fix: Update derive->Command function name

No good solution for transitioning the trate name, unfortnately, since
we can't mark `use`s as deprecated (we can, it just does nothing).

I got rid of the `into` prefix because that implies a `self` parameter
that doesn't exist.

clap_complete/examples/value_hints_derive.rs

@@ -65,7 +65,7 @@ fn main() {
     let opt = Opt::parse();
 
     if let Some(generator) = opt.generator {
-        let mut cmd = Opt::into_app();
+        let mut cmd = Opt::command();
         eprintln!("Generating completion file for {:?}...", generator);
         print_completions(generator, &mut cmd);
     } else {

clap_derive/src/derives/into_app.rs

@@ -56,6 +56,7 @@ pub fn gen_for_struct(
             clippy::suspicious_else_formatting,
         )]
         #[deny(clippy::correctness)]
+        #[allow(deprecated)]
         impl #impl_generics clap::IntoApp for #struct_name #ty_generics #where_clause {
             fn into_app<'b>() -> clap::Command<'b> {
                 let #app_var = clap::Command::new(#name);

clap_derive/src/dummies.rs

@@ -18,6 +18,7 @@ pub fn parser_enum(name: &Ident) {
 
 pub fn into_app(name: &Ident) {
     append_dummy(quote! {
+        #[allow(deprecated)]
         impl clap::IntoApp for #name {
             fn into_app<'b>() -> clap::Command<'b> {
                 unimplemented!()

examples/tutorial_derive/04_04_custom.rs

@@ -41,7 +41,7 @@ fn main() {
     // See if --set-ver was used to set the version manually
     let version = if let Some(ver) = cli.set_ver.as_deref() {
         if cli.major || cli.minor || cli.patch {
-            let mut cmd = Cli::into_app();
+            let mut cmd = Cli::command();
             cmd.error(
                 ErrorKind::ArgumentConflict,
                 "Can't do relative and absolute version change",
@@ -57,7 +57,7 @@ fn main() {
             (false, true, false) => minor += 1,
             (false, false, true) => patch += 1,
             _ => {
-                let mut cmd = Cli::into_app();
+                let mut cmd = Cli::command();
                 cmd.error(
                     ErrorKind::ArgumentConflict,
                     "Cam only modify one version field",
@@ -80,7 +80,7 @@ fn main() {
             // 'or' is preferred to 'or_else' here since `Option::as_deref` is 'const'
             .or(cli.spec_in.as_deref())
             .unwrap_or_else(|| {
-                let mut cmd = Cli::into_app();
+                let mut cmd = Cli::command();
                 cmd.error(
                     ErrorKind::MissingRequiredArgument,
                     "INPUT_FILE or --spec-in is required when using --config",

examples/tutorial_derive/05_01_assert.rs

@@ -17,5 +17,5 @@ fn main() {
 #[test]
 fn verify_app() {
     use clap::IntoApp;
-    Cli::into_app().debug_assert()
+    Cli::command().debug_assert()
 }

src/derive.rs

@@ -79,7 +79,7 @@ use std::ffi::OsString;
 pub trait Parser: FromArgMatches + IntoApp + Sized {
     /// Parse from `std::env::args_os()`, exit on error
     fn parse() -> Self {
-        let matches = <Self as IntoApp>::into_app().get_matches();
+        let matches = <Self as IntoApp>::command().get_matches();
         let res =
             <Self as FromArgMatches>::from_arg_matches(&matches).map_err(format_error::<Self>);
         match res {
@@ -94,7 +94,7 @@ pub trait Parser: FromArgMatches + IntoApp + Sized {
 
     /// Parse from `std::env::args_os()`, return Err on error.
     fn try_parse() -> Result<Self, Error> {
-        let matches = <Self as IntoApp>::into_app().try_get_matches()?;
+        let matches = <Self as IntoApp>::command().try_get_matches()?;
         <Self as FromArgMatches>::from_arg_matches(&matches).map_err(format_error::<Self>)
     }
 
