ENH: Enable file completion for add-on actions via _todo_file{1,2,3}_actions (#270)

* Refactoring: Use regular expression match instead of case globbing for actions taking a SRC argument

Making it consistent with the test for MOVE_COMMAND_PATTERN, and allowing to extend the pattern with custom actions in the future.

* Refactoring: Move the anchoring and grouping out of MOVE_COMMAND_PATTERN

So that additional (custom) add-on actions can be configured in the future.

* ENH: Enable file completion for add-on actions via _todo_file{1,2,3}_actions

Allowing completion of todo files directly after the add-on action (1), with one (2) / two (3) arguments in between. This should handle most cases.

In order to configure the add-on completion, the corresponding configuration variable has to be defined in the user's shell (e.g. via ~/.bashrc):
_todo_file1_actions='myaction|anotheraction'

tests/t6060-completion-addon-files.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+#
+
+test_description='Bash add-on action file completion functionality
+
+This test checks todo_completion of files for add-on actions that have file argument(s) configured
+'
+. ./test-lib.sh
+
+readonly FILES='done.txt report.txt todo.txt'
+test_todo_completion 'nothing after unconfigured bar' 'todo.sh bar ' ''
+
+_todo_file1_actions='foo|bar'
+test_todo_completion 'all files after configured bar' 'todo.sh bar ' "$FILES"
+test_todo_completion 'nothing after configured bar ITEM#' 'todo.sh bar 1 ' ''
+
+_todo_file2_actions='baz'
+test_todo_completion 'nothing after configured baz' 'todo.sh baz ' ''
+test_todo_completion 'all files after configured baz ITEM#' 'todo.sh baz 1 ' "$FILES"
+test_todo_completion 'nothing after configured baz ITEM# MORE' 'todo.sh baz 1 more ' ''
+
+_todo_file3_actions='biz'
+test_todo_completion 'nothing after configured biz' 'todo.sh biz ' ''
+test_todo_completion 'nothing after configured biz ITEM#' 'todo.sh biz 1 ' ''
+test_todo_completion 'all files after configured biz ITEM# MORE' 'todo.sh biz 1 more ' "$FILES"
+test_todo_completion 'nothing after configured biz ITEM# EVEN MORE' 'todo.sh biz 1 even more ' ''
+
+test_done

todo_completion

@@ -14,15 +14,15 @@ _todo()
         rm depri dp do help list ls listaddons listall lsa listcon  \
         lsc listfile lf listpri lsp listproj lsprj move \
         mv prepend prep pri p replace report shorthelp"
-    local -r MOVE_COMMAND_PATTERN='^(move|mv)$'
+    local -r MOVE_COMMAND_PATTERN='move|mv'
 
     local _todo_sh=${_todo_sh:-todo.sh}
     local completions
     if [ $COMP_CWORD -eq 1 ]; then
         completions="$COMMANDS $(eval TODOTXT_VERBOSE=0 $_todo_sh command listaddons 2>/dev/null) $OPTS"
     elif [[ $COMP_CWORD -gt 2 && ( \
-        "${COMP_WORDS[COMP_CWORD-2]}" =~ $MOVE_COMMAND_PATTERN || \
+        "${COMP_WORDS[COMP_CWORD-2]}" =~ ^($MOVE_COMMAND_PATTERN${_todo_file2_actions:+|${_todo_file2_actions}})$ || \
-        "${COMP_WORDS[COMP_CWORD-3]}" =~ $MOVE_COMMAND_PATTERN ) ]]; then
+        "${COMP_WORDS[COMP_CWORD-3]}" =~ ^($MOVE_COMMAND_PATTERN${_todo_file3_actions:+|${_todo_file3_actions}})$ ) ]]; then
         # "move ITEM# DEST [SRC]" has file arguments on positions 2 and 3.
         completions=$(eval TODOTXT_VERBOSE=0 $_todo_sh command listfile 2>/dev/null)
     else
@@ -31,10 +31,11 @@ _todo()
                 completions=$COMMANDS;;
             help)
                 completions="$COMMANDS $(eval TODOTXT_VERBOSE=0 $_todo_sh command listaddons 2>/dev/null)";;
-            addto|listfile|lf)
-                completions=$(eval TODOTXT_VERBOSE=0 $_todo_sh command listfile 2>/dev/null);;
             -*) completions="$COMMANDS $(eval TODOTXT_VERBOSE=0 $_todo_sh command listaddons 2>/dev/null) $OPTS";;
-            *)  case "$cur" in
+            *)  if [[ "$prev" =~ ^(addto|listfile|lf${_todo_file1_actions:+|${_todo_file1_actions}})$ ]]; then
+                    completions=$(eval TODOTXT_VERBOSE=0 $_todo_sh command listfile 2>/dev/null)
+                else
+                    case "$cur" in
                         +*) completions=$(eval TODOTXT_VERBOSE=0 $_todo_sh command listproj 2>/dev/null)
                             COMPREPLY=( $( compgen -W "$completions" -- $cur ))
                             [ ${#COMPREPLY[@]} -gt 0 ] && return 0
@@ -81,6 +82,7 @@ _todo()
                             fi
                             ;;
                     esac
+                fi
                 ;;
         esac
     fi