A regular expression is a pattern notation for matching and extracting text according to character and sequence rules. In Go, the regexp package supports tests such as validating identifiers produced by randomized code. section 8.5.2 section 8.7
Finding and normalizing a generated ID
To test JSON containing a random alphanumeric ID, compile `.+"id":"([a-zA-Z0-9]+)".+`, call `FindStringSubmatch`, verify that one capture was found, replace the captured value with a fixed string, and compare the normalized JSON. The character class permits uppercase letters, lowercase letters, and digits; the parentheses capture the ID. section 8.5.2
Use regular expressions to:
- Validate that an identifier contains the expected number and kinds of characters. section 8.5.2
- Match variable output without requiring randomized values to be identical across test runs. section 8.5.2
- Document complicated patterns with comments because compact expressions can become difficult to read. section 8.7
