mesh_search: filler words of a question (did, our, on, all) need not match, so the operator's own words find a tool; a query of filler finds nothing

node-tools/internal/console/search.go

@@ -44,6 +44,31 @@ var synonyms = map[string][]string{
 	"hosts":     {"hostname"},
 }
 
+// filler are the function words a question carries and no tool is named for: a query's words must all
+// match, so "did our weekly upgrade run on all our nodes" would otherwise find nothing for "did", "our",
+// "on" and "all". Kept short and here only; a word that names something (`every`, `list`, `not`) is not
+// in it. A query of nothing but these matches nothing.
+var filler = map[string]bool{}
+
+func init() {
+	for _, w := range strings.Fields("a an the did do does our my your we i is are was on in at of for to all any and or with it its there what which how has have been") {
+		filler[w] = true
+	}
+}
+
+// queryWords are a query's words to match: split at spaces, the punctuation of a sentence trimmed from
+// each end (`nodes?` is `nodes`), filler left out.
+func queryWords(query string) []string {
+	var out []string
+	for _, w := range strings.Fields(query) {
+		w = strings.Trim(w, "?!.,;:\"'()")
+		if w != "" && !filler[w] {
+			out = append(out, w)
+		}
+	}
+	return out
+}
+
 // hit is one match as mesh_search answers it.
 type hit struct {
 	Address string `json:"address"`
@@ -169,8 +194,11 @@ func scoreOf(query string, qwords []string, name, description string, replaces [
 // search is mesh_search's answer: every match, best first.
 func (x *index) search(query string) []hit {
 	query = strings.ToLower(strings.TrimSpace(query))
-	qwords := strings.Fields(query)
+	qwords := queryWords(query)
 	var hits []hit
+	if len(qwords) == 0 {
+		return nil
+	}
 	for _, st := range x.Seats {
 		for _, v := range st.Verbs {
 			replaces := x.Replaces["seat:"+st.Seat+"."+v.Name]

node-tools/internal/console/search_test.go

@@ -149,3 +149,31 @@ func TestSearchWithoutReplacesMatchesAsBefore(t *testing.T) {
 		t.Errorf("a tool's own name: %+v", hits)
 	}
 }
+
+// A question's filler words do not have to match (every other word still does): the operator's own words
+// find the tool whose description says it in other words; a query of filler alone finds nothing.
+func TestSearchIgnoresFillerWords(t *testing.T) {
+	x := meshToSearch(t)
+	x.Modules["pacman"] = &moduleInfo{Module: "pacman", On: []string{"anchor"}, Tools: []Tool{{Module: "pacman", Name: "pacman_round",
+		Description: "Whether this week's system upgrade ran on every node (the weekly upgrade round, last run of all nodes)."}}}
+	for _, c := range []struct {
+		query string
+		want  string // the first hit's address, "" for none
+	}{
+		{"did our weekly system upgrade run on all our nodes?", "anchor/pacman.pacman_round"},
+		{"the weekly upgrade", "anchor/pacman.pacman_round"},
+		{"did our", ""},
+		{"what is the", ""},
+		{"", ""},
+		{"did our weekly kubernetes upgrade run?", ""},
+	} {
+		hits := x.search(c.query)
+		got := ""
+		if len(hits) > 0 {
+			got = hits[0].Address
+		}
+		if got != c.want || (c.want == "" && len(hits) != 0) {
+			t.Errorf("%q: first hit %q, want %q (%+v)", c.query, got, c.want, hits)
+		}
+	}
+}