fix(help): Subcommand display order respects Command::next_display_order

Previous behavior:
- They'd be sorted by default
- They'd derive display order if `DeriveDisplayOrder` was set
  - This could be set recursively
- The initial display order value for subcommands was 0

New behavior:
- Sorted order is derived by default
- Sorting is turned on by `cmd.next_display_order(None)`
  - This is not recursive, it must be set on each level
- The display order incrementing is mixed with arguments
  - This does make it slightly more difficult to predict

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - `ErrorKind::EmptyValue` replaced with `ErrorKind::InvalidValue`
 - `ErrorKind::UnrecognizedSubcommand` replaced with `ErrorKind::InvalidSubcommand`
 - `arg!` now sets `ArgAction::SetTrue`, `ArgAction::Count`, `ArgAction::Set`, or `ArgAction::Append` as appropriate
+- *(help)* Subcommand display order respects `Command::next_display_order` instead of `DeriveDisplayOrder` and using its own initial display order value
 - *(env)* Parse `--help` and `--version` like any `ArgAction::SetTrue` flag
 - *(derive)* `subcommand_required(true).arg_required_else_help(true)` is set instead of `SubcommandRequiredElseHelp`
 

examples/derive_ref/interop_tests.md

@@ -112,8 +112,8 @@ OPTIONS:
 
 SUBCOMMANDS:
     add       
-    help      Print this message or the help of the given subcommand(s)
     remove    
+    help      Print this message or the help of the given subcommand(s)
 
 ```
 

examples/git-derive.md

@@ -16,11 +16,11 @@ OPTIONS:
     -h, --help    Print help information
 
 SUBCOMMANDS:
-    add      adds things
     clone    Clones repos
-    help     Print this message or the help of the given subcommand(s)
     push     pushes things
+    add      adds things
     stash    
+    help     Print this message or the help of the given subcommand(s)
 
 $ git-derive help
 git 
@@ -33,11 +33,11 @@ OPTIONS:
     -h, --help    Print help information
 
 SUBCOMMANDS:
-    add      adds things
     clone    Clones repos
-    help     Print this message or the help of the given subcommand(s)
     push     pushes things
+    add      adds things
     stash    
+    help     Print this message or the help of the given subcommand(s)
 
 $ git-derive help add
 git-add 
@@ -89,10 +89,10 @@ OPTIONS:
     -m, --message <MESSAGE>    
 
 SUBCOMMANDS:
+    push     
+    pop      
     apply    
     help     Print this message or the help of the given subcommand(s)
-    pop      
-    push     
 
 $ git-derive stash push -h
 git-stash-push 

examples/git.md

@@ -14,11 +14,11 @@ OPTIONS:
     -h, --help    Print help information
 
 SUBCOMMANDS:
-    add      adds things
     clone    Clones repos
-    help     Print this message or the help of the given subcommand(s)
     push     pushes things
+    add      adds things
     stash    
+    help     Print this message or the help of the given subcommand(s)
 
 $ git help
 git 
@@ -31,11 +31,11 @@ OPTIONS:
     -h, --help    Print help information
 
 SUBCOMMANDS:
-    add      adds things
     clone    Clones repos
-    help     Print this message or the help of the given subcommand(s)
     push     pushes things
+    add      adds things
     stash    
+    help     Print this message or the help of the given subcommand(s)
 
 $ git help add
 git-add 
@@ -87,10 +87,10 @@ OPTIONS:
     -m, --message <MESSAGE>    
 
 SUBCOMMANDS:
+    push     
+    pop      
     apply    
     help     Print this message or the help of the given subcommand(s)
-    pop      
-    push     
 
 $ git stash push -h
 git-stash-push 

examples/multicall-busybox.md

@@ -35,8 +35,8 @@ OPTIONS:
         --install <install>    Install hardlinks for all subcommands in path
 
 APPLETS:
+    true     does nothing successfully
     false    does nothing unsuccessfully
     help     Print this message or the help of the given subcommand(s)
-    true     does nothing successfully
 
 ```

examples/pacman.md

@@ -47,9 +47,9 @@ OPTIONS:
     -V, --version    Print version information
 
 SUBCOMMANDS:
-    help                Print this message or the help of the given subcommand(s)
     query -Q --query    Query the package database.
     sync -S --sync      Synchronize packages.
+    help                Print this message or the help of the given subcommand(s)
 
