fix(help)!: Merge OPTIONS / FLAGS default groups

For those that want the original behavior, you can usxe
`arg.help_heading(Some("FLAGS"))` on your flags.  Limitations:
- This will not give you a special sort order
- This will not get a `[FLAGS]` added to usage

For templates, we removed `{unified}` and `{flags}`.  To help people
catch these, a debug_assert was added.

I'm unsure but I think there might be a change in behavior in calcuating
when to show `[OPTION]` in usage.  The old code only looked at
`required` while flags looked only at arg groups.  We now look at both.

Ideally we'd add these in `_build` and remove special casing for
no-groups except in the sort order of groups.  I feel like thats best
left for later.

This also reduced the scope of `App`s public API.
`get_*_with_no_heading` seemed a bit specialized to be in the public
API.  clap-rs#2853 looks at splitting it out into its own PR.

BREAKING CHANGE: Multiple
- `UnifiedHelpMessage` removed
- `{flags}` and `{unified}` are removed and will assert when present.
- `get_*_with_no_heading` removed

Fixes clap-rs#2807

README.md

@@ -385,15 +385,13 @@ ARGS:
     INPUT    The input file to use
 
 USAGE:
-    MyApp [FLAGS] [OPTIONS] <INPUT> [SUBCOMMAND]
-
-FLAGS:
-    -h, --help       Print help information
-    -v               Sets the level of verbosity
-    -V, --version    Print version information
+    MyApp [OPTIONS] <INPUT> [SUBCOMMAND]
 
 OPTIONS:
     -c, --config <FILE>    Sets a custom config file
+    -h, --help             Print help information
+    -v                     Sets the level of verbosity
+    -V, --version          Print version information
 
 SUBCOMMANDS:
     help    Print this message or the help of the given subcommand(s)

benches/04_new_help.rs

@@ -196,7 +196,7 @@ pub fn example10(c: &mut Criterion) {
 }
 
 pub fn example4_template(c: &mut Criterion) {
-    let mut app = app_example4().help_template("{bin} {version}\n{author}\n{about}\n\nUSAGE:\n    {usage}\n\nFLAGS:\n{flags}\n\nARGS:\n{args}\n");
+    let mut app = app_example4().help_template("{bin} {version}\n{author}\n{about}\n\nUSAGE:\n    {usage}\n\nOPTIONS:\n{options}\n\nARGS:\n{args}\n");
     c.bench_function("example4_template", |b| b.iter(|| build_help(&mut app)));
 }
 

benches/05_ripgrep.rs

@@ -3,7 +3,7 @@
 //
 // CLI used is adapted from ripgrep 48a8a3a691220f9e5b2b08f4051abe8655ea7e8a
 
-use clap::{App, AppSettings, Arg, ArgSettings};
+use clap::{App, Arg, ArgSettings};
 use criterion::{criterion_group, criterion_main, Criterion};
 use std::collections::HashMap;
 use std::io::Cursor;
@@ -267,7 +267,7 @@ ARGS:
 {positionals}
 
 OPTIONS:
-{unified}";
+{options}";
 
 /// Build a clap application with short help strings.
 fn app_short() -> App<'static> {
@@ -306,7 +306,6 @@ where
         .version("0.4.0") // Simulating
         .about(ABOUT)
         .max_term_width(100)
-        .setting(AppSettings::UnifiedHelpMessage)
         .override_usage(USAGE)
         .help_template(TEMPLATE)
         // Handle help/version manually to make their output formatting

clap_derive/README.md

@@ -82,22 +82,20 @@ Guillaume Pinot <texitoi@texitoi.eu>, others
 A basic example
 
 USAGE:
-    basic [FLAGS] [OPTIONS] --output <output> [--] [file]...
+    basic [OPTIONS] --output <output> [--] [file]...
 
 ARGS:
     <FILE>...    Files to process
 
-FLAGS:
-    -d, --debug      Activate debug mode
-    -h, --help       Print help information
-    -V, --version    Print version information
-    -v, --verbose    Verbose mode (-v, -vv, -vvv, etc.)
-
 OPTIONS:
-    -l, --level <level>...     admin_level to consider
     -c, --nb-cars <nb-cars>    Number of cars
+    -d, --debug                Activate debug mode
+    -h, --help                 Print help information
+    -l, --level <level>...     admin_level to consider
     -o, --output <output>      Output file
     -s, --speed <speed>        Set speed [default: 42]
+    -V, --version              Print version information
+    -v, --verbose              Verbose mode (-v, -vv, -vvv, etc.)
 
