09-ci.Rmd

# Automated Testing {#travis}

Once we are in the habit of packaging our code and writing unit tests, we can start to use free online tools such as [Travis CI](https://travis-ci.org/), [Jenkins](https://jenkins.io/), or [Appveyor](https://www.appveyor.com/) to automatically test that our package of code builds, and that the tests we have written, pass.

These tools integrate with GitHub, so we can easily see when an update to the code has failed one of our tests. The green ticks in the box below show that our tests have passed for the given pull request.

```{r fig.align='center', echo=FALSE, include=identical(knitr:::pandoc_to(), 'html'), fig.link='https://gdsdata.blog.gov.uk/2017/03/27/reproducible-analytical-pipeline/'}
knitr::include_graphics('images/travis1.png', dpi = NA)
```

We can also look at our [test history](https://travis-ci.org/ukgovdatascience/eesectors/branches) on Travis CI, as in the screenshot below. From this we can see that our main workstream - the default branch - has been tested 619 times to date, the last of which was one day ago, and the previous five tests have all passed without problems.

```{r fig.align='center', echo=FALSE, include=identical(knitr:::pandoc_to(), 'html'), fig.link='https://gdsdata.blog.gov.uk/2017/03/27/reproducible-analytical-pipeline/'}
knitr::include_graphics('images/travis2.png', dpi = NA)
```