[Repo Assist] Add regression test for index-without-dot with variable key and unit arguments, 2519

CHANGELOG.md

@@ -13,6 +13,7 @@
 - NamedIndexedPropertySet with two SynLongIdent removed space. [#3273](https://github.com/fsprojects/fantomas/issues/3273)
 - `%%` (double-percent) infix operator moved to new line, producing invalid F#. [#2107](https://github.com/fsprojects/fantomas/issues/2107)
 - Indentation warning when formatting `match` with long anonymous record discriminant. [#1903](https://github.com/fsprojects/fantomas/issues/1903)
+- Index-without-dot with variable key followed by unit arguments added spurious spaces, e.g. `dict[key] () ()` became `dict [ key ] () ()`. [#2519](https://github.com/fsprojects/fantomas/issues/2519)
 
 ## [8.0.0-alpha-007] - 2026-03-10
 

src/Fantomas.Core.Tests/IndexSyntaxTests.fs

@@ -315,3 +315,22 @@ prepConfigs[ 1 ] host days
         """
 prepConfigs[1] host days
 """
+
+[<Test>]
+let ``index without dot with variable key followed by two unit arguments, 2519`` () =
+    formatSourceString
+        """
+let test (dict: System.Collections.Generic.IDictionary<string, unit -> unit -> unit>) =
+    let key = "foo"
+    dict[key] () ()
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let test (dict: System.Collections.Generic.IDictionary<string, unit -> unit -> unit>) =
+    let key = "foo"
+    dict[key] () ()
+"""
+