = CodeFix.ChangePrefixNegationToInfixSubtraction
-                                Message = title
-                                Changes = [ TextChange(TextSpan(pos + 1, 0), " ") ]
-                            }
+                let fix =
+                    findNextNonWhitespacePos sourceText (context.Span.End + 1)
+                    |> ValueOption.filter (fun pos -> sourceText[pos] = '-')
+                    |> ValueOption.map (fun pos ->
+                        {
+                            Name = CodeFix.ChangePrefixNegationToInfixSubtraction
+                            Message = title
+                            Changes = [ TextChange(TextSpan(pos + 1, 0), " ") ]
+                        })
+
+                return fix
             }
diff --git a/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs b/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
index 5245d8a3ae0..156bdabbc30 100644
--- a/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
+++ b/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
@@ -48,3 +48,23 @@ let x = 1 (+) 2
     let actual = codeFix |> tryFix code Auto
 
     Assert.Equal(expected, actual)
+
+[<Fact>]
+let ``Doesn't throw when the error range extends to the end of the source text`` () =
+    let code =
+        """
+module Microsoft =
+module FSharp =
+    module Core =
+        module LanguagePrimitives =
+            module IntrinsicFunctions =
+                let GetArray2D _ _ = 99
+
+let a = Array2D.init 10 10 (+)
+a[5, 5]"""
+
+    let expected = None
+
+    let actual = codeFix |> tryFix code Auto
+
+    Assert.Equal(expected, actual)

From dcd7925438b1978c67cd5e7c1ff7a1cec702af80 Mon Sep 17 00:00:00 2001
From: Brian Rourke Boll <brianrourkeboll@gmail.com>
Date: Thu, 25 Jul 2024 11:32:04 -0400
Subject: [PATCH 2/3] Add release notes entry

---
 docs/release-notes/.VisualStudio/17.12.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 docs/release-notes/.VisualStudio/17.12.md

diff --git a/docs/release-notes/.VisualStudio/17.12.md b/docs/release-notes/.VisualStudio/17.12.md
new file mode 100644
index 00000000000..6df973cf607
--- /dev/null
+++ b/docs/release-notes/.VisualStudio/17.12.md
@@ -0,0 +1,9 @@
+### Fixed
+
+* In the prefix-to-infix code fix, don't throw an exception if the error range for FS0003 extends through the end of the source text. ([PR #17448](https://github.com/dotnet/fsharp/pull/17448))
+
+### Added
+
+### Changed
+
+### Breaking Changes

From 4e010cc764e3a718de016ec55949151a0341e71e Mon Sep 17 00:00:00 2001
From: Brian Rourke Boll <brianrourkeboll@gmail.com>
Date: Thu, 25 Jul 2024 11:41:18 -0400
Subject: [PATCH 3/3] Indent

---
 .../ChangePrefixNegationToInfixSubtractionTests.fs     | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs b/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
index 156bdabbc30..b93055a3a90 100644
--- a/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
+++ b/vsintegration/tests/FSharp.Editor.Tests/CodeFixes/ChangePrefixNegationToInfixSubtractionTests.fs
@@ -54,11 +54,11 @@ let ``Doesn't throw when the error range extends to the end of the source text``
     let code =
         """
 module Microsoft =
-module FSharp =
-    module Core =
-        module LanguagePrimitives =
-            module IntrinsicFunctions =
-                let GetArray2D _ _ = 99
+    module FSharp =
+        module Core =
+            module LanguagePrimitives =
+                module IntrinsicFunctions =
+                    let GetArray2D _ _ = 99
 
 let a = Array2D.init 10 10 (+)
 a[5, 5]"""