Consider all function applications as short branch.

src/Fantomas.Tests/KeepIndentInBranchTests.fs

@@ -1770,3 +1770,63 @@ let updateModuleInImpl (ast: ParsedInput) (mdl: SynModuleOrNamespace) : ParsedIn
     )
     |> ParsedInput.ImplFile
 """
+
+[<Test>]
+let ``short function application in if branch`` () =
+    formatSourceString
+        false
+        """
+let private parseModel (modelSrc: string) : Result<MyReturnType, string list> =
+  if not (File.Exists(modelSrc)) then
+    Error [ sprintf "Provided modelSrc \"%s\" does not exist" modelSrc ]
+  else
+    let graph = new QueryableGraph()
+    graph.LoadFromFile(modelSrc, TurtleParser())
+
+    let xsdPath =
+      Path.Combine(Directory.GetCurrentDirectory(), "Some.xsd")
+
+    let ontologyPath =
+      Path.Combine(Directory.GetCurrentDirectory(), "Some.ttl")
+
+    let ontoGraph = new OntologyGraph()
+    FileLoader.Load(ontoGraph, ontologyPath)
+
+    let validationErrors =
+      GraphValidation.validate xsdPath ontoGraph "http://company.com/meh" graph
+
+    if List.isEmpty validationErrors then
+      Ok graph
+    else
+      Error validationErrors
+"""
+        config
+    |> prepend newline
+    |> should
+        equal
+        """
+let private parseModel (modelSrc: string) : Result<MyReturnType, string list> =
+    if not (File.Exists(modelSrc)) then
+        Error [ sprintf "Provided modelSrc \"%s\" does not exist" modelSrc ]
+    else
+
+    let graph = new QueryableGraph()
+    graph.LoadFromFile(modelSrc, TurtleParser())
+
+    let xsdPath =
+        Path.Combine(Directory.GetCurrentDirectory(), "Some.xsd")
+
+    let ontologyPath =
+        Path.Combine(Directory.GetCurrentDirectory(), "Some.ttl")
+
+    let ontoGraph = new OntologyGraph()
+    FileLoader.Load(ontoGraph, ontologyPath)
+
+    let validationErrors =
+        GraphValidation.validate xsdPath ontoGraph "http://company.com/meh" graph
+
+    if List.isEmpty validationErrors then
+        Ok graph
+    else
+        Error validationErrors
+"""

src/Fantomas/SourceParser.fs

@@ -1721,7 +1721,7 @@ let private shouldNotIndentBranch e es =
         match e with
         | SimpleExpr _
         | Sequential (_, _, true)
-        | App (SimpleExpr _, [ SimpleExpr _ ]) -> true
+        | App _ -> true
         | _ -> false
 
     let isLongElseBranch e =