Function validateAndInit

rivermigrate/river_migrate.go:868–898

Validates and fully initializes a set of migrations to reduce the probability of configuration problems as new migrations are introduced. e.g. Checks for missing fields or accidentally duplicated version numbers from copy/pasta problems.

(versions []Migration)

// missing fields or accidentally duplicated version numbers from copy/pasta
// problems.
func validateAndInit(versions []Migration) map[int]Migration {
	lastVersion := 0
	migrations := make(map[int]Migration, len(versions))

	for _, versionBundle := range versions {
		if versionBundle.SQLDown == "" {
			panic(fmt.Sprintf("version bundle should specify Down: %+v", versionBundle))
		}
		if versionBundle.SQLUp == "" {
			panic(fmt.Sprintf("version bundle should specify Up: %+v", versionBundle))
		}
		if versionBundle.Version == 0 {
			panic(fmt.Sprintf("version bundle should specify Version: %+v", versionBundle))
		}

		if _, ok := migrations[versionBundle.Version]; ok {
			panic(fmt.Sprintf("duplicate version: %03d", versionBundle.Version))
		}
		if versionBundle.Version <= lastVersion {
			panic(fmt.Sprintf("versions should be ascending; current: %03d, last: %03d", versionBundle.Version, lastVersion))
		}
		if versionBundle.Version > lastVersion+1 {
			panic(fmt.Sprintf("versions shouldn't skip a sequence number; current: %03d, last: %03d", versionBundle.Version, lastVersion))
		}

		lastVersion = versionBundle.Version
		migrations[versionBundle.Version] = versionBundle
	}

	return migrations
}