swirl (version 2.2.0)

omnitest: Test for a correct expression, a correct value, or both.

Description

Omnitest can test for a correct expression, a correct value, or both. In the case of values it is limited to testing for character or numerical vectors of length 1. For course authors only, omnitest is not exported.

Usage

omnitest(correctExpr = NULL, correctVal = NULL, strict = FALSE)

Arguments

correctExpr

the correct or expected expression as a string

correctVal

the correct value (numeric or character)

strict

a logical value indicating that the expression should be as expected even if the value is correct. If FALSE (the default) a correct value will pass the test even if the expression is not as expected, but a notification will be issued.

Examples

# Test that a user has chosen a correct menu item
  #
  omnitest(correctVal='Men in a college dorm.')

  # Test that a user has entered a correct number at the
  # command line
  #
  omnitest(correctVal=19)

  # Test that a user has entered a particular command
  #
  omnitest('myVar <- c(3, 5, 7)')

  # Test that a user has entered a command which computes
  # a specific value but perhaps in a different manner
  # than anticipated
  #
  omnitest('sd(x)^2', 5.95)
  #
  # If the user enters sd(x)*sd(x), rather than sd(x)^2, a notification
  # will be issued, but the test will not fail.

  # Test that a user has entered a command which computes
  # a specific value in a particular way
  #
  omnitest('sd(x)^2', 5.95, strict=TRUE)
  #
  # In this case, if the user enters sd(x)*sd(x) the test will fail.