 $ pacman -S -h
 pacman-sync 

examples/tutorial_builder/01_quick.md

@@ -16,8 +16,8 @@ OPTIONS:
     -V, --version          Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    does testing things
+    help    Print this message or the help of the given subcommand(s)
 
 ```
 

examples/tutorial_derive/01_quick.md

@@ -16,8 +16,8 @@ OPTIONS:
     -V, --version          Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    does testing things
+    help    Print this message or the help of the given subcommand(s)
 
 ```
 

src/builder/command.rs

@@ -402,7 +402,13 @@ impl<'help> Command<'help> {
     #[inline]
     #[must_use]
     pub fn subcommand<S: Into<Self>>(mut self, subcmd: S) -> Self {
-        self.subcommands.push(subcmd.into());
+        let mut subcmd = subcmd.into();
+        if let Some(current_disp_ord) = self.current_disp_ord.as_mut() {
+            let current = *current_disp_ord;
+            subcmd.disp_ord.get_or_insert(current);
+            *current_disp_ord = current + 1;
+        }
+        self.subcommands.push(subcmd);
         self
     }
 
@@ -426,8 +432,12 @@ impl<'help> Command<'help> {
         I: IntoIterator<Item = T>,
         T: Into<Self>,
     {
-        for subcmd in subcmds.into_iter() {
-            self.subcommands.push(subcmd.into());
+        let subcmds = subcmds.into_iter();
+        let (lower, _) = subcmds.size_hint();
+        self.subcommands.reserve(lower);
+
+        for subcmd in subcmds {
+            self = self.subcommand(subcmd);
         }
         self
     }
@@ -4378,9 +4388,6 @@ To change `help`s short, call `cmd.arg(Arg::new(\"help\")...)`.",
             {
                 a.disp_ord.make_explicit();
             }
-            for (i, sc) in &mut self.subcommands.iter_mut().enumerate() {
-                sc.disp_ord.get_or_insert(i);
-            }
         }
         for sc in &mut self.subcommands {
             sc._derive_display_order();

tests/builder/derive_order.rs

@@ -291,3 +291,74 @@ fn prefer_user_help_in_subcommand_with_derive_order() {
         false,
     );
 }
+
+#[test]
+fn subcommand_sorted_display_order() {
+    static SUBCMD_ALPHA_ORDER: &str = "test 1
+
+USAGE:
+    test [SUBCOMMAND]
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+SUBCOMMANDS:
+    a1      blah a1
+    b1      blah b1
+    help    Print this message or the help of the given subcommand(s)
+";
+
+    let app_subcmd_alpha_order = Command::new("test")
+        .version("1")
+        .next_display_order(None)
+        .subcommands(vec![
+            Command::new("b1")
+                .about("blah b1")
+                .arg(Arg::new("test").short('t')),
+            Command::new("a1")
+                .about("blah a1")
+                .arg(Arg::new("roster").short('r')),
+        ]);
+
+    utils::assert_output(
+        app_subcmd_alpha_order,
+        "test --help",
+        SUBCMD_ALPHA_ORDER,
+        false,
+    );
+}
+
+#[test]
+fn subcommand_derived_display_order() {
+    static SUBCMD_DECL_ORDER: &str = "test 1
+
+USAGE:
+    test [SUBCOMMAND]
+
+OPTIONS:
+    -h, --help       Print help information
+    -V, --version    Print version information
+
+SUBCOMMANDS:
+    b1      blah b1
+    a1      blah a1
+    help    Print this message or the help of the given subcommand(s)
+";
+
+    let app_subcmd_decl_order = Command::new("test").version("1").subcommands(vec![
+        Command::new("b1")
+            .about("blah b1")
+            .arg(Arg::new("test").short('t')),
+        Command::new("a1")
+            .about("blah a1")
+            .arg(Arg::new("roster").short('r')),
+    ]);
+
+    utils::assert_output(
+        app_subcmd_decl_order,
+        "test --help",
+        SUBCMD_DECL_ORDER,
+        false,
+    );
+}

tests/builder/help.rs

@@ -43,8 +43,8 @@ OPTIONS:
     -V, --version                    Print version information
 