@@ -104,7 +104,7 @@ pub trait Parser: FromArgMatches + IntoApp + Sized {
         I: IntoIterator<Item = T>,
         T: Into<OsString> + Clone,
     {
-        let matches = <Self as IntoApp>::into_app().get_matches_from(itr);
+        let matches = <Self as IntoApp>::command().get_matches_from(itr);
         let res =
             <Self as FromArgMatches>::from_arg_matches(&matches).map_err(format_error::<Self>);
         match res {
@@ -123,7 +123,7 @@ pub trait Parser: FromArgMatches + IntoApp + Sized {
         I: IntoIterator<Item = T>,
         T: Into<OsString> + Clone,
     {
-        let matches = <Self as IntoApp>::into_app().try_get_matches_from(itr)?;
+        let matches = <Self as IntoApp>::command().try_get_matches_from(itr)?;
         <Self as FromArgMatches>::from_arg_matches(&matches).map_err(format_error::<Self>)
     }
 
@@ -133,7 +133,7 @@ pub trait Parser: FromArgMatches + IntoApp + Sized {
         I: IntoIterator<Item = T>,
         T: Into<OsString> + Clone,
     {
-        let matches = <Self as IntoApp>::into_app_for_update().get_matches_from(itr);
+        let matches = <Self as IntoApp>::command().get_matches_from(itr);
         let res = <Self as FromArgMatches>::update_from_arg_matches(self, &matches)
             .map_err(format_error::<Self>);
         if let Err(e) = res {
@@ -149,20 +149,20 @@ pub trait Parser: FromArgMatches + IntoApp + Sized {
         I: IntoIterator<Item = T>,
         T: Into<OsString> + Clone,
     {
-        let matches = <Self as IntoApp>::into_app_for_update().try_get_matches_from(itr)?;
+        let matches = <Self as IntoApp>::command().try_get_matches_from(itr)?;
         <Self as FromArgMatches>::update_from_arg_matches(self, &matches)
             .map_err(format_error::<Self>)
     }
 
-    /// Deprecated, `StructOpt::clap` replaced with [`IntoCommand::into_app`] (derive as part of
+    /// Deprecated, `StructOpt::clap` replaced with [`IntoCommand::command`] (derive as part of
     /// [`Parser`])
     #[deprecated(
         since = "3.0.0",
-        note = "`StructOpt::clap` is replaced with `IntoCommand::into_app` (derived as part of `Parser`)"
+        note = "`StructOpt::clap` is replaced with `IntoCommand::command` (derived as part of `Parser`)"
     )]
     #[doc(hidden)]
     fn clap<'help>() -> Command<'help> {
-        <Self as IntoApp>::into_app()
+        <Self as IntoApp>::command()
     }
 
     /// Deprecated, `StructOpt::from_clap` replaced with [`FromArgMatches::from_arg_matches`] (derive as part of
@@ -233,10 +233,22 @@ pub trait IntoApp: Sized {
     /// Build an [`Command`] that can instantiate `Self`.
     ///
     /// See [`FromArgMatches::from_arg_matches`] for instantiating `Self`.
+    fn command<'help>() -> Command<'help> {
+        #[allow(deprecated)]
+        Self::into_app()
+    }
+    /// Deprecated, replaced with `IntoApp::command`
+    #[deprecated(since = "3.1.0", note = "Replaced with `IntoApp::command")]
     fn into_app<'help>() -> Command<'help>;
     /// Build an [`Command`] that can update `self`.
     ///
     /// See [`FromArgMatches::update_from_arg_matches`] for updating `self`.
+    fn command_for_update<'help>() -> Command<'help> {
+        #[allow(deprecated)]
+        Self::into_app_for_update()
+    }
+    /// Deprecated, replaced with `IntoApp::command_for_update`
+    #[deprecated(since = "3.1.0", note = "Replaced with `IntoApp::command_for_update")]
     fn into_app_for_update<'help>() -> Command<'help>;
 }
 
