cli: add nushell completion support

CHANGELOG.md

@@ -21,6 +21,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### New features
 
+* `jj util completion` now supports nushell completion generation with `--nushell`.
+
 ### Fixed bugs
 
 * Updating the working copy to a commit where a file that's currently ignored

Cargo.toml

@@ -27,6 +27,7 @@ bytes = "1.5.0"
 cargo_metadata = "0.17.0"
 clap = { version = "4.4.6", features = ["derive", "deprecated", "wrap_help"] }
 clap_complete = "4.4.3"
+clap_complete_nushell = "4.4.1"
 clap_mangen = "0.2.10"
 chrono = { version = "0.4.31", default-features = false, features = [
     "std",

cli/Cargo.toml

@@ -33,6 +33,7 @@ cargo_metadata = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true }
 clap_complete = { workspace = true }
+clap_complete_nushell = { workspace = true }
 clap_mangen = { workspace = true }
 config = { workspace = true }
 criterion = { workspace = true, optional = true }

cli/src/commands/mod.rs

@@ -1144,6 +1144,15 @@ struct UtilCompletionArgs {
     /// source <(jj util completion --zsh)
     #[arg(long, verbatim_doc_comment)]
     zsh: bool,
+    /// Print a completion script for Nushell
+    ///
+    /// Apply it by running this:
+    ///
+    /// jj util completion --nushell | save ~/.config/nushell/jj.nu
+    /// 'use ~/.config/nushell/jj.nu' | save --append $nu.config-path
+    /// source $nu.config-path
+    #[arg(long, verbatim_doc_comment)]
+    nushell: bool,
 }
 
 /// Print a ROFF (manpage)
@@ -3653,16 +3662,19 @@ fn cmd_util(
 ) -> Result<(), CommandError> {
     match subcommand {
         UtilCommands::Completion(completion_matches) => {
+            use clap_complete::{generate, Shell};
+
             let mut app = command.app().clone();
             let mut buf = vec![];
-            let shell = if completion_matches.zsh {
-                clap_complete::Shell::Zsh
+            if completion_matches.zsh {
+                generate(Shell::Zsh, &mut app, "jj", &mut buf);
             } else if completion_matches.fish {
-                clap_complete::Shell::Fish
+                generate(Shell::Fish, &mut app, "jj", &mut buf);
+            } else if completion_matches.nushell {
+                generate(clap_complete_nushell::Nushell, &mut app, "jj", &mut buf);
             } else {
-                clap_complete::Shell::Bash
+                generate(Shell::Bash, &mut app, "jj", &mut buf);
             };
-            clap_complete::generate(shell, &mut app, "jj", &mut buf);
             ui.stdout_formatter().write_all(&buf)?;
         }
         UtilCommands::Mangen(_mangen_matches) => {

docs/install-and-setup.md

@@ -142,7 +142,7 @@ $ jj config set --user user.email "[email protected]"
 ## Command-line completion
 
 To set up command-line completion, source the output of
-`jj util completion --bash/--zsh/--fish`. Exactly how to source it
+`jj util completion --bash/--zsh/--fish/--nushell`. Exactly how to source it
 depends on your shell.
 
 ### Bash
@@ -170,3 +170,11 @@ jj util completion --fish | source
 ```shell
 source-bash $(jj util completion)
 ```
+
+### Nushell
+
+```shell
+jj util completion --nushell | save ~/.config/nushell/jj.nu
+'use ~/.config/nushell/jj.nu' | save --append $nu.config-path
+source $nu.config-path
+```