add test for config.randomString func

pkg/config/config.go

@@ -0,0 +1,54 @@
+package config
+
+import (
+	"math/rand"
+
+	"github.com/joho/godotenv"
+	"github.com/kelseyhightower/envconfig"
+	log "github.com/sirupsen/logrus"
+	"github.com/usefathom/fathom/pkg/datastore/sqlstore"
+)
+
+type Config struct {
+	Database *sqlstore.Config
+
+	Secret string
+}
+
+func Parse(file string) *Config {
+	var cfg Config
+	var err error
+
+	if file != "" {
+		err = godotenv.Load(file)
+		if err != nil && file != ".env" {
+			log.Fatalf("error parsing config file: %s", err)
+		}
+	}
+
+	err = envconfig.Process("Fathom", &cfg)
+	if err != nil {
+		log.Fatalf("error parsing config from environment values: %s", err)
+	}
+
+	// alias sqlite to sqlite3
+	if cfg.Database.Driver == "sqlite" {
+		cfg.Database.Driver = "sqlite3"
+	}
+
+	// if secret key is empty, use a randomly generated one
+	if cfg.Secret == "" {
+		cfg.Secret = randomString(40)
+	}
+
+	return &cfg
+}
+
+func randomString(len int) string {
+	bytes := make([]byte, len)
+	for i := 0; i < len; i++ {
+		bytes[i] = byte(65 + rand.Intn(25)) //A=65 and Z = 65+25
+	}
+
+	return string(bytes)
+}

pkg/config/config_test.go

@@ -0,0 +1,34 @@
+package config
+
+import (
+	"os"
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+	// empty config, should not fatal
+	cfg := Parse("")
+	if cfg.Secret == "" {
+		t.Errorf("expected secret, got empty string")
+	}
+
+	os.Setenv("FATHOM_DATABASE_DRIVER", "sqlite")
+	cfg = Parse("")
+	if cfg.Database.Driver != "sqlite3" {
+		t.Errorf("expected %#v, got %#v", "sqlite3", cfg.Database.Driver)
+	}
+
+}
+
+func TestRandomString(t *testing.T) {
+	r1 := randomString(10)
+	r2 := randomString(10)
+
+	if r1 == r2 {
+		t.Errorf("expected two different strings, got %#v", r1)
+	}
+
+	if l := len(r1); l != 10 {
+		t.Errorf("expected string of length %d, got string of length %d", 10, l)
+	}
+}