Merge branch 'rsvg-convert-tab-completion' into 'main'

(#878): Add tab-completion for rsvg-convert

Closes #878

See merge request GNOME/librsvg!771

3 files changed, 43 insertions, 8 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 65ce70fe..716806d0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -180,9 +180,9 @@ checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
 
 [[package]]
 name = "cc"
-version = "1.0.76"
+version = "1.0.77"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76a284da2e6fe2092f2353e51713435363112dfd60030e22add80be333fb928f"
+checksum = "e9f73505338f7d905b19d18738976aae232eb46b8efc15554ffc56deb5d9ebe4"
 
 [[package]]
 name = "cfg-expr"
@@ -241,6 +241,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "clap_complete"
+version = "4.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96b0fba905b035a30d25c1b585bf1171690712fbb0ad3ac47214963aa4acc36c"
+dependencies = [
+ "clap 4.0.26",
+]
+
+[[package]]
 name = "clap_derive"
 version = "4.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -995,6 +1004,7 @@ dependencies = [
  "cast",
  "chrono",
  "clap 4.0.26",
+ "clap_complete",
  "criterion",
  "cssparser",
  "data-url",
@@ -1315,9 +1325,9 @@ checksum = "0ab1bc2a289d34bd04a330323ac98a1b4bc82c9d9fcb1e66b63caa84da26b575"
 
 [[package]]
 name = "os_str_bytes"
-version = "6.4.0"
+version = "6.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b5bf27447411e9ee3ff51186bf7a08e16c341efdde93f4d823e8844429bed7e"
+checksum = "9b7820b9daea5457c9f21c69448905d723fbd21136ccf521748f23fd49e723ee"
 
 [[package]]
 name = "pango"
diff --git a/Cargo.toml b/Cargo.toml
index a9aab9b6..9f209cb3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,6 +56,7 @@ cairo-rs = { version = "0.16", features=["v1_16", "png", "pdf", "ps", "svg"] }
 cast = "0.3.0"
 chrono = "0.4.0" # rsvg-convert
 clap = { version = "4.0.17", features = ["cargo", "derive"] } # rsvg-convert
+clap_complete = "4.0.5" # rsvg-convert
 cssparser = "0.28.0"
 data-url = "0.1"
 encoding = "0.2.33"
diff --git a/src/bin/rsvg-convert.rs b/src/bin/rsvg-convert.rs
index 586d8663..4895c2d4 100644
--- a/src/bin/rsvg-convert.rs
+++ b/src/bin/rsvg-convert.rs
@@ -1,4 +1,5 @@
 use clap::crate_version;
+use clap_complete::{Generator, Shell};
 
 use gio::prelude::*;
 use gio::{Cancellable, FileCreateFlags, InputStream, OutputStream};
@@ -27,6 +28,7 @@ use librsvg::rsvg_convert_only::{
 use librsvg::{AcceptLanguage, CairoRenderer, Color, Language, LengthUnit, Loader, RenderingError};
 
 use std::ffi::OsString;
+use std::io;
 use std::ops::Deref;
 use std::path::PathBuf;
 
@@ -770,7 +772,7 @@ fn natural_geometry(
     })
 }
 
-fn parse_args() -> Result<Converter, Error> {
+fn build_cli() -> clap::Command {
     let supported_formats = vec![
         "png",
         #[cfg(system_deps_have_cairo_pdf)]
@@ -783,7 +785,7 @@ fn parse_args() -> Result<Converter, Error> {
         "svg",
     ];
 
-    let app = clap::Command::new("rsvg-convert")
+    clap::Command::new("rsvg-convert")
         .version(concat!("version ", crate_version!()))
         .about("Convert SVG files to other image formats")
         .disable_version_flag(true)
@@ -1007,14 +1009,36 @@ fn parse_args() -> Result<Converter, Error> {
                 .action(clap::ArgAction::SetTrue),
         )
         .arg(
+            clap::Arg::new("completion")
+                .long("completion")
+                .help("Output shell completion for the given shell")
+                .num_args(1)
+                .action(clap::ArgAction::Set)
+                .value_parser(clap::value_parser!(Shell)),
+        )
+        .arg(
             clap::Arg::new("FILE")
                 .value_parser(clap::value_parser!(OsString))
                 .help("The input file(s) to convert")
                 .num_args(1..)
                 .action(clap::ArgAction::Append),
-        );
+        )
+}
+
+fn print_completions<G: Generator>(gen: G, cmd: &mut clap::Command) {
+    clap_complete::generate(gen, cmd, cmd.get_name().to_string(), &mut io::stdout());
+}
 
-    let matches = app.get_matches();
+fn parse_args() -> Result<Converter, Error> {
+    let cli = build_cli();
+    let matches = cli.get_matches();
+
+    if let Some(shell) = matches.get_one::<Shell>("completion").copied() {
+        let mut cmd = build_cli();
+        eprintln!("Generating completion file for {}", shell);
+        print_completions(shell, &mut cmd);
+        std::process::exit(0);
+    }
 
     let format_str: &String = matches
         .get_one("format")