feat: gamemaster

gamemaster/internal/domain/engineversion/semver.go

@@ -0,0 +1,60 @@
+package engineversion
+
+import (
+	"fmt"
+	"strings"
+
+	"golang.org/x/mod/semver"
+)
+
+// ParseSemver normalises version into the canonical "vMAJOR.MINOR.PATCH"
+// form expected by `golang.org/x/mod/semver` and reports a wrapped
+// ErrInvalidSemver when the resulting string is not a valid full semver.
+//
+// Whitespace is trimmed; a missing leading "v" is added before the
+// validity check so callers may pass either "1.2.3" or "v1.2.3". The
+// stripped base must carry exactly three dot-separated numeric
+// components — `golang.org/x/mod/semver` accepts shortened forms such
+// as "v1" or "v1.2", but the engine-version registry requires the full
+// triple, so this function rejects anything narrower.
+func ParseSemver(version string) (string, error) {
+	candidate := strings.TrimSpace(version)
+	if candidate == "" {
+		return "", fmt.Errorf("%w: empty", ErrInvalidSemver)
+	}
+	if !strings.HasPrefix(candidate, "v") {
+		candidate = "v" + candidate
+	}
+	if !semver.IsValid(candidate) {
+		return "", fmt.Errorf("%w: %q", ErrInvalidSemver, version)
+	}
+
+	base := candidate
+	if i := strings.IndexAny(base, "-+"); i >= 0 {
+		base = base[:i]
+	}
+	if strings.Count(base, ".") != 2 {
+		return "", fmt.Errorf(
+			"%w: %q (need vMAJOR.MINOR.PATCH)",
+			ErrInvalidSemver, version,
+		)
+	}
+	return candidate, nil
+}
+
+// IsPatchUpgrade reports whether next is a same-major.minor upgrade of
+// current. Both inputs are parsed through ParseSemver so callers may
+// pass either bare or `v`-prefixed forms. A wrapped ErrInvalidSemver is
+// returned when either argument fails to parse; the boolean result is
+// undefined in that case.
+func IsPatchUpgrade(current, next string) (bool, error) {
+	curr, err := ParseSemver(current)
+	if err != nil {
+		return false, fmt.Errorf("current: %w", err)
+	}
+	nxt, err := ParseSemver(next)
+	if err != nil {
+		return false, fmt.Errorf("next: %w", err)
+	}
+	return semver.MajorMinor(curr) == semver.MajorMinor(nxt), nil
+}