expand tilde in CacheFile (#72)

* feat expand tilde in CacheFile

* add unit test

* refactor

* fix CompletionFilePath

---------

Co-authored-by: yokomotod <yokomotod@gmail.com>

cmd/root.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"path/filepath"
+	"strings"
 
 	"github.com/mitchellh/go-homedir"
 	"github.com/rs/zerolog"
@@ -71,6 +73,20 @@ func initConfig() {
 		os.Exit(1)
 	}
 
+	realCacheFile, err := realPath(config.CacheFile)
+	if err != nil {
+		fmt.Println("Failed to expand Cache File Path:", config.CacheFile)
+		os.Exit(1)
+	}
+	config.CacheFile = realCacheFile
+
+	realCompletionFilePath, err := realPath(config.CompletionFilePath)
+	if err != nil {
+		fmt.Println("Failed to expand Completion File Path:", config.CompletionFilePath)
+		os.Exit(1)
+	}
+	config.CompletionFilePath = realCompletionFilePath
+
 	logOutput() // set log level
 }
 
@@ -84,6 +100,19 @@ func logOutput() {
 	}
 }
 
+func realPath(filename string) (string, error) {
+	if !strings.HasPrefix(filename, "~/") {
+		return filename, nil
+	}
+
+	userDir, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(userDir, filename[2:]), nil
+}
+
 func init() {
 	cobra.OnInitialize(initConfig)
 	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.bqiam.toml)")

cmd/root_test.go

@@ -0,0 +1,45 @@
+package cmd
+
+import (
+	"os"
+	"path"
+	"testing"
+)
+
+func TestRealPath(t *testing.T) {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatalf("failed to get home directory: %v", err)
+	}
+
+	cases := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name:  "tilda",
+			input: "~/.bqiam-cache-file.toml",
+			want:  path.Join(homeDir, ".bqiam-cache-file.toml"),
+		},
+		{
+			name:  "relative",
+			input: ".bqiam-cache-file.toml",
+			want:  ".bqiam-cache-file.toml",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			got, err := realPath(c.input)
+
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+
+			if got != c.want {
+				t.Errorf("got: %s, want: %s", got, c.want)
+			}
+		})
+	}
+}