Improve micromamba bash completion (#1234)

docs/source/installation.rst

@@ -144,3 +144,29 @@ Windows
   # and use micromamba directly
   micromamba create -f ./test/env_win.yaml -y
   micromamba activate yourenv
+
+
+.. _shell_completion:
+
+Shell completion
+================
+
+For now, only ``micromamba`` provides shell completion on ``bash``.
+
+To activate it, it's as simple as running:
+
+.. code::
+
+  micromamba shell completion
+
+.. note::
+  This command will only work on ``bash``
+
+The completion is now available in any new shell opened or in the current shell after running ``source ~/.bashrc`` to take modifications into account.
+
+| Just hit ``<TAB><TAB>`` to get completion when typing your command.
+| For example the following command will help you to pick a named environment to activate:
+
+.. code::
+
+  micromamba activate <TAB><TAB>

src/micromamba/completer.bash

@@ -5,6 +5,6 @@ _umamba_completions()
   COMPREPLY=($(micromamba completer "${COMP_WORDS[@]:1}"))
 }
 
-complete -F _umamba_completions micromamba
+complete -o default -F _umamba_completions micromamba
 # <<< umamba completion <<<
 )MAMBARAW"

src/micromamba/completer.cpp

@@ -83,6 +83,20 @@ overwrite_callbacks(std::vector<CLI::App*>& apps,
     }
 }
 
+void
+add_activate_completion(CLI::App* app, std::vector<std::string>& completer_args, bool& completed)
+{
+    CLI::App* activate_subcom
+        = app->add_subcommand("activate", "Mock activate shell function for completion");
+    activate_subcom->callback([app, &completer_args, &completed]() {
+        if (completer_args.size() == 1)
+        {
+            completer_args = { "-n", completer_args.back() };
+            complete_options(app, completer_args, completed);
+        }
+    });
+}
+
 void
 get_completions(CLI::App* app, int argc, char** argv)
 {
@@ -100,6 +114,7 @@ get_completions(CLI::App* app, int argc, char** argv)
 
     std::vector<CLI::App*> apps = { app };
     overwrite_callbacks(apps, completer_args, completed);
+    add_activate_completion(app, completer_args, completed);
     argv[1] = argv[0];
 
     try