The goal of {depcheck} is to provide an overview of the R packages used within a project, finds which functions have been called from the loaded packages, and includes a warning for any package that is seldom/never utilised.

devtools::install_github("ashbaldry/depcheck")

The 3 main functions in {depcheck}:

• checkPackageDependencyUse() will read the Depends and Imports fields from the DESCRIPTION file, and look in the R subdirectory for package usage.
• checkShinyDependencyUse() will check all relevant R files for library, require, requireNamespace and :: calls to find all packages used, and then run a check on total usage of those packages.
• checkProjectDependencyUse() is a more generic version of checkShinyDependencyUse() and will recursively search all R files in a project directory for packages and their use.

When printing the results, there are a few options to adjust what is classified as "low usage":

• warn_percent_usage, the minimum percentage of functions used before the warning flag is produced
• warn_number_usage, the minimum number of functions used before the warning flag is produced
• ignore_low_usage_packages, if already aware of a package that is rarely used, then it can be included here so it won't be printed as low usage

If a package fails all 3 conditions, then it will be included in the list of under utilised packages.

NB Base R packages, such as {utils} and {stats} will automatically be excluded from the low usage packages

project_dependencies <- checkShinyDependencyUse("../reddit-analysis-app") # ashbaldry/reddit-analysis-app
summary(project_dependencies)
# Number of Declared Packages: 14
# Total Number of Dependencies: 85
# Declared Packages: utils, glue, httr, highcharter, scales, shiny.semantic, htmlwidgets, stringi, 
# quanteda, R6, data.table, shiny, promises, magrittr
# Function usage for 'glue', 'htmlwidgets', 'stringi', 'magrittr' are below the specified thresholds. 
# Print individual package summaries to check if packages can be removed

summary(project_dependencies$glue)
# Package: 'glue'
# Package Dependencies: 0
# Package Usage: 1 / 16 (6%)
# Functions Used: glue
# Function usage for 'glue' is below the specified thresholds. Consider copying used function to reduce dependencies