refactor: put every filesystem write behind one module

src/cli/ahab.rs

@@ -1,7 +1,7 @@
 use super::{Django, Link, Postgres};
 use clap::builder::styling::{AnsiColor, Effects, Styles};
-use clap::error::ErrorKind;
-use clap::{CommandFactory, Parser, Subcommand};
+
+use clap::{Parser, Subcommand};
 use clap_complete::Shell;
 
 /// A program for interacting with various dockerized applications
@@ -56,63 +56,13 @@ fn help_styles() -> Styles {
         .placeholder(AnsiColor::Cyan.on_default())
 }
 
-/// Exit with a usage error when `--dry-run` would be a lie
-pub fn reject_unsupported_dry_run(command: &Commands) {
-    if let Some(name) = writes_locally(command) {
-        Ahab::command()
-            .error(
-                ErrorKind::ArgumentConflict,
-                format!("--dry-run is not supported by `{name}`, which writes to the working tree"),
-            )
-            .exit()
-    }
-}
-
-// TODO:(@janezicmatej) honour --dry-run in these commands instead of refusing it
-fn writes_locally(command: &Commands) -> Option<&'static str> {
-    match command {
-        Commands::Link { command } => match command {
-            Link::Add { .. } => Some("link add"),
-            Link::Restore { .. } => Some("link restore"),
-            Link::Check { .. } => None,
-        },
-        Commands::Django { command } => match command {
-            Django::MakeCommand { .. } => Some("django make-command"),
-            _ => None,
-        },
-        Commands::Postgres { .. } | Commands::Completions { .. } => None,
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::Ahab;
-    use clap::{CommandFactory, Parser};
+    use clap::CommandFactory;
 
     #[test]
     fn the_command_is_well_formed() {
         Ahab::command().debug_assert();
     }
-
-    #[test]
-    fn dry_run_is_refused_only_where_it_cannot_be_honoured() {
-        let command = |args: &[&str]| Ahab::try_parse_from(args).unwrap().command;
-
-        assert_eq!(
-            super::writes_locally(&command(&["ahab", "link", "add", ".env"])),
-            Some("link add")
-        );
-        assert_eq!(
-            super::writes_locally(&command(&["ahab", "django", "make-command", "app", "name"])),
-            Some("django make-command")
-        );
-        assert_eq!(
-            super::writes_locally(&command(&["ahab", "link", "check"])),
-            None
-        );
-        assert_eq!(
-            super::writes_locally(&command(&["ahab", "postgres", "dump", "out.sql"])),
-            None
-        );
-    }
 }