Keep-a-Changelog Entry Header in GO
Match Keep-a-Changelog style version headers like `## [1.2.3] - 2024-01-15` or `## 2.0.0`.
Try it in the GO tester →Pattern
regexGO
^##\s+\[?([\w.\-]+)\]?(?:\s*-\s*(\d{4}-\d{2}-\d{2}))? (flags: gm)Go (RE2) code
goGo
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`(?m)^##\s+\[?([\w.\-]+)\]?(?:\s*-\s*(\d{4}-\d{2}-\d{2}))?`)
input := `## [1.2.3] - 2024-01-15\n## [Unreleased]`
for _, match := range re.FindAllString(input, -1) {
fmt.Println(match)
}
}Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.
How the pattern works
^## matches the markdown H2 marker. \s+ requires whitespace. \[? optionally matches an opening bracket. ([\w.\-]+) captures the version (semver, calendar version, or label like `Unreleased`). \]? optionally matches the closing bracket. (?:\s*-\s*(\d{4}-\d{2}-\d{2}))? optionally captures an ISO date.
Examples
Input
## [1.2.3] - 2024-01-15\n## [Unreleased]Matches
## [1.2.3] - 2024-01-15## [Unreleased]
Input
## 2.0.0 - 2025-12-25Matches
## 2.0.0 - 2025-12-25
Input
# TitleNo match
—