feat(set): more featureful completion

Complete option flags, with plus and dash prefixes, setopt values only
after `-o`/`+o`, allow filename completions if not preceded by `-` or
`--`.

Closes #103

bash_completion

@@ -112,9 +112,6 @@ complete -j -P '"%' -S '"' fg jobs disown
 # readonly and unset complete with shell variables
 complete -v readonly unset
 
-# set completes with set options
-complete -A setopt set
-
 # shopt completes with shopt options
 complete -A shopt shopt
 

completions/Makefile.am

@@ -398,6 +398,7 @@ bashcomp_DATA = 2to3 \
 		screen \
 		scrub \
 		secret-tool \
+		set \
 		sh \
 		sha256sum \
 		shellcheck \

completions/set

@@ -0,0 +1,50 @@
+# bash completion for set                                 -*- shell-script -*-
+
+_comp_cmd_set()
+{
+    local cur prev words cword comp_args
+    _comp_initialize -- "$@" || return
+
+    local noargopts='!(-*|*[o]*)'
+
+    # shellcheck disable=SC2254
+    case "$prev" in
+        [+-]${noargopts}o)
+            _comp_compgen -- -A setopt
+            return
+            ;;
+    esac
+
+    local i want_options=set
+    for ((i = 1; i < cword; i++)); do
+        if [[ ${words[i]} == -?(-) ]]; then
+            want_options=""
+            break
+        fi
+    done
+
+    if [[ $want_options && $cur == [+-]* ]]; then
+        local has_plus=""
+        if [[ $cur == +?([a-zA-Z]) ]]; then
+            has_plus=set
+            cur=${cur/#+/-}
+        fi
+        _comp_compgen_usage
+        if [[ $has_plus ]]; then
+            local i
+            for i in "${!COMPREPLY[@]}"; do
+                if [[ ${COMPREPLY[i]} == -- ]]; then
+                    unset -v 'COMPREPLY[i]'
+                else
+                    COMPREPLY[i]=${COMPREPLY[i]/#-/+}
+                fi
+            done
+        fi
+        return
+    fi
+
+    _comp_compgen_filedir
+} &&
+    complete -F _comp_cmd_set set
+
+# ex: filetype=sh

test/t/test_set.py

@@ -1,7 +1,26 @@
 import pytest
 
+from conftest import assert_complete
+
 
 class TestSet:
-    @pytest.mark.complete("set no")
-    def test_1(self, completion):
+    @pytest.mark.parametrize("dash", ["", "-", "--"])
+    def test_basic(self, bash, dash):
+        completion = assert_complete(bash, f"set {dash} ")
         assert completion
+
+    @pytest.mark.parametrize("prefix", ["-", "+"])
+    def test_options(self, bash, prefix):
+        completion = assert_complete(bash, f"set {prefix}")
+        assert f"{prefix}o" in completion
+        assert "+-" not in completion
+
+    @pytest.mark.parametrize("prefix", ["-", "+"])
+    def test_o_args(self, bash, prefix):
+        completion = assert_complete(bash, f"set {prefix}o ")
+        assert any(x.startswith("no") for x in completion)
+
+    @pytest.mark.parametrize("dash,prefix", [["-", "--"], ["-", "+"]])
+    def test_options_after_dash_or_dashdash(self, bash, dash, prefix):
+        completion = assert_complete(bash, f"set {dash} {prefix}")
+        assert not completion