[STYLE_bug] When styling does not find a box::use, all lines are converted into NA

[radbasa]

          @jakubnowicki Will need to go back to `box.linters::style_*`.

0.10.2 converts:

# View: Shiny modules and related code.
# https://go.appsilon.com/rhino-project-structure

to

NA
NA

Originally posted by @radbasa in Appsilon/rhino#607 (comment)

[radbasa]

We can do either of two things:

1. Implement and activate the exclude_files parameter of box.linters::style_box_use_dir()
2. Fix the bug converting the comment-only file to NA.

[jakubnowicki]

Recently this also happened when there was no empty line between box::use() and the rest of the code:

box::use(
  app/main,
)
context("Test main$format_duration()")
test_that("format_duration for NULL returns empty string", {
  expect_equal(main$format_duration(NULL), c(""))
})

[vituri]

Can you give me more details on how to reproduce this problem? I created a teste dir and the following file inside it:

# View: Shiny modules and related code.
# https://go.appsilon.com/rhino-project-structure
box::use(shiny)

# a
# b
1+1

Running box.linters::style_box_use_dir('teste') changed the initial file to

# View: Shiny modules and related code.
# https://go.appsilon.com/rhino-project-structure
box::use(
  shiny,
)

# a
# b
1+1

I added another file with the following content:

# View: Shiny modules and related code.
# https://go.appsilon.com/rhino-project-structure

# this file only contains comments!




# with spaces!

which was not modified with box.linters::style_box_use_dir('teste').

[jakubnowicki]

For most cases, it seems solved. The one that I recently found is a case when there are no empty lines at all.
This:

box::use(
  app/main,
)
context("Test main$format_duration()")
test_that("format_duration for NULL returns empty string", {
  expect_equal(main$format_duration(NULL), c(""))
})

Is changed into this:

box::use(
  app/main,
)

NA
NA
NA
NA

[vituri]

I added the following two tests in #155 and fixed the line where there was a NA appearing

test_that("style_box_use_file() works with no empty lines", {
  to_style <- "box::use(
  cli,
)
1+1
sin(1)"

  expected_styled <- c("box::use(", "  cli,", ")", "", "1+1", "sin(1)")
  withr::with_tempdir({
    xfun::write_utf8(to_style, "app_1.R")

    suppressWarnings(style_box_use_file("app_1.R"))

    result_styled <- xfun::read_utf8("app_1.R")

    expect_identical(result_styled, expected_styled)
  })



  to_style <- "box::use(
  cli,
)

1+1
sin(1)"

  expected_styled <- c("box::use(", "  cli,", ")", "", "1+1", "sin(1)")
  withr::with_tempdir({
    xfun::write_utf8(to_style, "app_1.R")

    suppressWarnings(style_box_use_file("app_1.R"))

    result_styled <- xfun::read_utf8("app_1.R")

    expect_identical(result_styled, expected_styled)
  })
})

The pull request is blocked by codecov because the new linter version complains about explicit returns; so I had to remove return calls in other parts of the code just to pass the tests (but since I changed other parts that were not covered by tests, codecov is complaining too :( )