test: add coverage for help flag hints

tests/builder/help.rs

@@ -81,14 +81,17 @@ fn help_multi_subcommand_error() {
         .try_get_matches_from(["ctest", "help", "subcmd", "multi", "foo"])
         .unwrap_err();
 
-    assert_data_eq!(err.to_string(), str![[r#"
+    assert_data_eq!(
+        err.to_string(),
+        str![[r#"
 error: unrecognized subcommand 'foo'
 
 Usage: ctest subcmd multi [OPTIONS]
 
 For more information, try '--help'.
 
-"#]]);
+"#]]
+    );
 }
 
 #[test]
@@ -351,6 +354,152 @@ Options:
     utils::assert_output(cmd, "ctest --help", DEFAULT_HELP, false);
 }
 
+#[test]
+fn try_help_default() {
+    static DEFAULT_HELP: &str = "\
+error: unexpected argument 'bar' found
+
+Usage: ctest
+
+For more information, try '--help'.
+";
+
+    let cmd = Command::new("ctest").version("1.0").term_width(0);
+    utils::assert_output(cmd, "ctest bar", DEFAULT_HELP, true);
+}
+
+#[test]
+fn try_help_custom_flag() {
+    static EXPECTED_HELP: &str = "\
+error: unexpected argument 'bar' found
+
+Usage: ctest
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        .arg(
+            Arg::new("help")
+                .long("help")
+                .short('h')
+                .action(ArgAction::Help),
+        )
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
+#[test]
+fn try_help_custom_flag_short() {
+    static EXPECTED_HELP: &str = "\
+error: unexpected argument 'bar' found
+
+Usage: ctest
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        .arg(Arg::new("help").short('h').action(ArgAction::HelpShort))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
+#[test]
+fn try_help_custom_flag_long() {
+    static EXPECTED_HELP: &str = "\
+error: unexpected argument 'bar' found
+
+Usage: ctest
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        .arg(Arg::new("help").long("help").action(ArgAction::HelpShort))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
+#[test]
+fn try_help_custom_flag_no_action() {
+    static EXPECTED_HELP: &str = "\
+error: unexpected argument 'bar' found
+
+Usage: ctest
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        // Note `ArgAction::Help` is excluded
+        .arg(Arg::new("help").long("help").global(true))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
+#[test]
+fn try_help_subcommand_default() {
+    static DEFAULT_HELP: &str = "\
+error: unrecognized subcommand 'bar'
+
+Usage: ctest [COMMAND]
+
+For more information, try '--help'.
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .subcommand(Command::new("foo"))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", DEFAULT_HELP, true);
+}
+
+#[test]
+fn try_help_subcommand_custom_flag() {
+    static EXPECTED_HELP: &str = "\
+error: unrecognized subcommand 'bar'
+
+Usage: ctest [COMMAND]
+
+For more information, try 'help'.
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        .arg(
+            Arg::new("help")
+                .long("help")
+                .short('h')
+                .action(ArgAction::Help)
+                .global(true),
+        )
+        .subcommand(Command::new("foo"))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
+#[test]
+fn try_help_subcommand_custom_flag_no_action() {
+    static EXPECTED_HELP: &str = "\
+error: unrecognized subcommand 'bar'
+
+Usage: ctest [COMMAND]
+
+For more information, try 'help'.
+";
+
+    let cmd = Command::new("ctest")
+        .version("1.0")
+        .disable_help_flag(true)
+        // Note `ArgAction::Help` is excluded
+        .arg(Arg::new("help").long("help").global(true))
+        .subcommand(Command::new("foo"))
+        .term_width(0);
+    utils::assert_output(cmd, "ctest bar", EXPECTED_HELP, true);
+}
+
 #[test]
 #[cfg(feature = "wrap_help")]
 fn wrapped_help() {
@@ -2861,15 +3010,18 @@ fn parent_cmd_req_in_usage_with_render_help() {
     let subcmd = cmd.find_subcommand_mut("test").unwrap();
 
     let help = subcmd.render_help().to_string();
-    assert_data_eq!(help, str![[r#"
+    assert_data_eq!(
+        help,
+        str![[r#"
 some
 
 Usage: parent <TARGET> <ARGS> test
 
 Options:
   -h, --help  Print help
 
-"#]]);
+"#]]
+    );
 }
 
 #[test]

tests/builder/subcommands.rs

@@ -487,20 +487,25 @@ fn bad_multicall_command_error() {
 
     let err = cmd.clone().try_get_matches_from(["world"]).unwrap_err();
     assert_eq!(err.kind(), ErrorKind::InvalidSubcommand);
-    assert_data_eq!(err.to_string(), str![[r#"
+    assert_data_eq!(
+        err.to_string(),
+        str![[r#"
 error: unrecognized subcommand 'world'
 
 Usage: <COMMAND>
 
 For more information, try 'help'.
 
-"#]]);
+"#]]
+    );
 
     #[cfg(feature = "suggestions")]
     {
         let err = cmd.clone().try_get_matches_from(["baz"]).unwrap_err();
         assert_eq!(err.kind(), ErrorKind::InvalidSubcommand);
-        assert_data_eq!(err.to_string(), str![[r#"
+        assert_data_eq!(
+            err.to_string(),
+            str![[r#"
 error: unrecognized subcommand 'baz'
 
   tip: a similar subcommand exists: 'bar'
@@ -509,7 +514,8 @@ Usage: <COMMAND>
 
 For more information, try 'help'.
 
-"#]]);
+"#]]
+        );
     }
 
     // Verify whatever we did to get the above to work didn't disable `--help` and `--version`.
@@ -600,7 +606,9 @@ fn multicall_render_help() {
     let subcmd = subcmd.find_subcommand_mut("bar").unwrap();
 
     let help = subcmd.render_help().to_string();
-    assert_data_eq!(help, str![[r#"
+    assert_data_eq!(
+        help,
+        str![[r#"
 Usage: foo bar [value]
 
 Arguments:
@@ -610,7 +618,8 @@ Options:
   -h, --help     Print help
   -V, --version  Print version
 
-"#]]);
+"#]]
+    );
 }
 
 #[test]