 SUBCOMMANDS:
-    help      Print this message or the help of the given subcommand(s)
     subcmd    tests subcommands
+    help      Print this message or the help of the given subcommand(s)
 ";
 
 static SC_NEGATES_REQS: &str = "prog 1.0
@@ -62,8 +62,8 @@ OPTIONS:
     -V, --version       Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static ARGS_NEGATE_SC: &str = "prog 1.0
@@ -82,8 +82,8 @@ OPTIONS:
     -V, --version       Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static AFTER_HELP: &str = "some text that comes before the help
@@ -410,8 +410,8 @@ OPTIONS:
     -V, --version    Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    some
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static LAST_ARG_REQ: &str = "last 0.1
@@ -445,8 +445,8 @@ OPTIONS:
     -V, --version    Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    some
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static HIDE_DEFAULT_VAL: &str = "default 0.1
@@ -602,8 +602,8 @@ OPTIONS:
     -h, --help    Print help information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     sub     short about sub
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 fn setup() -> Command<'static> {

tests/builder/subcommands.rs

@@ -12,8 +12,8 @@ OPTIONS:
     -V, --version    Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    Some help [aliases: dongle, done]
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static INVISIBLE_ALIAS_HELP: &str = "clap-test 2.6
@@ -26,37 +26,7 @@ OPTIONS:
     -V, --version    Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    Some help
-";
-
-static SUBCMD_ALPHA_ORDER: &str = "test 1
-
-USAGE:
-    test [SUBCOMMAND]
-
-OPTIONS:
-    -h, --help       Print help information
-    -V, --version    Print version information
-
-SUBCOMMANDS:
-    a1      blah a1
-    b1      blah b1
-    help    Print this message or the help of the given subcommand(s)
-";
-
-static SUBCMD_DECL_ORDER: &str = "test 1
-
-USAGE:
-    test [SUBCOMMAND]
-
-OPTIONS:
-    -h, --help       Print help information
-    -V, --version    Print version information
-
-SUBCOMMANDS:
-    b1      blah b1
-    a1      blah a1
     help    Print this message or the help of the given subcommand(s)
 ";
 
@@ -169,44 +139,6 @@ fn subcommand_multiple() {
     );
 }
 
-#[test]
-fn subcommand_display_order() {
-    let app_subcmd_alpha_order = Command::new("test").version("1").subcommands(vec![
-        Command::new("b1")
-            .about("blah b1")
-            .arg(Arg::new("test").short('t')),
-        Command::new("a1")
-            .about("blah a1")
-            .arg(Arg::new("roster").short('r')),
-    ]);
-
-    utils::assert_output(
-        app_subcmd_alpha_order,
-        "test --help",
-        SUBCMD_ALPHA_ORDER,
-        false,
-    );
-
-    let app_subcmd_decl_order = Command::new("test")
-        .version("1")
-        .setting(clap::AppSettings::DeriveDisplayOrder)
-        .subcommands(vec![
-            Command::new("b1")
-                .about("blah b1")
-                .arg(Arg::new("test").short('t')),
-            Command::new("a1")
-                .about("blah a1")
-                .arg(Arg::new("roster").short('r')),
-        ]);
-
-    utils::assert_output(
-        app_subcmd_decl_order,
-        "test --help",
-        SUBCMD_DECL_ORDER,
-        false,
-    );
-}
-
 #[test]
 fn single_alias() {
     let m = Command::new("myprog")

tests/builder/template_help.rs

@@ -40,8 +40,8 @@ OPTIONS:
 ARGS:
     <output>    Sets an optional output file
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    does testing things
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 static SIMPLE_TEMPLATE: &str = "MyApp 1.0
@@ -61,8 +61,8 @@ OPTIONS:
     -V, --version          Print version information
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     test    does testing things
+    help    Print this message or the help of the given subcommand(s)
 ";
 
 #[test]

tests/ui/arg_required_else_help_stderr.toml

@@ -14,6 +14,6 @@ OPTIONS:
         --verbose    log
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     more    
+    help    Print this message or the help of the given subcommand(s)
 """

tests/ui/h_flag_stdout.toml

@@ -13,7 +13,7 @@ OPTIONS:
         --verbose    log
 
 SUBCOMMANDS:
-    help    Print this message or the help of the given subcommand(s)
     more    
+    help    Print this message or the help of the given subcommand(s)
 """
 stderr = ""

tests/ui/help_cmd_stdout.toml

@@ -18,9 +18,9 @@ OPTIONS:
             more log
 
 SUBCOMMANDS:
-    help
-            Print this message or the help of the given subcommand(s)
     more
             
+    help
+            Print this message or the help of the given subcommand(s)
 """
 stderr = ""

tests/ui/help_flag_stdout.toml

@@ -18,9 +18,9 @@ OPTIONS:
             more log
 
 SUBCOMMANDS:
-    help
-            Print this message or the help of the given subcommand(s)
     more
             
+    help
+            Print this message or the help of the given subcommand(s)
 """
 stderr = ""