Code coverage is the ratio of code lines kissed by a test vs. the total number of lines in your source files. This sounds meaningful, but isn't.

Rails Long Term Support

Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)

• Prevents you from data breaches and liability risks
• Upgrade at your own pace
• Works with modern Rubies

Read more Show archive.org snapshot

Total coverage additionally ignores whitespace and comments when computing the coverage ratio, which is what you want.