 ARGS:
     <file>...    Files to process

clap_derive/tests/non_literal_attributes.rs

@@ -19,7 +19,7 @@ pub const DISPLAY_ORDER: usize = 2;
 
 // Check if the global settings compile
 #[derive(Parser, Debug, PartialEq, Eq)]
-#[clap(global_setting = AppSettings::UnifiedHelpMessage)]
+#[clap(global_setting = AppSettings::AllowLeadingHyphen)]
 struct Opt {
     #[clap(
         long = "x",

site/content/_index.md

@@ -50,11 +50,9 @@ Simple program to greet a person
 USAGE:
     hello [OPTIONS] --name <name>
 
-FLAGS:
-    -h, --help       Print help information
-    -V, --version    Print version information
-
 OPTIONS:
     -c, --count <count>    Number of times to greet [default: 1]
+    -h, --help             Print help information
     -n, --name <name>      Name of the person to greet
+    -V, --version          Print version information
 ```

src/build/app/debug_asserts.rs

@@ -283,6 +283,19 @@ pub(crate) fn assert_app(app: &App) {
     detect_duplicate_flags(&long_flags, "long");
     detect_duplicate_flags(&short_flags, "short");
 
+    if let Some(help_template) = app.template {
+        assert!(
+            !help_template.contains("{flags}"),
+            "{}",
+            "`{flags}` template variable was removed in clap3, they are now included in `{options}`"
+        );
+        assert!(
+            !help_template.contains("{unified}"),
+            "{}",
+            "`{unified}` template variable was removed in clap3, use `{options}` instead"
+        );
+    }
+
     app._panic_on_missing_help(app.g_settings.is_set(AppSettings::HelpRequired));
     assert_app_flags(app);
 }

src/build/app/mod.rs

@@ -205,7 +205,7 @@ impl<'help> App<'help> {
         self.args.args()
     }
 
-    /// Iterate through the *positionals*.
+    /// Iterate through the *positionals* arguments.
     #[inline]
     pub fn get_positionals(&self) -> impl Iterator<Item = &Arg<'help>> {
         self.get_arguments().filter(|a| a.is_positional())
@@ -223,22 +223,6 @@ impl<'help> App<'help> {
             .filter(|a| a.is_set(ArgSettings::TakesValue) && a.get_index().is_none())
     }
 
-    /// Iterate through the *positionals* that don't have custom heading.
-    pub fn get_positionals_with_no_heading(&self) -> impl Iterator<Item = &Arg<'help>> {
-        self.get_positionals()
-            .filter(|a| a.get_help_heading().is_none())
-    }
-
-    /// Iterate through the *flags* that don't have custom heading.
-    pub fn get_flags_with_no_heading(&self) -> impl Iterator<Item = &Arg<'help>> {
-        self.get_flags().filter(|a| a.get_help_heading().is_none())
-    }
-
-    /// Iterate through the *options* that don't have custom heading.
-    pub fn get_opts_with_no_heading(&self) -> impl Iterator<Item = &Arg<'help>> {
-        self.get_opts().filter(|a| a.get_help_heading().is_none())
-    }
-
     // Get a list of subcommands which contain the provided Argument
     //
     // This command will only include subcommands in its list for which the subcommands
@@ -862,10 +846,6 @@ impl<'help> App<'help> {
     ///   * `{usage}`               - Automatically generated or given usage string.
     ///   * `{all-args}`            - Help for all arguments (options, flags, positional
     ///                               arguments, and subcommands) including titles.
-    ///   * `{unified}`             - Unified help for options and flags. Note, you must *also*
-    ///                               set [`AppSettings::UnifiedHelpMessage`] to fully merge both
-    ///                               options and flags, otherwise the ordering is "best effort".
-    ///   * `{flags}`               - Help for flags.
     ///   * `{options}`             - Help for options.
     ///   * `{positionals}`         - Help for positional arguments.
     ///   * `{subcommands}`         - Help for subcommands.
@@ -1093,7 +1073,7 @@ impl<'help> App<'help> {
     /// header for the specified argument type) until a subsequent call to
     /// [`App::help_heading`] or [`App::stop_custom_headings`].
     ///
-    /// This is useful if the default `FLAGS`, `OPTIONS`, or `ARGS` headings are
+    /// This is useful if the default `OPTIONS` or `ARGS` headings are
     /// not specific enough for one's use case.
     ///
     /// [`App::arg`]: App::arg()
@@ -1709,9 +1689,9 @@ impl<'help> App<'help> {
     /// cust-ord
     ///
     /// USAGE:
-    ///     cust-ord [FLAGS] [OPTIONS]
+    ///     cust-ord [OPTIONS]
     ///
-    /// FLAGS:
+    /// OPTIONS:
     ///     -h, --help       Print help information
     ///     -V, --version    Print version information
     ///
@@ -2177,7 +2157,7 @@ impl<'help> App<'help> {
     /// USAGE:
     ///     myprog [SUBCOMMAND]
