fix: prepare Tend preview 2

Publish the reviewed version identity fix and mark preview 1 withdrawn.\n\nPrivate-Source-Commit: 9907afdfa18099ac488fe4011291ea454036435a\nPrivate-Source-Tree: 3a5e666dd6a0c69a07f7804612c8e3dc3474966a\nHimesan-Output-Permission: v1.0\nAI-Assistance: OpenAI Codex assisted implementation and review.

Signed-off-by: Cole Speelman <crspeelman@gmail.com>

internal/version/version.go

@@ -2,8 +2,81 @@
 
 package version
 
+import (
+	"regexp"
+	"runtime/debug"
+	"strings"
+)
+
+const developmentVersion = "v0.1.0-dev"
+
 var (
-	Version = "v0.1.0-dev"
+	Version = developmentVersion
 	Commit  = "unknown"
 	Date    = "unknown"
 )
+
+var (
+	taggedVersionPattern       = regexp.MustCompile(`^v(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?$`)
+	pseudoVersionSuffixPattern = regexp.MustCompile(`(?:^|[.-])(?:0\.)?[0-9]{14}-[0-9a-f]{12,}$`)
+)
+
+func init() {
+	information, ok := debug.ReadBuildInfo()
+	if !ok {
+		return
+	}
+	Version = selectVersion(Version, information.Main.Version)
+	for _, setting := range information.Settings {
+		switch setting.Key {
+		case "vcs.revision":
+			if Commit == "unknown" && setting.Value != "" {
+				Commit = setting.Value
+			}
+		case "vcs.time":
+			if Date == "unknown" && setting.Value != "" {
+				Date = setting.Value
+			}
+		}
+	}
+}
+
+func selectVersion(linkerValue, moduleVersion string) string {
+	if linkerValue != developmentVersion {
+		return linkerValue
+	}
+	moduleVersion = strings.TrimSpace(moduleVersion)
+	if !isTaggedVersion(moduleVersion) {
+		return linkerValue
+	}
+	return moduleVersion
+}
+
+func isTaggedVersion(value string) bool {
+	matches := taggedVersionPattern.FindStringSubmatch(value)
+	if matches == nil {
+		return false
+	}
+	prerelease := matches[1]
+	if pseudoVersionSuffixPattern.MatchString(prerelease) {
+		return false
+	}
+	for _, identifier := range strings.Split(prerelease, ".") {
+		if len(identifier) > 1 && identifier[0] == '0' && allDecimal(identifier) {
+			return false
+		}
+	}
+	return true
+}
+
+func allDecimal(value string) bool {
+	if value == "" {
+		return false
+	}
+	for _, character := range value {
+		if character < '0' || character > '9' {
+			return false
+		}
+	}
+	return true
+}

internal/version/version_test.go

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+package version
+
+import "testing"
+
+func TestSelectVersion(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name, linker, module, want string
+	}{
+		{"local build", developmentVersion, "(devel)", developmentVersion},
+		{"missing build info", developmentVersion, "", developmentVersion},
+		{"preview one install", developmentVersion, "v0.1.0-preview.1", "v0.1.0-preview.1"},
+		{"preview two install", developmentVersion, "v0.1.0-preview.2", "v0.1.0-preview.2"},
+		{"release install", developmentVersion, "v1.0.0", "v1.0.0"},
+		{"linker override", "v0.1.0-preview.2", "(devel)", "v0.1.0-preview.2"},
+		{"pseudo version", developmentVersion, "v0.0.0-20260814120000-0123456789ab", developmentVersion},
+		{"pseudo after release", developmentVersion, "v0.1.1-0.20260814120000-0123456789ab", developmentVersion},
+		{"build metadata", developmentVersion, "v0.1.0+dirty", developmentVersion},
+		{"leading zero release", developmentVersion, "v00.1.0", developmentVersion},
+		{"leading zero prerelease", developmentVersion, "v0.1.0-preview.02", developmentVersion},
+	}
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+			if got := selectVersion(test.linker, test.module); got != test.want {
+				t.Fatalf("selectVersion(%q, %q)=%q want %q", test.linker, test.module, got, test.want)
+			}
+		})
+	}
+}