The importance of testing

Conventional wisdom states that the earlier a software bug is found, the easier it is to fix and the less impact and cost it is likely to have. Often referred to as a shift-left approach—in that given a process diagram moving from left to right in sequence, the further left you deal with an issue, the better—the idea is that by including robust and thorough testing in your DevOps workflow, you stand a much better chance of catching potential issues early. This approach applies not only to functional testing of your Salesforce changes but also to the security aspects of your design and development too—part of what has been dubbed DevSecOps in the wider IT industry.

If we look at the impact of testing in the context of our DORA metrics discussed in Chapter 2, we can easily see that testing directly impacts the CFR metric. Put simply, the more well tested your changes are, the less likely that errors are to be deployed into your later...