Consolidate duplicate normalizeVersion functions into shared utility

- Move normalizeVersion to utils.NormalizeVersion for single source of truth
- Update agentupdate and dockeragent packages to use shared function
- Add 14 test cases for version normalization

This prevents bugs like issue #773 where a fix applied to one copy
but not the other caused an update loop.

internal/agentupdate/update.go

@@ -21,6 +21,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/rcourtman/pulse-go-rewrite/internal/utils"
 	"github.com/rs/zerolog"
 )
 
@@ -159,7 +160,7 @@ func (u *Updater) CheckAndUpdate(ctx context.Context) {
 	// Normalize both versions by stripping "v" prefix for comparison.
 	// Server returns version without prefix (e.g., "4.33.1"), but agent's
 	// CurrentVersion may include it (e.g., "v4.33.1") depending on build.
-	if normalizeVersion(serverVersion) == normalizeVersion(u.cfg.CurrentVersion) {
+	if utils.NormalizeVersion(serverVersion) == utils.NormalizeVersion(u.cfg.CurrentVersion) {
 		u.logger.Debug().Str("version", u.cfg.CurrentVersion).Msg("Agent is up to date")
 		return
 	}
@@ -440,11 +441,6 @@ func (u *Updater) performUpdate(ctx context.Context) error {
 	return nil
 }
 
-// normalizeVersion strips the "v" prefix from version strings for comparison.
-func normalizeVersion(version string) string {
-	return strings.TrimPrefix(strings.TrimSpace(version), "v")
-}
-
 // determineArch returns the architecture string for download URLs (e.g., "linux-amd64", "darwin-arm64").
 func determineArch() string {
 	os := runtime.GOOS

internal/agentupdate/update_test.go

@@ -5,6 +5,8 @@ import (
 	"path/filepath"
 	"runtime"
 	"testing"
+
+	"github.com/rcourtman/pulse-go-rewrite/internal/utils"
 )
 
 func TestDetermineArch(t *testing.T) {
@@ -398,10 +400,10 @@ func TestSymlinkResolution(t *testing.T) {
 }
 
 func TestNormalizeVersion(t *testing.T) {
-	if got := normalizeVersion("v4.33.1"); got != "4.33.1" {
-		t.Errorf("normalizeVersion(%q) = %q, want %q", "v4.33.1", got, "4.33.1")
+	if got := utils.NormalizeVersion("v4.33.1"); got != "4.33.1" {
+		t.Errorf("NormalizeVersion(%q) = %q, want %q", "v4.33.1", got, "4.33.1")
 	}
-	if got := normalizeVersion("4.33.1"); got != "4.33.1" {
-		t.Errorf("normalizeVersion(%q) = %q, want %q", "4.33.1", got, "4.33.1")
+	if got := utils.NormalizeVersion("4.33.1"); got != "4.33.1" {
+		t.Errorf("NormalizeVersion(%q) = %q, want %q", "4.33.1", got, "4.33.1")
 	}
 }

internal/dockeragent/agent.go

@@ -1618,7 +1618,7 @@ func (a *Agent) checkForUpdates(ctx context.Context) {
 	// Compare versions - normalize by stripping "v" prefix for comparison.
 	// Server returns version without prefix (e.g., "4.33.1"), but agent's
 	// Version may include it (e.g., "v4.33.1") depending on build.
-	if normalizeVersion(versionResp.Version) == normalizeVersion(Version) {
+	if utils.NormalizeVersion(versionResp.Version) == utils.NormalizeVersion(Version) {
 		a.logger.Debug().Str("version", Version).Msg("Agent is up to date")
 		return
 	}
@@ -1884,8 +1884,3 @@ func (a *Agent) selfUpdate(ctx context.Context) error {
 
 	return nil
 }
-
-// normalizeVersion strips the "v" prefix from version strings for comparison.
-func normalizeVersion(version string) string {
-	return strings.TrimPrefix(strings.TrimSpace(version), "v")
-}

internal/utils/helpers.go

@@ -41,3 +41,10 @@ func ParseBool(value string) bool {
 func GetenvTrim(key string) string {
 	return strings.TrimSpace(os.Getenv(key))
 }
+
+// NormalizeVersion strips the "v" prefix from version strings for comparison.
+// This normalizes versions like "v4.33.1" to "4.33.1" so that version strings
+// from different sources (agent vs server) can be compared consistently.
+func NormalizeVersion(version string) string {
+	return strings.TrimPrefix(strings.TrimSpace(version), "v")
+}

internal/utils/utils_test.go

@@ -280,3 +280,41 @@ func TestWriteJSONResponse_LargePayload(t *testing.T) {
 		t.Errorf("Decoded length = %d, want 1000", len(decoded))
 	}
 }
+
+func TestNormalizeVersion(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		// With v prefix
+		{"v4.33.1", "4.33.1"},
+		{"v1.0.0", "1.0.0"},
+		{"v0.0.1-rc1", "0.0.1-rc1"},
+
+		// Without v prefix
+		{"4.33.1", "4.33.1"},
+		{"1.0.0", "1.0.0"},
+		{"0.0.1-rc1", "0.0.1-rc1"},
+
+		// With whitespace
+		{" v4.33.1", "4.33.1"},
+		{"v4.33.1 ", "4.33.1"},
+		{" v4.33.1 ", "4.33.1"},
+		{"\tv4.33.1\n", "4.33.1"},
+
+		// Edge cases
+		{"", ""},
+		{"v", ""},
+		{" ", ""},
+		{"vv4.33.1", "v4.33.1"}, // Only removes one v
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.input, func(t *testing.T) {
+			result := NormalizeVersion(tc.input)
+			if result != tc.expected {
+				t.Errorf("NormalizeVersion(%q) = %q, want %q", tc.input, result, tc.expected)
+			}
+		})
+	}
+}