Linting bypass for cyclomatic complexity cases

[sigmafelix]

• Several functions, most of which are for download functions, are not expected to pass lint checks as there are many if ... else ... statements or methods::is calls, etc. To bypass this, one can manually wrap a function with # nolint start and # nolint end (Reference), for example:

Before

download_something <- function () {
    if (...) {download.file(...)} else { return(NULL) }
}

After

# nolint start
download_something <- function () {
    if (...) {download.file(...)} else { return(NULL) }
}
# nolint end

It should be noted that bypassing should be allowed to functions with cyclomatic complexity only. Codes in general should abide by the general style guidance from linters. To see whether there is cyclomatic complexity, please run linter this code in RStudio Addins > Lint current file

After linting, a tab named "Markers" will appear at the third quadrant (given that your RStudio is in default panel configurations).

[sigmafelix]

Relevant download functions in ./input/Rinput/download_functions got # nolint start and # nolint end in my working branch isong-calc-covar.

[sigmafelix]

This issue is moved to "Wiki" section.

[mitchellmanware]

@sigmafelix

Another way to implement #nolint on the data download functions is with a .lintr configuration file. The configuration file will allow us to "exclude" specific lines/sections of code in the download...data.R functions from one or more linters, in this case the cyclocomp_linter.

Using this method we can ensure that all other linters are applied to the download functions, and avoid potentially confusing #nolint start/end lines of code within the R/ folder.

I have explored the .lintr configuration file on branch mm_download_function_enhancements_1117, and applied it to the GEOS-CF, GMTED, and NCEP NARR data download functions.

https://cran.r-project.org/web/packages/lintr/vignettes/lintr.html

[sigmafelix]

@mitchellmanware Sounds good. I will delete the obsolete wiki page.