[LINT_BUG]: box_default_linters$box_usage_linter errors when it shouldn't

[SaintRod]

box.linters version

0.10.5

Sample source code to lint

box::use(
    here[here]
)

# fails
for (file in here()) {
  assign(
    x = paste0("path_", tolower(basename(file))),
    value = file,
    envir = .GlobalEnv
  )
  rm(file)
}

# succeeds
tmpFunc = function(name) paste0("path_", tolower(basename(name)))
for (file in here()) {
  assign(
    x = tmpFunc(file),
    value = file,
    envir = .GlobalEnv
  )
  rm(file)
}

Lint command used

box::use(
  box.linters[box_default_linters],
  here[here],
  lintr[lint],
)

lint(
  filename = here("test.r"),
  linters = box_default_linters$box_usage_linter
)

Lint result

Error: Linter 'box_usage_linter' failed in ./test.r: <text>:4:1: unexpected ','
3: "path_"
4: ,
   ^

Expected result

No error expected

[SaintRod]

PS. I'm not using box.linters with rhino

[radbasa]

assign(
  x = paste0("path_", tolower(basename(file))),
  value = file,
  envir = .GlobalEnv
)

This fails linting because the linter expects the value of x to be a character string. Because linting does static code analysis, it cannot and does not process or execute the paste() command to build the character string.

The other way you presented won't trigger a linting error, but it may cause linting errors further down your code. box_usage_linter() may complain about:

x <- path_some_file

As path_some_file was not defined previously. A different way to accomplish this might be to do the following:

file_paths <- list()
assign(
  x = file_paths[[tolower(basename(file))]],
  value = file,
  envir = .GlobalEnv
)

# This should be ok
foo <- file_paths$some_filename

[SaintRod]

Thanks @radbasa

This fails linting because the linter expects the value of x to be a character string. Because linting does static code analysis, it cannot and does not process or execute the paste() command to build the character string.

Is it possible for the linter to know that the output of paste() and paste0() is of class character? This way no code needs to be executed and the type requirement for the x arg in assign() is satisfied.