feat(reportbug): parse various option args from option help

completions/reportbug

@@ -27,41 +27,19 @@ _reportbug()
                 done)' -- "$cur"))
             return
             ;;
-        --bts | -!(-*)B)
-            COMPREPLY=($(compgen -W "debian guug kde mandrake help" -- \
-                "$cur"))
+        --tag | --ui | --interface | --type | --bts | --severity | --mode | -!(-*)[TutBS])
+            COMPREPLY+=($(
+                compgen -W \
+                    '$("$1" $prev help 2>&1 </dev/null | sed -ne "/^[[:space:]]/p")' \
+                    -- "$cur"
+            ))
             return
             ;;
         --editor | --mua | --mbox-reader-cmd | -!(-*)e)
             compopt -o filenames
             COMPREPLY=($(compgen -c -- "$cur"))
             return
             ;;
-        --mode)
-            COMPREPLY=($(compgen -W "novice standard expert" -- "$cur"))
-            return
-            ;;
-        --severity | -!(-*)S)
-            COMPREPLY=($(compgen -W "grave serious important normal minor
-                wishlist" -- "$cur"))
-            return
-            ;;
-        --ui | --interface | -!(-*)u)
-            COMPREPLY=($(compgen -W "newt text gnome" -- "$cur"))
-            return
-            ;;
-        --type | -!(-*)t)
-            COMPREPLY=($(compgen -W "gnats debbugs" -- "$cur"))
-            return
-            ;;
-        --tag | -!(-*)T)
-            COMPREPLY=($(compgen -W "none woody potato sarge sarge-ignore
-                etch etch-ignore lenny lenny-ignore sid experimental confirmed
-                d-i fixed fixed-in-experimental fixed-upstream help l10n
-                moreinfo patch pending security unreproducible upstream wontfix
-                ipv6 lfs" -- "$cur"))
-            return
-            ;;
         --from-buildd)
             COMPREPLY=($(compgen -S "_" -W '$(apt-cache dumpavail | \
                 command grep "^Source: $cur" | sort -u | cut -f2 -d" ")'))

test/t/test_reportbug.py

@@ -5,3 +5,7 @@ class TestReportbug:
     @pytest.mark.complete("reportbug --m", require_cmd=True)
     def test_1(self, completion):
         assert completion
+
+    @pytest.mark.complete("reportbug --bts=", require_cmd=True)
+    def test_bts(self, completion):
+        assert "default" in completion