Fix usage message for `--roll-forward-on-no-candidate-fx` (dotnet/core-setup#4878)

Fix usage message for roll-forward-on-no-candidate-fx to make it clear that it requires a value.
Made the descriptions consistent with those reported by CLI (dots at the end).
In case of parsing error, show the argument descriptions as well, not just the names and values.

Commit migrated from https://github.com/dotnet/core-setup/commit/c2c71ca8a4534ecc53dcd8bb1ece1bc2e1af8f97

diff --git a/src/installer/corehost/cli/fxr/fx_muxer.cpp b/src/installer/corehost/cli/fxr/fx_muxer.cpp
index 44df04f..23b114e 100644 (file)
--- a/src/installer/corehost/cli/fxr/fx_muxer.cpp
+++ b/src/installer/corehost/cli/fxr/fx_muxer.cpp
@@ -638,10 +638,10 @@ void fx_muxer_t::muxer_usage(bool is_sdk_present)
 
     for (const auto& arg : known_opts)
     {
-        trace::println(_X("  %-34s  %s"), (arg.option + _X(" ") + arg.argument).c_str(), arg.description.c_str());
+        trace::println(_X("  %-37s  %s"), (arg.option + _X(" ") + arg.argument).c_str(), arg.description.c_str());
     }
-    trace::println(_X("  --list-runtimes                     Display the installed runtimes"));
-    trace::println(_X("  --list-sdks                         Display the installed SDKs"));
+    trace::println(_X("  --list-runtimes                        Display the installed runtimes"));
+    trace::println(_X("  --list-sdks                            Display the installed SDKs"));
 
     if (!is_sdk_present)
     {
@@ -698,19 +698,19 @@ void append_probe_realpath(const pal::string_t& path, std::vector<pal::string_t>
 
 std::vector<host_option> fx_muxer_t::get_known_opts(bool exec_mode, host_mode_t mode, bool get_all_options)
 {
-    std::vector<host_option> known_opts = { { _X("--additionalprobingpath"), _X("<path>"), _X("Path containing probing policy and assemblies to probe for") } };
+    std::vector<host_option> known_opts = { { _X("--additionalprobingpath"), _X("<path>"), _X("Path containing probing policy and assemblies to probe for.") } };
     if (get_all_options || exec_mode || mode == host_mode_t::split_fx || mode == host_mode_t::apphost)
     {
-        known_opts.push_back({ _X("--depsfile"), _X("<path>"), _X("Path to <application>.deps.json file")});
-        known_opts.push_back({ _X("--runtimeconfig"), _X("<path>"), _X("Path to <application>.runtimeconfig.json file")});
+        known_opts.push_back({ _X("--depsfile"), _X("<path>"), _X("Path to <application>.deps.json file.")});
+        known_opts.push_back({ _X("--runtimeconfig"), _X("<path>"), _X("Path to <application>.runtimeconfig.json file.")});
     }
 
     if (get_all_options || mode == host_mode_t::muxer || mode == host_mode_t::apphost)
     {
         // If mode=host_mode_t::apphost, these are only used when the app is framework-dependent.
         known_opts.push_back({ _X("--fx-version"), _X("<version>"), _X("Version of the installed Shared Framework to use to run the application.")});
-        known_opts.push_back({ _X("--roll-forward-on-no-candidate-fx"), _X(""), _X("Roll forward on no candidate shared framework is enabled")});
-        known_opts.push_back({ _X("--additional-deps"), _X("<path>"), _X("Path to additonal deps.json file")});
+        known_opts.push_back({ _X("--roll-forward-on-no-candidate-fx"), _X("<n>"), _X("Roll forward on no candidate framework (0=off, 1=roll minor, 2=roll major & minor).")});
+        known_opts.push_back({ _X("--additional-deps"), _X("<path>"), _X("Path to additional deps.json file.")});
     }
 
     return known_opts;
@@ -737,7 +737,7 @@ int fx_muxer_t::parse_args(
         trace::error(_X("Failed to parse supported options or their values:"));
         for (const auto& arg : known_opts)
         {
-            trace::error(_X("  %s"), (arg.option + _X(" ") + arg.argument).c_str());
+            trace::error(_X("  %-37s  %s"), (arg.option + _X(" ") + arg.argument).c_str(), arg.description.c_str());
         }
         return InvalidArgFailure;
     }