     ///
-    /// FLAGS:
+    /// OPTIONS:
     ///     -h, --help       Print help information
     ///     -V, --version    Print version information
     ///
@@ -2205,7 +2185,7 @@ impl<'help> App<'help> {
     /// USAGE:
     ///     myprog [THING]
     ///
-    /// FLAGS:
+    /// OPTIONS:
     ///     -h, --help       Print help information
     ///     -V, --version    Print version information
     ///
@@ -2651,6 +2631,23 @@ impl<'a, T> Captures<'a> for T {}
 
 // Internal Query Methods
 impl<'help> App<'help> {
+    /// Iterate through the *named* arguments.
+    pub(crate) fn get_non_positional(&self) -> impl Iterator<Item = &Arg<'help>> {
+        self.get_arguments().filter(|a| !a.is_positional())
+    }
+
+    /// Iterate through the *positionals* that don't have custom heading.
+    pub(crate) fn get_positionals_with_no_heading(&self) -> impl Iterator<Item = &Arg<'help>> {
+        self.get_positionals()
+            .filter(|a| a.get_help_heading().is_none())
+    }
+
+    /// Iterate through the *named* that don't have custom heading.
+    pub(crate) fn get_non_positional_with_no_heading(&self) -> impl Iterator<Item = &Arg<'help>> {
+        self.get_non_positional()
+            .filter(|a| a.get_help_heading().is_none())
+    }
+
     pub(crate) fn find(&self, arg_id: &Id) -> Option<&Arg<'help>> {
         self.args.args().find(|a| a.id == *arg_id)
     }

src/build/app/settings.rs

@@ -11,7 +11,6 @@ bitflags! {
         const ARG_REQUIRED_ELSE_HELP         = 1 << 2;
         const PROPAGATE_VERSION              = 1 << 3;
         const DISABLE_VERSION_FOR_SC         = 1 << 4;
-        const UNIFIED_HELP                   = 1 << 5;
         const WAIT_ON_ERROR                  = 1 << 6;
         const SC_REQUIRED_ELSE_HELP          = 1 << 7;
         const NO_AUTO_HELP                   = 1 << 8;
@@ -122,8 +121,6 @@ impl_settings! { AppSettings, AppFlags,
         => Flags::USE_LONG_FORMAT_FOR_HELP_SC,
     TrailingVarArg("trailingvararg")
         => Flags::TRAILING_VARARG,
-    UnifiedHelpMessage("unifiedhelpmessage")
-        => Flags::UNIFIED_HELP,
     NextLineHelp("nextlinehelp")
         => Flags::NEXT_LINE_HELP,
     IgnoreErrors("ignoreerrors")
@@ -958,25 +955,6 @@ pub enum AppSettings {
     /// [`Arg::multiple_values(true)`]: crate::Arg::multiple_values()
     TrailingVarArg,
 
-    /// Groups flags and options together, presenting a more unified help message
-    /// (a la `getopts` or `docopt` style).
-    ///
-    /// The default is that the auto-generated help message will group flags, and options
-    /// separately.
-    ///
-    /// **NOTE:** This setting is cosmetic only and does not affect any functionality.
-    ///
-    /// # Examples
-    ///
-    /// ```rust
-    /// # use clap::{App, Arg, AppSettings};
-    /// App::new("myprog")
-    ///     .setting(AppSettings::UnifiedHelpMessage)
-    ///     .get_matches();
-    /// // running `myprog --help` will display a unified "docopt" or "getopts" style help message
-    /// ```
-    UnifiedHelpMessage,
-
     /// Will display a message "Press \[ENTER\]/\[RETURN\] to continue..." and wait for user before
     /// exiting
     ///
@@ -1164,10 +1142,6 @@ mod test {
             "trailingvararg".parse::<AppSettings>().unwrap(),
             AppSettings::TrailingVarArg
         );
-        assert_eq!(
-            "unifiedhelpmessage".parse::<AppSettings>().unwrap(),
-            AppSettings::UnifiedHelpMessage
-        );
         assert_eq!(
             "waitonerror".parse::<AppSettings>().unwrap(),
             AppSettings::WaitOnError

src/build/app/tests.rs

@@ -13,21 +13,21 @@ fn propagate_version() {
 #[test]
 fn global_setting() {
     let mut app = App::new("test")
-        .global_setting(AppSettings::UnifiedHelpMessage)
+        .global_setting(AppSettings::AllowLeadingHyphen)
         .subcommand(App::new("subcmd"));
     app._propagate();
     assert!(app
         .subcommands
         .iter()
         .find(|s| s.name == "subcmd")
         .unwrap()
-        .is_set(AppSettings::UnifiedHelpMessage));
+        .is_set(AppSettings::AllowLeadingHyphen));
 }
 
 #[test]
 fn global_settings() {
     let mut app = App::new("test")
-        .global_setting(AppSettings::UnifiedHelpMessage)
+        .global_setting(AppSettings::AllowLeadingHyphen)
         .global_setting(AppSettings::TrailingVarArg)
         .subcommand(App::new("subcmd"));
     app._propagate();
@@ -36,7 +36,7 @@ fn global_settings() {
         .iter()
         .find(|s| s.name == "subcmd")
         .unwrap()
-        .is_set(AppSettings::UnifiedHelpMessage));
+        .is_set(AppSettings::AllowLeadingHyphen));
     assert!(app
         .subcommands
         .iter()