test: Add tests for subcommand headings

- add tests for subcommand headings feature
- include tests for single and multiple help headers
- add test for hiding commands header
- add test for mixed standard and custom headers

Author: gortavoher

tests/builder/subcommands.rs

@@ -635,3 +635,184 @@ fn duplicate_subcommand_alias() {
         .subcommand(Command::new("unique").alias("repeat"))
         .build();
 }
+
+#[test]
+fn test_help_header() {
+    static VISIBLE_ALIAS_HELP: &str = "\
+    Usage: clap-test [COMMAND]
+    
+    Commands:
+    help  Print this message or the help of the given subcommand(s)
+    
+    Test commands:
+    test  Some help
+    
+    Options:
+    -h, --help     Print help
+    -V, --version  Print version
+    ";
+    
+    let cmd = Command::new("clap-test")
+    .version("2.6")
+    .subcommand(
+        Command::new("test")
+        .about("Some help")
+        .help_heading("Test commands"),
+    );
+    utils::assert_output(cmd, "clap-test --help", VISIBLE_ALIAS_HELP, false);
+}
+
+#[test]
+fn test_help_header_multiple_help_headers() {
+    static VISIBLE_ALIAS_HELP: &str = "\
+Usage: clap-test [COMMAND]
+
+Commands:
+  help   Print this message or the help of the given subcommand(s)
+
+Test Commands 1:
+  test1  Some help
+
+Test Commands 2:
+  test2  Some help
+
+Options:
+  -h, --help     Print help
+  -V, --version  Print version
+";
+
+    let cmd = Command::new("clap-test")
+        .version("2.6")
+        .subcommand(
+            Command::new("test1")
+                .about("Some help")
+                .help_heading("Test Commands 1"),
+        )
+        .subcommand(
+            Command::new("test2")
+                .about("Some help")
+                .help_heading("Test Commands 2"),
+        );
+
+    utils::assert_output(cmd, "clap-test --help", VISIBLE_ALIAS_HELP, false);
+}
+
+#[test]
+fn test_help_header_hide_commands_header() {
+    static VISIBLE_ALIAS_HELP: &str = "\
+Usage: clap-test [COMMAND]
+
+Test commands:
+  test  Some help
+
+Options:
+  -h, --help     Print help
+  -V, --version  Print version
+";
+
+    let cmd = Command::new("clap-test")
+        .version("2.6")
+        .disable_help_subcommand(true)
+        .subcommand_help_heading("Test commands")
+        .subcommand(Command::new("test").about("Some help"));
+    utils::assert_output(cmd, "clap-test --help", VISIBLE_ALIAS_HELP, false);
+}
+
+#[test]
+fn test_multiple_commands_mixed_standard_and_custom_headers() {
+    static VISIBLE_ALIAS_HELP: &str = "\
+Usage: clap-test [COMMAND]
+
+Help Section:
+  help      Print this message or the help of the given subcommand(s)
+
+Commands:
+  def_cmd1  First command under default command heading
+  def_cmd2  Second command under default command heading
+  def_cmd3  Third command under default command heading
+  def_cmd4  Fourth command under default command heading
+
+First Custom:
+  ch1_cmd1  First command under first custom command heading
+  ch1_cmd2  Second command under first custom command heading
+  ch1_cmd3  Third command under first custom command heading
+  ch1_cmd4  Fourth command under first custom command heading
+
+Second Custom:
+  ch2_cmd1  First command under second custom command heading
+  ch2_cmd2  Second command under second custom command heading
+  ch2_cmd3  Third command under second custom command heading
+  ch2_cmd4  Fourth command under second custom command heading
+
+Options:
+  -h, --help     Print help
+  -V, --version  Print version
+";
+
+    let cmd = Command::new("clap-test")
+        .version("2.6")
+        .subcommand_help_heading("Help Section")
+        .subcommand(
+            Command::new("def_cmd1")
+                .about("First command under default command heading")
+                .help_heading("Commands"),
+        )
+        .subcommand(
+            Command::new("def_cmd2")
+                .about("Second command under default command heading")
+                .help_heading("Commands"),
+        )
+        .subcommand(
+            Command::new("def_cmd3")
+                .about("Third command under default command heading")
+                .help_heading("Commands"),
+        )
+        .subcommand(
+            Command::new("def_cmd4")
+                .about("Fourth command under default command heading")
+                .help_heading("Commands"),
+        )
+        .subcommand(
+            Command::new("ch1_cmd1")
+                .about("First command under first custom command heading")
+                .help_heading("First Custom"),
+        )
+        .subcommand(
+            Command::new("ch1_cmd2")
+                .about("Second command under first custom command heading")
+                .help_heading("First Custom"),
+        )
+        .subcommand(
+            Command::new("ch1_cmd3")
+                .about("Third command under first custom command heading")
+                .help_heading("First Custom"),
+        )
+        .subcommand(
+            Command::new("ch1_cmd4")
+                .about("Fourth command under first custom command heading")
+                .help_heading("First Custom"),
+        )
+        .subcommand(
+            Command::new("ch2_cmd1")
+                .about("First command under second custom command heading")
+                .help_heading("Second Custom"),
+        )
+        .subcommand(
+            Command::new("ch2_cmd2")
+                .about("Second command under second custom command heading")
+                .help_heading("Second Custom"),
+        )
+        .subcommand(
+            Command::new("ch2_cmd3")
+                .about("Third command under second custom command heading")
+                .help_heading("Second Custom"),
+        )
+        .subcommand(
+            Command::new("ch2_cmd4")
+                .about("Fourth command under second custom command heading")
+                .help_heading("Second Custom"),
+        );
+
+    utils::assert_output(cmd, "clap-test --help", VISIBLE_ALIAS_HELP, false);
+}
+