Add --completion option

Makefile

@@ -12,7 +12,10 @@ export LONG_VERSION
 all: test
 
 test:
-	cargo test
+	cargo test -- --test-threads=1
+
+watch:
+	cargo watch "test -- --test-threads=1"
 
 clean:
 	cargo clean

README.md

@@ -36,7 +36,7 @@ The tested version is below.
 ## Usage
 
 ```
-ptags 0.1.6-pre
+ptags 0.1.9-pre
 [email protected]
 A parallel universal-ctags wrapper for git repository
 
@@ -58,11 +58,13 @@ FLAGS:
 OPTIONS:
         --bin-ctags <bin_ctags>           Path to ctags binary [default: ctags]
         --bin-git <bin_git>               Path to git binary [default: git]
+        --completion <completion>         Generate shell completion file [possible values: bash, fish,
+                                          zsh, powershell]
     -e, --exclude <exclude>...            Glob pattern of exclude file ( ex. --exclude '*.rs' )
     -c, --opt-ctags <opt_ctags>...        Options passed to ctags
     -g, --opt-git <opt_git>...            Options passed to git
         --opt-git-lfs <opt_git_lfs>...    Options passed to git-lfs
-    -f, --file <output>                   Output filename [default: tags]
+    -f, --file <output>                   Output filename ( filename '-' means output to stdout ) [default: tags]
     -t, --thread <thread>                 Number of threads [default: 8]
 
 ARGS:

appveyor.yml

@@ -26,4 +26,4 @@ build: false
 test_script:
   - git submodule init
   - git submodule update
-  - cargo test
+  - cargo test -- -test-threads=1

src/bin.rs

@@ -85,6 +85,11 @@ pub struct Opt {
     /// Glob pattern of exclude file ( ex. --exclude '*.rs' )
     #[structopt(short = "e", long = "exclude", raw(number_of_values = "1"))]
     pub exclude: Vec<String>,
+
+    /// Generate shell completion file
+    #[structopt(long = "completion",
+                raw(possible_values = "&[\"bash\", \"fish\", \"zsh\", \"powershell\"]"))]
+    pub completion: Option<String>,
 }
 
 // ---------------------------------------------------------------------------------------------------------------------
@@ -185,6 +190,21 @@ fn write_tags(opt: &Opt, outputs: &[Output]) -> Result<()> {
 // ---------------------------------------------------------------------------------------------------------------------
 
 pub fn run_opt(opt: &Opt) -> Result<()> {
+    match opt.completion {
+        Some(ref x) => {
+            let shell = match x.as_str() {
+                "bash" => clap::Shell::Bash,
+                "fish" => clap::Shell::Fish,
+                "zsh" => clap::Shell::Zsh,
+                "powershell" => clap::Shell::PowerShell,
+                _ => clap::Shell::Bash,
+            };
+            Opt::clap().gen_completions("ptags", shell, "./");
+            return Ok(());
+        }
+        None => {}
+    }
+
     let files;
     let time_git_files = watch_time!({
         files = git_files(&opt)?;
@@ -230,6 +250,7 @@ pub fn run() -> Result<()> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::path::Path;
 
     #[test]
     fn test_run() {
@@ -257,4 +278,33 @@ mod tests {
             "Err(Error(Git(CommandFailed(\"aaa\", Error { repr: Os { code: 2, message: "
         );
     }
+
+    #[test]
+    fn test_run_completion() {
+        let args = vec!["ptags", "--completion", "bash"];
+        let opt = Opt::from_iter(args.iter());
+        let ret = run_opt(&opt);
+        assert!(ret.is_ok());
+        let args = vec!["ptags", "--completion", "fish"];
+        let opt = Opt::from_iter(args.iter());
+        let ret = run_opt(&opt);
+        assert!(ret.is_ok());
+        let args = vec!["ptags", "--completion", "zsh"];
+        let opt = Opt::from_iter(args.iter());
+        let ret = run_opt(&opt);
+        assert!(ret.is_ok());
+        let args = vec!["ptags", "--completion", "powershell"];
+        let opt = Opt::from_iter(args.iter());
+        let ret = run_opt(&opt);
+        assert!(ret.is_ok());
+
+        assert!(Path::new("ptags.bash").exists());
+        assert!(Path::new("ptags.fish").exists());
+        assert!(Path::new("_ptags").exists());
+        assert!(Path::new("_ptags.ps1").exists());
+        let _ = fs::remove_file("ptags.bash");
+        let _ = fs::remove_file("ptags.fish");
+        let _ = fs::remove_file("_ptags");
+        let _ = fs::remove_file("_ptags.ps1");
+    }
 }