# Logging Unapproved Package and Function Use

# Why would I use this feature?

The main use case of this feature is to support traceability of package and function use within a validated environment.

Following the guidance outlined in A Risk-Based Approach for Assessing R Package Accuracy within a Validated Infrastructure, packages are selected to support use cases, risk is assessed and mitigated, and packages are included in your validated environment for use. Section 4.3 of this paper nicely outlines the need to trace what is used and the need to identify package and function use where risk was not assessed for direct use within the validated environment.

> 4.3. Traceability

> “One of the core concepts presented in this paper is that Imports are not typically loaded by users and need not therefore be directly risk-assessed. If adopting this risk-based approach then measures need to be taken to ensure that users do not directly load the Package Imports. It is suggested that this is handled mainly through process, although tools could be developed to check using sessionInfo or devtools::session_info that check the loaded packages against packages lists of Intended for Use and Imports. In any case the use of these tools within a standard, logged, workflow is highly recommended to ensure traceability of the work.”

{logrx} provides you this tool! It even goes a step further by not just logging the packages you’ve use, but it will log use at a function level. This gives you the flexibility of assessing the risk of functions and approving functions, rather than having to assess the risk of the entire package for use within your validated environment.

# How do I use this feature?

## 1. Create a named list

The named list contains the functions approved for use for each package. If all functions for a package are approved for use, list “All”.

    approved_pkgs <- list(base = "mean",
                          dplyr = "All")
    approved_pkgs
    #> $base
    #> [1] "mean"
    #>
    #> $dplyr
    #> [1] "All"

## 2. Build `approved.rds`

Pass the named list through `build_approved()` to build your tibble. We create a temp directory to save this for illustration.

    build_approved(approved_pkgs)
    #> # A tibble: 294 × 2
    #>    function_name         library
    #>    <chr>                 <chr>
    #>  1 mean                  package:base
    #>  2 slice_max             package:dplyr
    #>  3 expr                  package:dplyr
    #>  4 src                   package:dplyr
    #>  5 db_desc               package:dplyr
    #>  6 group_by_drop_default package:dplyr
    #>  7 db_commit             package:dplyr
    #>  8 coalesce              package:dplyr
    #>  9 data_frame            package:dplyr
    #> 10 summarize_if          package:dplyr
    #> # ℹ 284 more rows

## 3. Save as `approved.rds`

You can use the `file` argument in `build_approved()` to save `approved.rds` instead of returning the tibble.

    dir <- tempdir()

    build_approved(approved_pkgs, file = file.path(dir, "approved.rds"))

## 4. Update the `logrx.approved` option

Update the `logrx.approved` option to point to your `approved.rds` location. We recommend setting this in your `.Rprofile`.

    options(log.rx.approved = file.path(dir, "approved.rds"))

## 5. You’re done. Let’s axecute!

`logrx` will take it from there. When each program is executed, packages and functions will be compared to `approved.rds` and if any unapproved use is found, it will be logged within the “Unapproved Package and Functions” section of the log file.

# Example

Let’s write a simple script summarizing mean mpg from mtcars. We save this as `mpg.R` in the temporary directory `dir` and `axecute()` it.

    library(dplyr, warn.conflicts = FALSE)

    results <- mtcars %>%
       group_by(cyl) %>%
       summarize(mean = mean(mpg)) %>%
       mutate(label = "Mean MPG")

    results %>%
       tidyr::pivot_wider(names_from = cyl, values_from = mean, id_cols = label)
    #> # A tibble: 1 × 4
    #>   label      `4`   `6`   `8`
    #>   <chr>    <dbl> <dbl> <dbl>
    #> 1 Mean MPG  26.7  19.7  15.1

Here we have the log elements for “Used Package and Functions” and “Unapproved Package and Functions”. We can see we used `library()` from `package:base` and `pivot_wider` from `package:tidyr`. We did not include the base library or tidyr functions in our approved list, so this has been logged!

    #> --------------------------------------------------------------------------------
    #> -                          Used Package and Functions                          -
    #> --------------------------------------------------------------------------------
    #> {package:base} library, mean
    #> {package:dplyr} %>%, group_by, summarize, mutate
    #> {package:tidyr} pivot_wider
    #> --------------------------------------------------------------------------------
    #> -                       Unapproved Package and Functions                       -
    #> --------------------------------------------------------------------------------
    #> {package:base} library
    #> {package:tidyr} pivot_wider

# A Few Words of Caution

All packages should be attached at the top of the script to set a consistent `?base::searchpaths()` throughout the entire script. This will ensure the functions you use in your script are linked to the correct package. A lint feature is available to test your scripts follow this best practice.

Some functions are stored within a list, for example `knitr::opts_chunck$get()` and `knitr::opts_current$get()`. We do not currently identify `get()` as a knitr function since it is not exported.