reproducible example to get number of counts of function runs in semi-recursive

example_recurse.R

# function where first calls another function, that in turn calls the first,
# but does so in a way that the second is not called again. I want to test
# how many times f1 and f2 get called under different conditions

f1 <- function(use_f2 = FALSE){
  if (use_f2) {
    f2()
  }
}

f2 <- function(){
  f1(use_f2 = FALSE)
}

function_counts <- new.env()
function_counts$f1 <- function_counts$f2 <- 0

trace(f1, tracer = quote(function_counts$f1 <- function_counts$f1 + 1), print = FALSE)
trace(f2, tracer = quote(function_counts$f2 <- function_counts$f2 + 1), print = FALSE)

f1()
function_counts$f1
function_counts$f2

function_counts$f1 <- function_counts$f2 <- 0
f1(TRUE)
function_counts$f1
function_counts$f2

function_counts$f1 <- function_counts$f2 <- 0
f2()
function_counts$f1
function_counts$f2

output.txt

> f1()
> function_counts$f1
[1] 1
> function_counts$f2
[1] 0
> 
> function_counts$f1 <- function_counts$f2 <- 0
> f1(TRUE)
> function_counts$f1
[1] 2
> function_counts$f2
[1] 1
> 
> function_counts$f1 <- function_counts$f2 <- 0
> f2()
> function_counts$f1
[1] 1
> function_counts$f2
[1] 1

Note that the custom environment is needed to assign into, as a variable in the global environment will not get updated.