Help: show it in the channel when the DM can't be sent, and log where the command came from

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

internal/commands/help/help_test.go

@@ -1,6 +1,9 @@
 package help
 
 import (
+	"io"
+	"net/http"
+	"strings"
 	"testing"
 	"unicode/utf8"
 
@@ -38,3 +41,75 @@ func TestHelpFitsDiscordsLimits(t *testing.T) {
 		t.Errorf("%d fields shown of %d", seen, len(fields()))
 	}
 }
+
+// fakeDiscord answers the calls /help makes and records what the member was
+// shown. dm decides whether the direct message works.
+type fakeDiscord struct {
+	dm        bool
+	edited    []byte
+	callbacks int
+	sent      int
+}
+
+func (f *fakeDiscord) RoundTrip(r *http.Request) (*http.Response, error) {
+	reply := func(code int, body string) (*http.Response, error) {
+		return &http.Response{StatusCode: code, Body: io.NopCloser(strings.NewReader(body)), Header: http.Header{"Content-Type": {"application/json"}}, Request: r}, nil
+	}
+	switch {
+	case strings.HasSuffix(r.URL.Path, "/callback"):
+		f.callbacks++
+		return reply(204, "")
+	case strings.HasSuffix(r.URL.Path, "/users/@me/channels"):
+		if !f.dm {
+			return reply(403, `{"message":"Cannot send messages to this user","code":50007}`)
+		}
+		return reply(200, `{"id":"900","type":1}`)
+	case strings.Contains(r.URL.Path, "/channels/900/messages"):
+		f.sent++
+		return reply(200, `{"id":"1"}`)
+	case strings.Contains(r.URL.Path, "/messages/@original"):
+		f.edited, _ = io.ReadAll(r.Body)
+		return reply(200, `{"id":"2"}`)
+	}
+	return reply(404, `{"message":"unexpected `+r.URL.Path+`"}`)
+}
+
+func run(t *testing.T, f *fakeDiscord, guild string) {
+	t.Helper()
+	s, err := discordgo.New("Bot x")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s.Client = &http.Client{Transport: f}
+	s.MaxRestRetries = 0
+	i := &discordgo.InteractionCreate{Interaction: &discordgo.Interaction{
+		ID: "1", Token: "tok", AppID: "100", GuildID: guild,
+		Member: &discordgo.Member{User: &discordgo.User{ID: "42"}},
+	}}
+	HelpHandler(s, i)
+}
+
+func TestHelpGoesToDMs(t *testing.T) {
+	f := &fakeDiscord{dm: true}
+	run(t, f, "5")
+	if f.sent == 0 || !strings.Contains(string(f.edited), "Check your DMs") || strings.Contains(string(f.edited), `"embeds"`) {
+		t.Errorf("sent=%d edited=%s", f.sent, f.edited)
+	}
+}
+
+func TestHelpFallsBackToTheChannelWhenDMsAreOff(t *testing.T) {
+	f := &fakeDiscord{dm: false}
+	run(t, f, "5")
+	got := string(f.edited)
+	if f.sent != 0 || !strings.Contains(got, "couldn't DM you") || !strings.Contains(got, `"embeds"`) || !strings.Contains(got, "Velox Bot Help") {
+		t.Errorf("the help should be shown in the reply: sent=%d edited=%s", f.sent, got)
+	}
+}
+
+func TestHelpInADMIsShownDirectly(t *testing.T) {
+	f := &fakeDiscord{dm: true}
+	run(t, f, "")
+	if f.callbacks != 1 || f.sent != 0 || f.edited != nil {
+		t.Errorf("one direct answer, no DM: %+v", f)
+	}
+}