fix: Fix tests and make the new config work properly

* Using the `reflect` package to set automatic defaults for all config
  values
* Because of the above, we should be able to load all config values from
  the environment
* The `ConfigFileNotFoundError` does not work as expected when
  `SetConfigFile` is used, so I created a utility function instead. ref: spf13/viper#1491

config/config.go

@@ -2,6 +2,8 @@ package config
 
 import (
 	"fmt"
+	"os"
+	"reflect"
 	"strings"
 
 	"github.com/underdog-tech/vulnbot/logger"
@@ -28,38 +30,55 @@ type Config struct {
 	Team                  []TeamConfig
 }
 
+func fileExists(fname string) bool {
+	if _, err := os.Stat(fname); err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return true
+}
+
 func GetUserConfig(configFile string) (Config, error) {
 	log := logger.Get()
 
 	userCfg := Config{}
 
-	// Set up env var overrides
-	replacer := strings.NewReplacer("-", "_")
-	viper.SetEnvKeyReplacer(replacer)
-	viper.SetEnvPrefix("vulnbot")
-	viper.AutomaticEnv()
+	// Use reflection to register all config fields in Viper to set up defaults
+	cfgFields := reflect.ValueOf(userCfg)
+	cfgType := cfgFields.Type()
+
+	for i := 0; i < cfgFields.NumField(); i++ {
+		viper.SetDefault(cfgType.Field(i).Name, cfgFields.Field(i).Interface())
+	}
 
 	// Load the main config file
+	if !fileExists(configFile) {
+		log.Fatal().Str("config", configFile).Msg("Config file not found.")
+	}
 	viper.SetConfigFile(configFile)
 	if err := viper.ReadInConfig(); err != nil {
-		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
-			log.Fatal().Str("config", configFile).Err(err).Msg("Config file not found.")
-		} else {
-			log.Fatal().Err(err).Msg("Error reading config file.")
-		}
+		log.Fatal().Err(err).Msg("Error reading config file.")
 	}
-	viper.Unmarshal(&userCfg)
 
 	// (Optionally) Load a .env file
-	viper.SetConfigFile("./.env")
-	viper.SetConfigType("env")
-	if err := viper.ReadInConfig(); err != nil {
-		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
-			log.Warn().Msg("No .env file found; not loaded.")
-		} else {
+	if fileExists("./.env") {
+		viper.SetConfigFile("./.env")
+		viper.SetConfigType("env")
+		if err := viper.ReadInConfig(); err != nil {
 			log.Error().Err(err).Msg("Error loading .env file.")
 		}
+	} else {
+		log.Warn().Msg("No .env file found; not loaded.")
 	}
+
+	// Set up env var overrides
+	replacer := strings.NewReplacer("-", "_")
+	viper.SetEnvKeyReplacer(replacer)
+	viper.SetEnvPrefix("vulnbot")
+	viper.AutomaticEnv()
+
+	// Finally, copy all loaded values into the config object
 	viper.Unmarshal(&userCfg)
 
 	return userCfg, nil

config/config_test.go

@@ -69,38 +69,29 @@ func getCurrentDir() (string, error) {
 	return cwd, nil
 }
 
-func TestLoadConfig(t *testing.T) {
-	expectedSlackChannel := "testing_slack_channel"
+func TestGetUserConfigFromFile(t *testing.T) {
 	currentDir, err := getCurrentDir()
-	if err != nil {
-		assert.Error(t, err)
-	}
+	assert.Nil(t, err)
 	testDataPath := filepath.Join(currentDir, "/testdata/test_config.toml")
-
-	var cfg config.Config
-	_ = config.LoadConfig(config.ViperParams{
-		Output:     &cfg,
-		ConfigPath: &testDataPath,
-	})
-
-	assert.IsType(t, config.Config{}, cfg)
-	assert.Equal(t, expectedSlackChannel, cfg.Default_slack_channel)
+	cfg, err := config.GetUserConfig(testDataPath)
+	assert.Nil(t, err)
+	assert.Equal(t, "testing_slack_channel", cfg.Default_slack_channel)
+	assert.Equal(t, []config.EcosystemConfig{{Label: "Go", Slack_emoji: ":golang:"}}, cfg.Ecosystem)
 }
 
-func TestLoadEnv(t *testing.T) {
-	expectedSlackAuthToken := "testing"
-	currentDir, err := getCurrentDir()
-	if err != nil {
-		assert.Error(t, err)
-	}
-	testDataPath := filepath.Join(currentDir, "/testdata/config.env")
+func TestGetUserConfigFromEnv(t *testing.T) {
+	t.Setenv("VULNBOT_DISABLE_SLACK", "1")
+	t.Setenv("VULNBOT_GITHUB_ORG", "hitchhikers")
+	// This should override the config file
+	t.Setenv("VULNBOT_DEFAULT_SLACK_CHANNEL", "other_slack_channel")
 
-	var env config.Env
-	_ = config.LoadEnv(config.ViperParams{
-		EnvFileName: &testDataPath,
-		Output:      &env,
-	})
+	currentDir, err := getCurrentDir()
+	assert.Nil(t, err)
+	testDataPath := filepath.Join(currentDir, "/testdata/test_config.toml")
+	cfg, err := config.GetUserConfig(testDataPath)
+	assert.Nil(t, err)
 
-	assert.IsType(t, config.Env{}, env)
-	assert.Equal(t, expectedSlackAuthToken, env.SlackAuthToken)
+	assert.True(t, cfg.Disable_slack)
+	assert.Equal(t, "hitchhikers", cfg.Github_org)
+	assert.Equal(t, "other_slack_channel", cfg.Default_slack_channel)
 }