feat(complete): Skeleton for Rust-driven completions

clap_complete/Cargo.toml

@@ -36,14 +36,27 @@ bench = false
 
 [dependencies]
 clap = { path = "../", version = "3.1.10", default-features = false, features = ["std"] }
+clap_lex = { path = "../clap_lex", version = "0.1.0", optional = true }
+is_executable = { version = "1.0.1", optional = true }
+os_str_bytes = { version = "6.0", default-features = false, features = ["raw_os_str"], optional = true }
+pathdiff = { version = "0.2.1", optional = true }
+shlex = { version = "1.1.0", optional = true }
+unicode-xid = { version = "0.2.2", optional = true }
 
 [dev-dependencies]
 pretty_assertions = "1.0"
 snapbox = { version = "0.2", features = ["diff"] }
+# Cutting out `filesystem` feature
+trycmd = { version = "0.13", default-features = false, features = ["color-auto", "diff", "examples"] }
 clap = { path = "../", version = "3.1.10", default-features = false, features = ["std", "derive"] }
 
+[[example]]
+name = "dynamic"
+required-features = ["unstable-dynamic"]
+
 [features]
 default = []
+unstable-dynamic = ["clap_lex", "shlex", "unicode-xid", "os_str_bytes", "clap/derive", "is_executable", "pathdiff"]
 debug = ["clap/debug"]
 
 [package.metadata.docs.rs]

clap_complete/examples/dynamic.rs

@@ -0,0 +1,39 @@
+use clap::FromArgMatches;
+use clap::Subcommand;
+
+fn command() -> clap::Command<'static> {
+    let cmd = clap::Command::new("dynamic")
+        .arg(
+            clap::Arg::new("input")
+                .long("--input")
+                .short('i')
+                .value_hint(clap::ValueHint::FilePath),
+        )
+        .arg(
+            clap::Arg::new("format")
+                .long("--format")
+                .short('F')
+                .possible_values(["json", "yaml", "toml"]),
+        )
+        .args_conflicts_with_subcommands(true);
+    let cmd = clap_complete::dynamic::bash::CompleteCommand::augment_subcommands(cmd);
+    cmd
+}
+
+fn main() {
+    let cmd = command();
+    let matches = cmd.get_matches();
+    if let Ok(completions) =
+        clap_complete::dynamic::bash::CompleteCommand::from_arg_matches(&matches)
+    {
+        completions.complete(&mut command());
+    } else {
+        println!("{:#?}", matches);
+    }
+}
+
+#[test]
+fn verify_cli() {
+    use clap::CommandFactory;
+    command().command().debug_assert();
+}