@@ -451,6 +463,7 @@ impl<T: Parser> Parser for Box<T> {
     }
 }
 
+#[allow(deprecated)]
 impl<T: IntoApp> IntoApp for Box<T> {
     fn into_app<'help>() -> Command<'help> {
         <T as IntoApp>::into_app()
@@ -491,6 +504,6 @@ impl<T: Subcommand> Subcommand for Box<T> {
 }
 
 fn format_error<I: IntoApp>(err: crate::Error) -> crate::Error {
-    let mut cmd = I::into_app();
+    let mut cmd = I::command();
     err.format(&mut cmd)
 }

tests/derive/app_name.rs

@@ -7,7 +7,7 @@ fn app_name_in_short_help_from_struct() {
     struct MyApp {}
 
     let mut help = Vec::new();
-    MyApp::into_app().write_help(&mut help).unwrap();
+    MyApp::command().write_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("my-cmd"));
@@ -20,7 +20,7 @@ fn app_name_in_long_help_from_struct() {
     struct MyApp {}
 
     let mut help = Vec::new();
-    MyApp::into_app().write_long_help(&mut help).unwrap();
+    MyApp::command().write_long_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("my-cmd"));
@@ -33,7 +33,7 @@ fn app_name_in_short_help_from_enum() {
     enum MyApp {}
 
     let mut help = Vec::new();
-    MyApp::into_app().write_help(&mut help).unwrap();
+    MyApp::command().write_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("my-cmd"));
@@ -46,7 +46,7 @@ fn app_name_in_long_help_from_enum() {
     enum MyApp {}
 
     let mut help = Vec::new();
-    MyApp::into_app().write_long_help(&mut help).unwrap();
+    MyApp::command().write_long_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("my-cmd"));
@@ -58,7 +58,7 @@ fn app_name_in_short_version_from_struct() {
     #[clap(name = "my-cmd")]
     struct MyApp {}
 
-    let version = MyApp::into_app().render_version();
+    let version = MyApp::command().render_version();
 
     assert!(version.contains("my-cmd"));
 }
@@ -69,7 +69,7 @@ fn app_name_in_long_version_from_struct() {
     #[clap(name = "my-cmd")]
     struct MyApp {}
 
-    let version = MyApp::into_app().render_long_version();
+    let version = MyApp::command().render_long_version();
 
     assert!(version.contains("my-cmd"));
 }
@@ -80,7 +80,7 @@ fn app_name_in_short_version_from_enum() {
     #[clap(name = "my-cmd")]
     enum MyApp {}
 
-    let version = MyApp::into_app().render_version();
+    let version = MyApp::command().render_version();
 
     assert!(version.contains("my-cmd"));
 }
@@ -91,7 +91,7 @@ fn app_name_in_long_version_from_enum() {
     #[clap(name = "my-cmd")]
     enum MyApp {}
 
-    let version = MyApp::into_app().render_long_version();
+    let version = MyApp::command().render_long_version();
 
     assert!(version.contains("my-cmd"));
 }

tests/derive/arguments.rs

@@ -52,7 +52,7 @@ fn auto_value_name() {
     }
 
     let mut help = Vec::new();
-    Opt::into_app().write_help(&mut help).unwrap();
+    Opt::command().write_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("MY_SPECIAL_ARG"));
@@ -72,7 +72,7 @@ fn explicit_value_name() {
     }
 
     let mut help = Vec::new();
-    Opt::into_app().write_help(&mut help).unwrap();
+    Opt::command().write_help(&mut help).unwrap();
     let help = String::from_utf8(help).unwrap();
 
     assert!(help.contains("BROWNIE_POINTS"));

tests/derive/default_value.rs

@@ -53,5 +53,5 @@ fn detect_os_variant() {
         #[clap(default_value_os = ("123".as_ref()))]
         x: String,
     }
-    Options::into_app().debug_assert();
+    Options::command().debug_assert();
 }

tests/derive/doc_comments_help.rs

@@ -232,7 +232,7 @@ fn doc_comment_about_handles_both_abouts() {
         Compress { output: String },
     }
 
