fix: Improvements to `starship configure` (#756)

- look for $VISUAL first, then $EDITOR, then the default
- panic if we can't find the home dir

src/configure.rs

@@ -1,7 +1,7 @@
 use std::env;
+use std::ffi::OsString;
 use std::process::Command;
 
-const UNKNOWN_CONFIG: &str = "<unknown config>";
 const STD_EDITOR: &str = "vi";
 
 pub fn edit_configuration() {
@@ -15,23 +15,14 @@ pub fn edit_configuration() {
 }
 
 fn get_editor() -> String {
-    match env::var("EDITOR") {
-        Ok(val) => val,
-        Err(_) => STD_EDITOR.to_string(),
-    }
+    let editor = env::var("VISUAL").or_else(|_| env::var("EDITOR"));
+    editor.unwrap_or_else(|_| STD_EDITOR.to_string())
 }
 
-fn get_config_path() -> String {
-    let home_dir = dirs::home_dir();
-
-    if home_dir.is_none() {
-        return UNKNOWN_CONFIG.to_string();
-    }
-
-    let path = home_dir.unwrap().join(".config/starship.toml");
-
-    match path.to_str() {
-        Some(p) => String::from(p),
-        None => UNKNOWN_CONFIG.to_string(),
-    }
+fn get_config_path() -> OsString {
+    dirs::home_dir()
+        .expect("Couldn't find home directory")
+        .join(".config/starship.toml")
+        .as_os_str()
+        .to_owned()
 }