ENH: Handle -h, shorthelp and help when a Fatal Error happens.

The user may need the help to solve any fatal error that appears while todo.sh isn't properly set up. As the help actions do not depend on any setting that the fatal errors check, we can still invoke them.

Factor out dieWithHelp() and use that for printing the fatal errors.

tests/t2120-shorthelp.sh

@@ -0,0 +1,79 @@
+#!/bin/bash
+#
+
+test_description='shorthelp functionality
+
+This test covers the output of the -h option and the shorthelp action.
+'
+. ./actions-test-lib.sh
+. ./test-lib.sh
+
+# Note: To avoid having to adapt the test whenever the actions change, only
+# check for the section headers.
+test_todo_session '-h output' <<EOF
+>>> todo.sh -h | sed '/^  [A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  See "help" for more details.
+EOF
+
+test_todo_session 'shorthelp output' <<EOF
+>>> todo.sh shorthelp | sed '/^  [A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  See "help" for more details.
+EOF
+
+make_action "foo"
+test_todo_session 'shorthelp output with custom action' <<EOF
+>>> todo.sh -v shorthelp | sed '/^  [A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  Add-on Actions:
+  See "help" for more details.
+EOF
+
+
+# Verify that custom configuration is actually processed (when the -d option
+# precedes the -h option) by specifying a different actions directory and moving
+# our custom action there. The help output should mention the "Add-On Actions".
+set -o pipefail # So that the sed filter doesn't swallow todo.sh's exit code.
+mv todo.cfg custom.cfg
+mv .todo.actions.d custom.actions
+echo 'export TODO_ACTIONS_DIR=$HOME/custom.actions' >> custom.cfg
+
+test_todo_session '-h and fatal error without config' <<EOF
+>>> todo.sh -h | sed '/^ \\{0,2\\}[A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  See "help" for more details.
+Fatal Error: Cannot read configuration file $HOME/.todo/config
+=== 1
+EOF
+
+# Config option comes too late; "Add-on Actions" is *not* mentioned here.
+test_todo_session '-h and fatal error with trailing custom config' <<EOF
+>>> todo.sh -h -d custom.cfg | sed '/^ \\{0,2\\}[A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  See "help" for more details.
+Fatal Error: Cannot read configuration file $HOME/.todo/config
+=== 1
+EOF
+
+# Config option processed; "Add-on Actions" is mentioned here.
+test_todo_session '-h output with preceding custom config' <<EOF
+>>> todo.sh -d custom.cfg -h | sed '/^ \\{0,2\\}[A-Z]/!d'
+  Usage: todo.sh [-fhpantvV] [-d todo_config] action [task_number] [task_description]
+  Actions:
+  Actions can be added and overridden using scripts in the actions
+  Add-on Actions:
+  See "help" for more details.
+EOF
+
+test_done

todo.sh

@@ -81,7 +81,6 @@ shorthelp()
 
 		  See "help" for more details.
 	EndHelpFooter
-    exit 0
 }
 
 help()
@@ -327,6 +326,16 @@ actionUsage()
     done
 }
 
+dieWithHelp()
+{
+    case "$1" in
+        help)       help;;
+        shorthelp)  shorthelp;;
+    esac
+    shift
+
+    die "$@"
+}
 die()
 {
     echo "$*"
@@ -514,6 +523,7 @@ do
         # Cannot just invoke shorthelp() because we need the configuration
         # processed to locate the add-on actions directory.
         set -- '-h' 'shorthelp'
+        OPTIND=2
         ;;
     n )
         OVR_TODOTXT_PRESERVE_LINE_NUMBERS=0
@@ -654,7 +664,7 @@ fi
 }
 
 # === SANITY CHECKS (thanks Karl!) ===
-[ -r "$TODOTXT_CFG_FILE" ] || die "Fatal Error: Cannot read configuration file $TODOTXT_CFG_FILE"
+[ -r "$TODOTXT_CFG_FILE" ] || dieWithHelp "$1" "Fatal Error: Cannot read configuration file $TODOTXT_CFG_FILE"
 
 . "$TODOTXT_CFG_FILE"
 
@@ -693,8 +703,8 @@ fi
 ACTION=${1:-$TODOTXT_DEFAULT_ACTION}
 
 [ -z "$ACTION" ]    && usage
-[ -d "$TODO_DIR" ]  || die "Fatal Error: $TODO_DIR is not a directory"
-( cd "$TODO_DIR" )  || die "Fatal Error: Unable to cd to $TODO_DIR"
+[ -d "$TODO_DIR" ]  || dieWithHelp "$1" "Fatal Error: $TODO_DIR is not a directory"
+( cd "$TODO_DIR" )  || dieWithHelp "$1" "Fatal Error: Unable to cd to $TODO_DIR"
 
 [ -f "$TODO_FILE" ] || cp /dev/null "$TODO_FILE"
 [ -f "$DONE_FILE" ] || cp /dev/null "$DONE_FILE"