Add completions subcommand (#6568)

crates/typst-cli/Cargo.toml

@@ -29,6 +29,7 @@ typst-svg = { workspace = true }
 typst-timing = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true }
+clap_complete = { workspace = true }
 codespan-reporting = { workspace = true }
 color-print = { workspace = true }
 comemo = { workspace = true }

crates/typst-cli/src/args.rs

@@ -7,6 +7,7 @@ use std::str::FromStr;
 use chrono::{DateTime, Utc};
 use clap::builder::{TypedValueParser, ValueParser};
 use clap::{ArgAction, Args, ColorChoice, Parser, Subcommand, ValueEnum, ValueHint};
+use clap_complete::Shell;
 use semver::Version;
 
 /// The character typically used to separate path components
@@ -81,6 +82,9 @@ pub enum Command {
     /// Self update the Typst CLI.
     #[cfg_attr(not(feature = "self-update"), clap(hide = true))]
     Update(UpdateCommand),
+
+    /// Generates shell completion scripts.
+    Completions(CompletionsCommand),
 }
 
 /// Compiles an input file into a supported output format.
@@ -198,6 +202,14 @@ pub struct UpdateCommand {
     pub backup_path: Option<PathBuf>,
 }
 
+/// Generates shell completion scripts.
+#[derive(Debug, Clone, Parser)]
+pub struct CompletionsCommand {
+    /// The shell to generate completions for.
+    #[arg(value_enum)]
+    pub shell: Shell,
+}
+
 /// Arguments for compilation and watching.
 #[derive(Debug, Clone, Args)]
 pub struct CompileArgs {

crates/typst-cli/src/completions.rs

@@ -0,0 +1,13 @@
+use std::io::stdout;
+
+use clap::CommandFactory;
+use clap_complete::generate;
+
+use crate::args::{CliArguments, CompletionsCommand};
+
+/// Execute the completions command.
+pub fn completions(command: &CompletionsCommand) {
+    let mut cmd = CliArguments::command();
+    let bin_name = cmd.get_name().to_string();
+    generate(command.shell, &mut cmd, bin_name, &mut stdout());
+}

crates/typst-cli/src/main.rs

@@ -1,5 +1,6 @@
 mod args;
 mod compile;
+mod completions;
 mod download;
 mod fonts;
 mod greet;
@@ -71,6 +72,7 @@ fn dispatch() -> HintedStrResult<()> {
         Command::Query(command) => crate::query::query(command)?,
         Command::Fonts(command) => crate::fonts::fonts(command),
         Command::Update(command) => crate::update::update(command)?,
+        Command::Completions(command) => crate::completions::completions(command),
     }
 
     Ok(())