Impl generate-completion subcommand

6 files changed, 34 insertions, 1 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1f0374ee..6b47c5d1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -303,6 +303,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "clap_complete"
+version = "4.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bffe91f06a11b4b9420f62103854e90867812cd5d01557f853c5ee8e791b12ae"
+dependencies = [
+ "clap",
+]
+
+[[package]]
 name = "clap_derive"
 version = "4.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -559,6 +568,7 @@ dependencies = [
  "chrono",
  "chrono-humanize",
  "clap",
+ "clap_complete",
  "console",
  "ctrlc",
  "dirs",
diff --git a/Cargo.toml b/Cargo.toml
index b54ed5d1..5aa04339 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -43,6 +43,7 @@ unicode-segmentation = "1.10.1"
 unicode-width = "0.1.10"
 vte = "0.11.0"
 xdg = "2.4.1"
+clap_complete = "4.4.4"
 
 [dependencies.git2]
 version = "0.17.2"
diff --git a/src/cli.rs b/src/cli.rs
index 817ab056..58d8ebef 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -4,6 +4,7 @@ use std::path::{Path, PathBuf};
 
 use bat::assets::HighlightingAssets;
 use clap::{ColorChoice, CommandFactory, FromArgMatches, Parser};
+use clap_complete::Shell;
 use lazy_static::lazy_static;
 use syntect::highlighting::Theme as SyntaxTheme;
 use syntect::parsing::SyntaxSet;
@@ -390,6 +391,10 @@ pub struct Opt {
     /// Sed-style command transforming file paths for display.
     pub file_regex_replacement: Option<String>,
 
+    #[arg(long = "generate-completion")]
+    /// Print completion file for the given shell.
+    pub generate_completion: Option<Shell>,
+
     #[arg(long = "grep-context-line-style", value_name = "STYLE")]
     /// Style string for non-matching lines of grep output.
     ///
@@ -1194,6 +1199,7 @@ impl Opt {
 // pseudo-flag commands such as --list-languages
 lazy_static! {
     static ref IGNORED_OPTION_NAMES: HashSet<&'static str> = vec![
+        "generate-completion",
         "list-languages",
         "list-syntax-themes",
         "show-config",
diff --git a/src/main.rs b/src/main.rs
index a1f12622..67ea0ca3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -82,7 +82,11 @@ fn run_app() -> std::io::Result<i32> {
         assets,
     );
 
-    let subcommand_result = if opt.list_languages {
+    let subcommand_result = if let Some(shell) = opt.generate_completion {
+        Some(subcommands::generate_completion::generate_completion_file(
+            shell,
+        ))
+    } else if opt.list_languages {
         Some(list_languages())
     } else if opt.list_syntax_themes {
         Some(subcommands::list_syntax_themes::list_syntax_themes())
diff --git a/src/subcommands/generate_completion.rs b/src/subcommands/generate_completion.rs
new file mode 100644
index 00000000..00425b7f
--- /dev/null
+++ b/src/subcommands/generate_completion.rs
@@ -0,0 +1,11 @@
+use clap::CommandFactory;
+use clap_complete::{generate, Shell};
+
+use crate::cli;
+
+pub fn generate_completion_file(shell: Shell) -> std::io::Result<()> {
+    let mut cmd = cli::Opt::command();
+    let bin_name = cmd.get_bin_name().unwrap_or(cmd.get_name()).to_string();
+    generate(shell, &mut cmd, bin_name, &mut std::io::stdout());
+    Ok(())
+}
diff --git a/src/subcommands/mod.rs b/src/subcommands/mod.rs
index 26f04233..bb7a1f7c 100644
--- a/src/subcommands/mod.rs
+++ b/src/subcommands/mod.rs
@@ -1,4 +1,5 @@
 pub mod diff;
+pub mod generate_completion;
 pub mod list_syntax_themes;
 pub mod parse_ansi;
 mod sample_diff;