fix: Update app_from_crate for App rename

Instead of just renaming it, I reconsidered what the API should look
like.  A custom separator for author does not make sense positionally
but accepting a name, and defaulting it, does fit with what someone
would expect.

I removed the `_from_crate` suffix because it doesn't seem necessary.
We don't have this kind of naming for the derive.  I feel it cleans
things up this way.

src/macros.rs

@@ -283,15 +283,10 @@ macro_rules! crate_name {
 
 /// Allows you to build the `Command` instance from your Cargo.toml at compile time.
 ///
-/// Equivalent to using the `crate_*!` macros with their respective fields.
-///
-/// Provided separator is for the [`crate_authors!`] macro,
-/// refer to the documentation therefor.
-///
 /// **NOTE:** Changing the values in your `Cargo.toml` does not trigger a re-build automatically,
 /// and therefore won't change the generated output until you recompile.
 ///
-/// **Pro Tip:** In some cases you can "trick" the compiler into triggering a rebuild when your
+/// In some cases you can "trick" the compiler into triggering a rebuild when your
 /// `Cargo.toml` is changed by including this in your `src/main.rs` file
 /// `include_str!("../Cargo.toml");`
 ///
@@ -301,11 +296,35 @@ macro_rules! crate_name {
 /// # #[macro_use]
 /// # extern crate clap;
 /// # fn main() {
-/// let m = app_from_crate!().get_matches();
+/// let m = command!().get_matches();
 /// # }
 /// ```
 #[cfg(feature = "cargo")]
 #[macro_export]
+macro_rules! command {
+    () => {{
+        $crate::command!($crate::crate_name!())
+    }};
+    ($name:expr) => {{
+        let mut cmd = $crate::Command::new($name).version($crate::crate_version!());
+
+        let author = $crate::crate_authors!();
+        if !author.is_empty() {
+            cmd = cmd.author(author)
+        }
+
+        let about = $crate::crate_description!();
+        if !about.is_empty() {
+            cmd = cmd.about(about)
+        }
+
+        cmd
+    }};
+}
+
+/// Deprecated, replaced with [`clap::command!`][crate::command]
+#[cfg(feature = "cargo")]
+#[macro_export]
 macro_rules! app_from_crate {
     () => {{
         let mut cmd = $crate::Command::new($crate::crate_name!()).version($crate::crate_version!());

tests/builder/command.rs

@@ -0,0 +1,27 @@
+#![cfg(feature = "cargo")]
+
+use clap::{command, error::ErrorKind};
+
+static EVERYTHING: &str = "clap {{version}}
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    clap
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+";
+
+#[test]
+fn command() {
+    let res = command!().try_get_matches_from(vec!["clap", "--help"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind(), ErrorKind::DisplayHelp);
+    assert_eq!(
+        err.to_string(),
+        EVERYTHING.replace("{{version}}", env!("CARGO_PKG_VERSION"))
+    );
+}

tests/builder/main.rs

@@ -6,6 +6,7 @@ mod arg_matcher_assertions;
 mod arg_settings;
 mod borrowed;
 mod cargo;
+mod command;
 mod conflicts;
 mod default_missing_vals;
 mod default_vals;