Remove a superfuous unindent for match lambda in AppWithLambda, fixes…

… 2214 (fsprojects#2215)

CHANGELOG.md

@@ -5,6 +5,9 @@
 ### Changed
 * Add `fable_modules` to the directories which are always excluded. [Fable 3.4](https://github.com/fable-compiler/Fable/releases/tag/3.4.0)
 
+### Fixed
+* Let binding after match lambda is moved outside of nested module. [#2214](https://github.com/fsprojects/fantomas/issues/2214)
+
 ## [4.7.8] - 2022-04-25
 
 ### Fixed

src/Fantomas.Tests/ModuleTests.fs

@@ -703,6 +703,45 @@ module App =
     val a: string
 """
 
+[<Test>]
+let ``keep correct indentation for let binding after match lambda inside nested module, 2214`` () =
+    formatSourceString
+        false
+        """
+module Outer
+
+let sort fallback (f: int -> string list) = ()
+
+module Inner =
+
+    let f =
+        sort
+            "Name"
+            (function
+             | 1 -> ["One"]
+             | _ -> ["Not One"])
+
+    let g () = 23
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+module Outer
+
+let sort fallback (f: int -> string list) = ()
+
+module Inner =
+
+    let f =
+        sort "Name" (function
+            | 1 -> [ "One" ]
+            | _ -> [ "Not One" ])
+
+    let g () = 23
+"""
+
 [<Test>]
 let ``nested nested module with single union DU, 1123`` () =
     formatSourceString

src/Fantomas/CodePrinter.fs

@@ -2200,7 +2200,6 @@ and genExpr astContext synExpr ctx =
                                     +> unindent
                                     |> genTriviaFor SynExpr_MatchLambda matchLambdaRange)
                                 +> sepNlnWhenWriteBeforeNewlineNotEmpty id
-                                +> unindent
                                 +> sepCloseTFor rpr)
                             |> genTriviaFor SynExpr_Paren pr