refactor: move things to packages (#39)

internal/versioning/semver.go

@@ -0,0 +1,110 @@
+package versioning
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/blang/semver/v4"
+
+	"github.com/apricote/releaser-pleaser/internal/commitparser"
+	"github.com/apricote/releaser-pleaser/internal/git"
+)
+
+var _ Strategy = SemVerNextVersion
+
+func SemVerNextVersion(r git.Releases, versionBump VersionBump, nextVersionType NextVersionType) (string, error) {
+	latest, err := parseSemverWithDefault(r.Latest)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse latest version: %w", err)
+	}
+
+	stable, err := parseSemverWithDefault(r.Stable)
+	if err != nil {
+		return "", fmt.Errorf("failed to parse stable version: %w", err)
+	}
+
+	// If there is a previous stable release, we use that as the version anchor. Falling back to any pre-releases
+	// if they are the only tags in the repo.
+	next := latest
+	if r.Stable != nil {
+		next = stable
+	}
+
+	switch versionBump {
+	case UnknownVersion:
+		return "", fmt.Errorf("invalid latest bump (unknown)")
+	case PatchVersion:
+		err = next.IncrementPatch()
+	case MinorVersion:
+		err = next.IncrementMinor()
+	case MajorVersion:
+		err = next.IncrementMajor()
+	}
+	if err != nil {
+		return "", err
+	}
+
+	switch nextVersionType {
+	case NextVersionTypeUndefined, NextVersionTypeNormal:
+		next.Pre = make([]semver.PRVersion, 0)
+	case NextVersionTypeAlpha, NextVersionTypeBeta, NextVersionTypeRC:
+		id := uint64(0)
+
+		if len(latest.Pre) >= 2 && latest.Pre[0].String() == nextVersionType.String() {
+			if latest.Pre[1].String() == "" || !latest.Pre[1].IsNumeric() {
+				return "", fmt.Errorf("invalid format of previous tag")
+			}
+			id = latest.Pre[1].VersionNum + 1
+		}
+
+		setPRVersion(&next, nextVersionType.String(), id)
+	}
+
+	return "v" + next.String(), nil
+}
+
+func BumpFromCommits(commits []commitparser.AnalyzedCommit) VersionBump {
+	bump := UnknownVersion
+
+	for _, commit := range commits {
+		entryBump := UnknownVersion
+		switch {
+		case commit.BreakingChange:
+			entryBump = MajorVersion
+		case commit.Type == "feat":
+			entryBump = MinorVersion
+		case commit.Type == "fix":
+			entryBump = PatchVersion
+		}
+
+		if entryBump > bump {
+			bump = entryBump
+		}
+	}
+
+	return bump
+}
+
+func setPRVersion(version *semver.Version, prType string, count uint64) {
+	version.Pre = []semver.PRVersion{
+		{VersionStr: prType},
+		{VersionNum: count, IsNum: true},
+	}
+}
+
+func parseSemverWithDefault(tag *git.Tag) (semver.Version, error) {
+	version := "v0.0.0"
+	if tag != nil {
+		version = tag.Name
+	}
+
+	// The lib can not handle v prefixes
+	version = strings.TrimPrefix(version, "v")
+
+	parsedVersion, err := semver.Parse(version)
+	if err != nil {
+		return semver.Version{}, fmt.Errorf("failed to parse version %q: %w", version, err)
+	}
+
+	return parsedVersion, nil
+}