Check R code before running it — validate

Parses the code to catch syntax errors, and looks for calls to functions that are often risky, such as system(). It's a quick check, so code that can't run never reaches the child process.

Usage

validate_code(code)

Arguments

code: Character string of R code to validate.

Value

A list with components:

valid: Logical. TRUE if the code parses without error.
error: NULL on success, or a character string describing the parse error.
warnings: Character vector of warnings about risky-looking calls such as system() or .Internal(). Empty if there are none. The warnings don't block anything; the sandbox does that.

Details

The check for risky calls is only advice. It uses simple regular expressions, so it flags some harmless code and misses some risky code. What actually restricts files, network, and processes is the OS sandbox (Seatbelt or bwrap). Don't rely on this check to stop dangerous code.

Examples

# Valid code
result <- validate_code("1 + 1")
result$valid
#> [1] TRUE
# TRUE

# Syntax error
result <- validate_code("if (TRUE {")
result$valid
#> [1] FALSE
# FALSE
result$error
#> [1] "<text>:1:10: unexpected '{'\n1: if (TRUE {\n             ^"

# Warning about a risky call
result <- validate_code("system('ls')")
result$warnings
#> [1] "Code contains call to `system()` which may be restricted by the sandbox"