Merge pull request exercism#151 from lcowell/master

Expand '~' to user home in config file path

Author: lcowell

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ----------------
 
+* [#151](https://github.com/exercism/cli/pull/151): Expand '~' in config path to home directory - @lcowell
 * Your contribution here
 
 ## v1.9.2 (Jan 11, 2015)

config/config.go

@@ -110,32 +110,43 @@ func (c *Config) Update(key, host, dir, xapi string) {
 	c.configure()
 }
 
+// Expand takes inputs for a config file location and builds an absolute path.
+func Expand(path, env, home string) string {
+	if path == "" {
+		path = env
+	}
+
+	if path != "" && path[0] == '~' {
+		path = strings.Replace(path, "~/", fmt.Sprintf("%s/", home), 1)
+	}
+
+	if path == "" {
+		path = filepath.Join(home, File)
+	}
+
+	return path
+}
+
 // Read loads the config from the stored JSON file.
 func (c *Config) Read(file string) error {
 	renameLegacy()
 
-	if file == "" {
-		file = os.Getenv(fileEnvKey)
+	home, err := c.homeDir()
+	if err != nil {
+		return err
 	}
 
-	if file == "" {
-		home, err := c.homeDir()
-		if err != nil {
-			return err
-		}
-		file = filepath.Join(home, File)
-	}
+	c.File = Expand(file, os.Getenv(fileEnvKey), home)
 
-	c.File = file
-	if _, err := os.Stat(file); err != nil {
+	if _, err := os.Stat(c.File); err != nil {
 		if os.IsNotExist(err) {
 			c.configure()
 			return nil
 		}
 		return err
 	}
 
-	f, err := os.Open(file)
+	f, err := os.Open(c.File)
 	if err != nil {
 		return err
 	}

config/config_test.go

@@ -42,6 +42,35 @@ func TestExpandHomeDir(t *testing.T) {
 	assert.Equal(t, "/home/alice/practice", c.Dir)
 }
 
+func TestExpandConfigPath(t *testing.T) {
+	testCases := []struct {
+		path   string
+		env    string
+		result string
+	}{
+		{
+			"path/to/config.json",
+			"",
+			"path/to/config.json",
+		},
+		{
+			"",
+			"~/config.json",
+			"/home/alice/config.json",
+		},
+		{
+			"",
+			"",
+			"/home/alice/.exercism.json",
+		},
+	}
+	home := "/home/alice"
+
+	for _, tt := range testCases {
+		assert.Equal(t, Expand(tt.path, tt.env, home), tt.result)
+	}
+}
+
 func TestSanitizeWhitespace(t *testing.T) {
 	c := &Config{
 		APIKey: "   abc123\n\r\n  ",