Example of R CMD check No visible binding for global variable NOTE when defining a variable in a S3 generic and calling it in a method.

Install with:

# install.packages("devtools")
devtools::install_github("vgherard/globalReprex")

The function greet() is an S3 generic defined by:

# greet <- function(object) {
#         greeting <- "hola"
#         UseMethod("greet", object)
# }
# 
# greet.character <- function(object)
#         paste(greeting, object)

This works as expected:

library(globalReprex)
greet("you")

## [1] "hola you"

However R CMD check gives the following NOTE:

• greet.character: no visible binding for global variable ‘greeting’ Undefined global functions or variables: greeting