issue 1025: mesh-delivery announces each merge on the Approve as the event merged, with its warrant

modules/mesh-delivery/cmd/mesh-delivery/approval_test.go

@@ -251,3 +251,73 @@ func TestAPushToAnUnmarkedGroupMemberEndsTheGroupsAskAndApprove(t *testing.T) {
 		t.Fatalf("merged on an Approve of heads the group no longer has: %v", w.forge.merges)
 	}
 }
+
+// mergedSaid is the module events `merged` the world has said.
+func mergedSaid(w *world) []map[string]any {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	var out []map[string]any
+	for _, m := range w.said {
+		if m["event-kind"] == "merged" {
+			out = append(out, m)
+		}
+	}
+	return out
+}
+
+// Issue 1025: a merge on the operator's Approve is announced once, with the warrant's ask, option and heads.
+func TestIssue1025AMergeOnTheApproveIsAnnouncedWithItsWarrant(t *testing.T) {
+	w := markedGreen(t)
+	id := IDOf("novox/app", readyHead)
+	open := w.op.open()
+	if len(open) != 1 {
+		t.Fatalf("asks %v", open)
+	}
+	if got := mergedSaid(w); len(got) != 0 {
+		t.Fatalf("announced before the merge: %v", got)
+	}
+	d := w.delivery(id)
+	wantHeads := map[string]string{}
+	for k, v := range d.Ready.Heads {
+		wantHeads[k] = v
+	}
+	w.op.answer(open[0], OptionApprove)
+	w.settleAll()
+	got := mergedSaid(w)
+	if len(got) != 1 {
+		t.Fatalf("announced %d times; wanted once: %v", len(got), got)
+	}
+	m := got[0]
+	if m["owner"] != "novox" || m["repo"] != "app" || m["number"] != float64(7) || m["head_sha"] != readyHead ||
+		m["ask_id"] != open[0] || m["option"] != OptionApprove {
+		t.Fatalf("the event does not name the pull request and its warrant: %v", m)
+	}
+	hs, _ := m["heads"].(map[string]any)
+	if len(hs) == 0 || len(hs) != len(wantHeads) {
+		t.Fatalf("heads %v; wanted %v", hs, wantHeads)
+	}
+	for k, v := range wantHeads {
+		if hs[k] != v {
+			t.Fatalf("heads %v; wanted %v", hs, wantHeads)
+		}
+	}
+	if g, ok := m["group"]; ok && g != "" {
+		t.Fatalf("a lone delivery names group %v", g)
+	}
+	w.later(2 * time.Minute)
+	w.settleAll()
+	if n := len(mergedSaid(w)); n != 1 {
+		t.Fatalf("announced %d times after more ticks", n)
+	}
+}
+
+// Issue 1025: a declined merge announces nothing.
+func TestIssue1025ADeclinedMergeAnnouncesNothing(t *testing.T) {
+	w := markedGreen(t)
+	open := w.op.open()
+	w.op.answer(open[0], OptionDecline)
+	w.settleAll()
+	if got := mergedSaid(w); len(got) != 0 || len(w.forge.merges) != 0 {
+		t.Fatalf("declined, yet merges %v, announced %v", w.forge.merges, got)
+	}
+}

modules/mesh-delivery/cmd/mesh-delivery/manifest_test.go

@@ -54,7 +54,7 @@ func TestItClaimsTheDeliverySeatAndFollowsWhatItHandles(t *testing.T) {
 	if !reflect.DeepEqual(m.Consumes, followed) {
 		t.Fatalf("consumes %v, follows %v", m.Consumes, followed)
 	}
-	if !reflect.DeepEqual(m.Emits, []string{"transition", "group"}) {
+	if !reflect.DeepEqual(m.Emits, []string{"transition", "group", "merged"}) {
 		t.Fatalf("emits %v", m.Emits)
 	}
 	if !reflect.DeepEqual(m.State, []string{"deliveries", "groups", "asked", "pulls"}) {

modules/mesh-delivery/cmd/mesh-delivery/ready.go

@@ -343,7 +343,15 @@ func (h *Holder) askMerge(id string, p OpenPull, head string) func() {
 	return func() {
 		err := h.Forge.Merge(p.Owner, p.Repo, p.Number, head)
 		h.mu.Lock()
-		defer h.mu.Unlock()
+		var announce map[string]any // issue 1025: said after unlocking
+		defer func() {
+			h.mu.Unlock()
+			if announce != nil {
+				if e := h.Emit("merged", announce); e != nil {
+					h.Logf("[mesh-delivery] could not announce the merge of %s: %v", id, e)
+				}
+			}
+		}()
 		d := h.deliveries[id]
 		if d == nil || d.Ready == nil {
 			return
@@ -351,6 +359,7 @@ func (h *Holder) askMerge(id string, p OpenPull, head string) func() {
 		r, now := d.Ready, h.Now()
 		r.merging = false
 		if err == nil {
+			announce = mergedEvent(d, p, head)
 			r.Merged, r.Answer, r.RefusedSince = &now, "merged", nil
 			h.Logf("[mesh-delivery] %s merged on its ready mark at %s, its check passed against its trunk's head", id,
 				shortOf(head, 12))
@@ -467,3 +476,20 @@ func (h *Holder) readyLines(now time.Time) []StalledLine {
 	}
 	return out
 }
+
+// mergedEvent is the module event `merged` (issue 1025): the pull request merged, its head and group, and the ask,
+// option and heads the operator's Approve was bound to (the warrant the controller reads back from the router). A merge
+// without an Approve names no ask and no option: no warrant is invented. Under the lock, before anything clears them.
+func mergedEvent(d *Delivery, p OpenPull, head string) map[string]any {
+	r := d.Ready
+	heads := map[string]string{}
+	for k, v := range r.Heads {
+		heads[k] = v
+	}
+	ev := map[string]any{"owner": p.Owner, "repo": p.Repo, "number": p.Number, "head_sha": head, "group": d.Group,
+		"ask_id": "", "option": "", "heads": heads}
+	if r.Approved != nil {
+		ev["ask_id"], ev["option"] = r.AskID, OptionApprove
+	}
+	return ev
+}

modules/mesh-delivery/module.json

@@ -37,7 +37,8 @@
   ],
   "emits": [
     "transition",
-    "group"
+    "group",
+    "merged"
   ],
   "invokes": [
     "seat:mesh-controller.delivery-plan",