R: Evaluate a promise, capturing all types of output.

evaluate_promise {testthat} | R Documentation

## Evaluate a promise, capturing all types of output.

### Description

These functions allow you to capture the side-effects of a function call including printed output, messages and warnings. They are used to evaluate code for `expect_output`, `expect_message`, `expect_warning`, and `expect_silent`.

### Usage

    evaluate_promise(code, print = FALSE)

    capture_messages(code)

    capture_warnings(code)

    capture_output(code, print = FALSE)

### Arguments

`code` | Code to evaluate. This should be an unevaluated expression.
`print` | If `TRUE` and the result of evaluating `code` is visible this will print the result, ensuring that the output of printing the object is included in the overall output

### Value

A list containing

`result` | The result of the function
`output` | A string containing all the output from the function
`warnings` | A character vector containing the text from each warning
`messages` | A character vector containing the text from each message

### Examples

    evaluate_promise({
      print("1")
      message("2")
      warning("3")
      4
    })

[Package testthat version 1.0.2 Index]