add test for proof of fix

cobra/cmd/root_test.go

@@ -0,0 +1,72 @@
+package cmd
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	homedir "github.com/mitchellh/go-homedir"
+	"github.com/spf13/viper"
+)
+
+func TestConfigFileDefaultFormat(t *testing.T) {
+	var (
+		defaultConfigName        = ".cobra"
+		configFileTestSuffix     = ".test.bak"
+		testKey                  = "aKey"
+		testValue0               = "aValue0"
+		testValue1               = "aValue1"
+		defaultConfigFileContent = []byte(fmt.Sprintf(
+			"---\n%s:\n  - %s\n  - %s\n",
+			testKey, testValue0, testValue1,
+		))
+		home string
+		err  error
+	)
+
+	if home, err = homedir.Dir(); err != nil {
+		t.Fatalf("Error discovering home directory: %v", err)
+	}
+
+	configFilePath := filepath.Join(home, defaultConfigName)
+
+	// if file already exists, move to backup
+	if fileInfo, _ := os.Stat(configFilePath); fileInfo != nil {
+		configFilePathBackup := configFilePath + configFileTestSuffix
+		os.Remove(configFilePathBackup)
+		if err = os.Rename(configFilePath, configFilePathBackup); err != nil {
+			t.Fatalf("Error backing up existing config file '%v' :'%v'", configFilePath, err)
+		}
+		// defer moving backup back to original
+		defer func() {
+			os.Remove(configFilePath)
+			os.Rename(configFilePathBackup, configFilePath)
+		}()
+	}
+
+	// create test file
+	os.Remove(configFilePath)
+	ioutil.WriteFile(configFilePath, defaultConfigFileContent, 0666)
+	if _, err = os.Stat(configFilePath); os.IsNotExist(err) {
+		t.Fatalf("Expected to find file '%s', but got '%v'", configFilePath, err)
+	}
+
+	// attempt to use config file
+	initConfig()
+
+	result := viper.GetStringSlice(testKey)
+	expected := []string{testValue0, testValue1}
+	if len(result) != len(expected) {
+		t.Fatalf("Expected '%T' with %d elements, but got '%v'", expected, len(expected), result)
+	}
+	for i := range result {
+		if result[i] != expected[i] {
+			t.Fatalf("Expected '%v', but got '%v'", expected, result)
+		}
+	}
+
+	// delete test file
+	os.Remove(configFilePath)
+}