Open user default editor if available

crates/cli/src/editor.rs

@@ -1,34 +1,44 @@
-use std::process::Command;
+use std::{env, iter::once, process::Command};
 
-/// Editors the user might be using
+/// User default editor.
+///
+/// The user default editor is searched for in the environment variables
+/// `EDITOR` and `VISUAL`.
+///
+/// Any arguments to the program are extracted and stored separately so they can
+/// be passed to the program along with the path to open.
 #[derive(Debug, PartialEq)]
-pub enum Editor {
-    VSCode,
-    Zed,
+pub struct Editor {
+    /// Default options and arguments to the program.
+    args: Vec<String>,
+    /// The program to launch.
+    program: String,
 }
 
 impl Editor {
+    /// Search the environment variables `EDITOR` and `VISUAL` for the user
+    /// preferred editor.
     pub fn find() -> Option<Self> {
-        if Command::new("code").arg("--version").output().is_ok() {
-            return Some(Editor::VSCode);
-        }
-
-        if Command::new("zed").arg("--version").output().is_ok() {
-            return Some(Editor::Zed);
-        }
-
-        None
+        env::var("EDITOR")
+            .or_else(|_| env::var("VISUAL"))
+            .ok()
+            .filter(|value| !value.is_empty())
+            .map(|value| {
+                let mut parts = value.split_whitespace().map(String::from);
+                Self {
+                    program: parts.next().expect("there should be a program"),
+                    args: parts.collect(),
+                }
+            })
     }
 
+    /// Open the user default editor.
     pub fn open(&self, path: &str) {
-        Command::new(self.command()).arg(path).spawn().unwrap();
-    }
-
-    fn command(&self) -> &str {
-        match self {
-            Editor::VSCode => "code",
-            Editor::Zed => "zed",
-        }
+        let args = self.args.iter().map(|s| s.as_str()).chain(once(path));
+        Command::new(&self.program)
+            .args(args)
+            .spawn()
+            .expect("default editor failed to start");
     }
 }
 
@@ -37,7 +47,29 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_find_editor() {
+    fn test_find_user_editor() {
+        env::set_var("EDITOR", "editor --editor-flag");
+        env::set_var("VISUAL", "visual");
+        let editor = Editor::find();
+        let expected = Some(Editor {
+            args: vec![String::from("--editor-flag")],
+            program: String::from("editor"),
+        });
+        assert_eq!(editor, expected, "$EDITOR should be preferred editor");
+
+        env::remove_var("EDITOR");
+        env::set_var("VISUAL", "visual");
+        let editor = Editor::find();
+        let expected = Some(Editor {
+            args: vec![],
+            program: String::from("visual"),
+        });
+        assert_eq!(
+            editor, expected,
+            "$VISUAL should be used when $EDITOR is absent"
+        );
+
+        env::remove_var("VISUAL");
         let editor = Editor::find();
         assert_eq!(editor, None);
     }