-    let cmd = Opts::into_app();
+    let cmd = Opts::command();
     assert_eq!(cmd.get_about(), Some("Opts doc comment summary"));
     // clap will fallback to `about` on `None`.  The main care about is not providing a `Sub` doc
     // comment.

tests/derive/help.rs

@@ -12,7 +12,7 @@ fn arg_help_heading_applied() {
         no_section: u32,
     }
 
-    let cmd = CliOptions::into_app();
+    let cmd = CliOptions::command();
 
     let should_be_in_section_a = cmd
         .get_arguments()
@@ -40,7 +40,7 @@ fn app_help_heading_applied() {
         should_be_in_default_section: u32,
     }
 
-    let cmd = CliOptions::into_app();
+    let cmd = CliOptions::command();
 
     let should_be_in_section_a = cmd
         .get_arguments()
@@ -117,7 +117,7 @@ fn app_help_heading_flattened() {
         SubCOne { should_be_in_sub_c: u32 },
     }
 
-    let cmd = CliOptions::into_app();
+    let cmd = CliOptions::command();
 
     let should_be_in_section_a = cmd
         .get_arguments()
@@ -178,7 +178,7 @@ fn flatten_field_with_help_heading() {
         should_be_in_section_a: u32,
     }
 
-    let cmd = CliOptions::into_app();
+    let cmd = CliOptions::command();
 
     let should_be_in_section_a = cmd
         .get_arguments()
@@ -278,7 +278,7 @@ OPTIONS:
     }
 
     use clap::IntoApp;
-    let mut cmd = Args::into_app();
+    let mut cmd = Args::command();
 
     let mut buffer: Vec<u8> = Default::default();
     cmd.write_help(&mut buffer).unwrap();
@@ -335,7 +335,7 @@ OPTIONS:
     }
 
     use clap::IntoApp;
-    let mut cmd = Args::into_app();
+    let mut cmd = Args::command();
 
     let mut buffer: Vec<u8> = Default::default();
     cmd.write_help(&mut buffer).unwrap();
@@ -391,7 +391,7 @@ OPTIONS:
     }
 
     use clap::IntoApp;
-    let mut cmd = Args::into_app();
+    let mut cmd = Args::command();
 
     let mut buffer: Vec<u8> = Default::default();
     cmd.write_help(&mut buffer).unwrap();

tests/derive/utils.rs

@@ -9,7 +9,7 @@ use clap::IntoApp;
 
 pub fn get_help<T: IntoApp>() -> String {
     let mut output = Vec::new();
-    <T as IntoApp>::into_app().write_help(&mut output).unwrap();
+    <T as IntoApp>::command().write_help(&mut output).unwrap();
     let output = String::from_utf8(output).unwrap();
 
     eprintln!("\n%%% HELP %%%:=====\n{}\n=====\n", output);
@@ -20,7 +20,7 @@ pub fn get_help<T: IntoApp>() -> String {
 
 pub fn get_long_help<T: IntoApp>() -> String {
     let mut output = Vec::new();
-    <T as IntoApp>::into_app()
+    <T as IntoApp>::command()
         .write_long_help(&mut output)
         .unwrap();
     let output = String::from_utf8(output).unwrap();
@@ -33,7 +33,7 @@ pub fn get_long_help<T: IntoApp>() -> String {
 
 pub fn get_subcommand_long_help<T: IntoApp>(subcmd: &str) -> String {
     let mut output = Vec::new();
-    <T as IntoApp>::into_app()
+    <T as IntoApp>::command()
         .get_subcommands_mut()
         .find(|s| s.get_name() == subcmd)
         .unwrap()