Change Config To Flag (#290)

This changes the `config` subcommand to a config flag.

Add option subcommand for now, for the clearing of default path.

Add `ZELLIJ_CONFIG` environment variable.

The configuration locations are now as follows:
    * `--config` flag
    * `ZELLIJ_CONFIG` environment variable
    * default config location
in that order.

3 files changed, 22 insertions, 14 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 43047dd3..008fb28c 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,6 +1,9 @@
 use std::path::PathBuf;
 use structopt::StructOpt;
 
+// TODO add to consts.rs
+const ZELLIJ_CONFIG_ENV: &str = "ZELLIJ_CONFIG";
+
 #[derive(StructOpt, Default, Debug)]
 #[structopt(name = "zellij")]
 pub struct CliArgs {
@@ -28,8 +31,12 @@ pub struct CliArgs {
     #[structopt(short, long)]
     pub layout: Option<PathBuf>,
 
+    /// Change where zellij looks for the configuration
+    #[structopt(short, long, env=ZELLIJ_CONFIG_ENV)]
+    pub config: Option<PathBuf>,
+
     #[structopt(subcommand)]
-    pub config: Option<ConfigCli>,
+    pub option: Option<ConfigCli>,
 
     #[structopt(short, long)]
     pub debug: bool,
@@ -37,10 +44,9 @@ pub struct CliArgs {
 
 #[derive(Debug, StructOpt)]
 pub enum ConfigCli {
-    /// Path to the configuration yaml file
-    #[structopt(alias = "c")]
+    /// Change the behaviour of zellij
+    #[structopt(name = "option")]
     Config {
-        path: Option<PathBuf>,
         #[structopt(long)]
         /// Disables loading of configuration file at default location
         clean: bool,
diff --git a/src/common/input/config.rs b/src/common/input/config.rs
index 1926b11c..17e1edf1 100644
--- a/src/common/input/config.rs
+++ b/src/common/input/config.rs
@@ -79,19 +79,23 @@ impl Config {
 
     /// Entry point of the configuration
     #[cfg(not(test))]
-    pub fn from_cli_config(cli_config: Option<ConfigCli>) -> ConfigResult {
+    pub fn from_cli_config(
+        location: Option<PathBuf>,
+        cli_config: Option<ConfigCli>,
+    ) -> ConfigResult {
+        if let Some(path) = location {
+            return Config::new(&path);
+        }
+
         match cli_config {
             Some(ConfigCli::Config { clean, .. }) if clean => Ok(Config::default()),
-            Some(ConfigCli::Config { path, .. }) if path.is_some() => {
-                Ok(Config::new(&path.unwrap())?)
-            }
             Some(_) | None => Ok(Config::from_default_path()?),
         }
     }
 
     /// In order not to mess up tests from changing configurations
     #[cfg(test)]
-    pub fn from_cli_config(_: Option<ConfigCli>) -> ConfigResult {
+    pub fn from_cli_config(_: Option<PathBuf>, _: Option<ConfigCli>) -> ConfigResult {
         Ok(Config::default())
     }
 }
@@ -137,19 +141,17 @@ mod config_test {
 
     #[test]
     fn clean_option_equals_default_config() {
-        let no_file = PathBuf::from(r"../fixtures/config/config.yamlll");
         let cli_config = ConfigCli::Config {
-            path: Some(no_file),
             clean: true,
         };
-        let config = Config::from_cli_config(Some(cli_config)).unwrap();
+        let config = Config::from_cli_config(None, Some(cli_config)).unwrap();
         let default = Config::default();
         assert_eq!(config, default);
     }
 
     #[test]
     fn no_config_option_file_equals_default_config() {
-        let config = Config::from_cli_config(None).unwrap();
+        let config = Config::from_cli_config(None, None).unwrap();
         let default = Config::default();
         assert_eq!(config, default);
     }
diff --git a/src/common/mod.rs b/src/common/mod.rs
index 860d12db..e2cd2220 100644
--- a/src/common/mod.rs
+++ b/src/common/mod.rs
@@ -128,7 +128,7 @@ pub fn start(mut os_input: Box<dyn OsApi>, opts: CliArgs) {
         .write(take_snapshot.as_bytes())
         .unwrap();
 
-    let config = Config::from_cli_config(opts.config)
+    let config = Config::from_cli_config(opts.config, opts.option)
         .map_err(|e| {
             eprintln!("There was an error in the config file:\n{}", e);
             std::process::exit(1);