Question

The following code triggers a formatting warning on each let (“possible incorrect indentation”):

module UtilTests =
    [<Test>] let simpleWithNth ()= true |> should be True
    [<Test>] let negIndex () = true |> should be True
    [<Test>] let tooBigIndex () = true |> should be True
    [<Test>] let lastIndex () = true |> should be True

The following does not:

module UtilTests =
    [<Test>] let simpleWithNth ()= true |> should be True
     [<Test>] let negIndex () = true |> should be True
      [<Test>] let tooBigIndex () = true |> should be True
       [<Test>] let lastIndex () = true |> should be True

Why does it want each let to be more indented than the one above it? (Is there some way to have Visual Studio 2012 auto-format?)

Answer 1

As Brian said in the comment, the usual way of applying attributes to a let function is to write the attribute on the line before the let binding. I would also expect the code you wrote to work, because the body of the function is on the same line, but apparently, the compiler does not think so….

However, there is another way to apply attributes to let functions that works well in your example:

module UtilTests = 
  let [<Test>] simpleWithNth ()= true |> should be True 
  let [<Test>] negIndex () = true |> should be True 
  let [<Test>] tooBigIndex () = true |> should be True 
  let [<Test>] lastIndex () = true |> should be True 

This style is needed if you’re writing recursive functions – then attributes on previous lines do not work and you need to write let rec [<Foo>] foo () = ... and [<Bar>] bar () = ....