support multi-module (#4)

* add multimodule
* re-package modules

server/internal/generator/planet_test.go

@@ -0,0 +1,30 @@
+package generator_test
+
+import (
+	"regexp"
+	"testing"
+
+	g "github.com/iliadenisov/galaxy/server/internal/generator"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPlanetRandomName(t *testing.T) {
+	re, err := regexp.Compile(`^([a-zA-Z]+)-(\d{4})-(\d{4})$`)
+	assert.NoError(t, err)
+	if err != nil {
+		return
+	}
+	for _, pc := range []g.PlanetClass{g.PlanetClassHW, g.PlanetClassDW, g.PlanetClassGiant, g.PlanetClassBig, g.PlanetClassNormal, g.PlanetClassRich, g.PlanetClassAsterioid} {
+		t.Run(string(pc), func(t *testing.T) {
+			name := g.NewPlanet(pc, g.Coordinate{0, 0}, 0, 0).RandomName()
+			g := re.FindStringSubmatch(name)
+			assert.NotNilf(t, g, "cannot parse: %q", name)
+			if g == nil {
+				return
+			}
+			assert.Equalf(t, 4, len(g), "regexp groups")
+			assert.Equal(t, string(pc), g[1])
+			assert.NotEqual(t, g[2], g[3])
+		})
+	}
+}