[FEATURE] Copy some metadata to subparsers

Author: eseiler

doc/howto/subcommand_parser/index.md

@@ -48,6 +48,16 @@ max$ ./mygit push -h
 then the sub-parser will be named `mygit-push` and will be instantiated with all arguments
 followed by the keyword `push` which in this case triggers printing the help page (`-h`).
 
+Additionally, the following metadata will be copied from the top-level parser to the sub-parser:
+  * sharg::parser::info::version
+  * sharg::parser::info::author
+  * sharg::parser::info::email
+  * sharg::parser::info::date
+  * sharg::parser::info::url
+  * sharg::parser::info::short_copyright
+  * sharg::parser::info::long_copyright
+  * sharg::parser::info::citation
+
 That's it. Here is a full example of a subcommand parser you can try and adjust to your needs:
 
 \include doc/howto/subcommand_parser/subcommand_parse.cpp

include/sharg/auxiliary.hpp

@@ -77,6 +77,20 @@ class vector_of_string : public std::vector<std::string>
  * The meta information is assembled in a struct to provide a central access
  * point that can be easily extended.
  *
+ * ### Subparser
+ *
+ * When \link subcommand_parse using a subparser \endlink, the subcommand will be appended to the
+ * subparser's #app_name.
+ * Additionally, the following metadata will be copied from the top-level parser to the sub-parser:
+ * * #version
+ * * #author
+ * * #email
+ * * #date
+ * * #url
+ * * #short_copyright
+ * * #long_copyright
+ * * #citation
+ *
  * \remark For a complete overview, take a look at \ref parser
  *
  * \stableapi{Since version 1.0.}

include/sharg/parser.hpp

@@ -838,11 +838,24 @@ class parser
             if (subcommands.empty())
                 return false;
 
+            auto copy_metadata_to_subparser = [this](parser & sub_parser)
+            {
+                sub_parser.info.version = info.version;
+                sub_parser.info.author = info.author;
+                sub_parser.info.email = info.email;
+                sub_parser.info.date = info.date;
+                sub_parser.info.url = info.url;
+                sub_parser.info.short_copyright = info.short_copyright;
+                sub_parser.info.long_copyright = info.long_copyright;
+                sub_parser.info.citation = info.citation;
+            };
+
             if (std::ranges::find(subcommands, arg) != subcommands.end())
             {
                 sub_parser = std::make_unique<parser>(info.app_name + "-" + arg.data(),
                                                       std::vector<std::string>{it, arguments.end()},
                                                       update_notifications::off);
+                copy_metadata_to_subparser(get_sub_parser());
 
                 // Add the original calls to the front, e.g. ["raptor"],
                 // s.t. ["raptor", "build"] will be the list after constructing the subparser

test/unit/parser/subcommand_test.cpp

@@ -271,3 +271,56 @@ TEST_F(subcommand_test, recursive_subcommands)
 
     EXPECT_EQ(get_parse_cout_on_exit(sub_sub_parser), expected_sub_sub_full_help);
 }
+
+TEST_F(subcommand_test, copy_meta_data)
+{
+    sharg::parser_meta_data info{.version = "1.0.0",
+                                 .author = "SeqAn-Team",
+                                 .email = "mail@example.org",
+                                 .date = "1970-01-01",
+                                 .url = "example.org",
+                                 .short_copyright = "BSD 3-Clause",
+                                 .long_copyright = "BSD 3-Clause Text",
+                                 .citation = "Cite me!"};
+
+    auto parser = get_subcommand_parser({"index", "--help"}, {"index"});
+    info.app_name = parser.info.app_name;
+    parser.info = info;
+    EXPECT_EQ(parser.info.app_name, "test_parser");
+    ASSERT_EQ(parser.info, info); // Sanity check for test setup
+    EXPECT_NO_THROW(parser.parse());
+
+    auto & sub_parser = parser.get_sub_parser();
+    EXPECT_EQ(sub_parser.info.app_name, "test_parser-index");
+    info.app_name = sub_parser.info.app_name;
+    EXPECT_EQ(sub_parser.info, info);
+
+    std::string expected_sub_full_help = "test_parser-index\n"
+                                         "=================\n"
+                                         "\n"
+                                         "OPTIONS\n"
+                                         "\n"
+                                       + basic_options_str
+                                       + "\n"
+                                         "VERSION\n"
+                                         "    Last update: 1970-01-01\n"
+                                         "    test_parser-index version: 1.0.0\n"
+                                         "    Sharg version: "
+                                       + sharg::sharg_version_cstring
+                                       + "\n"
+                                         "\n"
+                                         "URL\n"
+                                         "    example.org\n"
+                                         "\n"
+                                         "LEGAL\n"
+                                         "    test_parser-index Copyright: BSD 3-Clause\n"
+                                         "    Author: SeqAn-Team\n"
+                                         "    Contact: mail@example.org\n"
+                                         "    SeqAn Copyright: 2006-2025 Knut Reinert, FU-Berlin; released under the\n"
+                                         "    3-clause BSDL.\n"
+                                         "    In your academic works please cite:\n"
+                                         "    [1]   Cite me!\n"
+                                         "    For full copyright and/or warranty information see --copyright.\n";
+
+    EXPECT_EQ(get_parse_cout_on_exit(sub_parser), expected_sub_full_help);
+}