bugfixes nov2025 pt3 (#6)

* Minor improvements.
* DRY the codebase.
* Add version checker / updater.

internal/version/checker_test.go

@@ -0,0 +1,90 @@
+package version
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNormalizeVersion(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"v1.0.0", "1.0.0"},
+		{"1.0.0", "1.0.0"},
+		{"  v2.1.3  ", "2.1.3"},
+		{"V1.0.0", "1.0.0"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			result := normalizeVersion(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestParseVersion(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected []int
+	}{
+		{"1.0.0", []int{1, 0, 0}},
+		{"2.1.3", []int{2, 1, 3}},
+		{"1.0", []int{1, 0}},
+		{"10.20.30", []int{10, 20, 30}},
+		{"1.0.0-beta", []int{1, 0, 0}},
+		{"1.0.0-rc1", []int{1, 0, 0}},
+		{"1.0.0+build123", []int{1, 0, 0}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			result := parseVersion(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestIsNewerVersion(t *testing.T) {
+	tests := []struct {
+		name     string
+		latest   string
+		current  string
+		expected bool
+	}{
+		{"major version bump", "2.0.0", "1.0.0", true},
+		{"minor version bump", "1.1.0", "1.0.0", true},
+		{"patch version bump", "1.0.1", "1.0.0", true},
+		{"same version", "1.0.0", "1.0.0", false},
+		{"current is newer major", "1.0.0", "2.0.0", false},
+		{"current is newer minor", "1.0.0", "1.1.0", false},
+		{"current is newer patch", "1.0.0", "1.0.1", false},
+		{"multi-digit versions", "1.10.0", "1.9.0", true},
+		{"longer version is newer", "1.0.1", "1.0", true},
+		{"shorter version is older", "1.0", "1.0.1", false},
+		{"complex comparison", "2.1.3", "2.1.2", true},
+		{"real world example", "0.2.0", "0.1.0", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isNewerVersion(tt.latest, tt.current)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestUpdateInfo_FormatUpdateMessage(t *testing.T) {
+	info := &UpdateInfo{
+		CurrentVersion: "0.1.0",
+		LatestVersion:  "0.2.0",
+		ReleaseURL:     "https://github.com/nvm/kportal/releases/tag/v0.2.0",
+	}
+
+	msg := info.FormatUpdateMessage()
+	assert.Contains(t, msg, "0.2.0")
+	assert.Contains(t, msg, "0.1.0")
+	assert.Contains(t, msg, "https://github.com/nvm/kportal/releases/tag/v0.2.0")
+}