##Unit Tests for Programming Assignment 1

This project is an implementation of testthat unit tests for the Coursera R Programming course Assignment 1. The testthat package was written by Hadley Wickham to enable unit testing of the 'stringr' string manipulation package during development. The unit tests implement the examples given in the Instructions for Programming Assignment 1.

---|--------------------|------------------------------|--------------------------------------------- 1 | pollutantmean | Calculate the mean of a pollutant | test-pollutantmean.r 2 | complete | Report the number of complete cases | test-complete.r 3 | corr | Calculate the correlation between two pollutants | test-corr.r

1. source the script for the assignment into your R working environment.

• E.g., > source("pollutantmean.R")

2. source the matching testthat script into your environment.

• > source("test-pollutantmean.r")
• >

3. Notice how unobtrusive testthat is, if there is no error.

You can also run scripts using the test_file function.

> test_file("test-pollutantmean.r")
Calculate the mean of a pollutant across a specified list of monitors : .....

> 

A little more verbose, but still pretty quiet.

For more information on the testthat package see,

• testthat: Get Started with Testing, R Journal, June 2011.
• CRAN package, testthat