Merge pull request 'messenger: read a condition's message before it is sent (issue 422)' (#192) from fix/422-a-condition-message-read-before-it-is-sent into main

modules/messenger/README.md

@@ -183,6 +183,7 @@ ends takes them away everywhere; its expiry is said with its day when it is not
 | `messenger_status` | whether the operator can be reached and why not, per channel kind |
 | `messenger_recent` | the recent sends, edits, digests, answers and failures |
 | `messenger_test` | a test message now, to one kind or every one |
+| `messenger_preview` | what a condition's message would say, tracking line and all, without sending it: the words a send would carry, reduced where the content rule refuses its own |
 | `messenger_check` | whether some words may leave the mesh |
 | `messenger_identities` | the accounts linked as the operator, and from when each approves |
 | `messenger_unlink` | unlink a kind's account, said on every channel |

modules/messenger/cmd/messenger/holder.go

@@ -874,19 +874,9 @@ func (h *Holder) askLines(rec *AskRecord) []string {
 // until what remains may leave. The refusal is recorded and stated once per record.
 func (h *Holder) words(r *Record, what string) Message {
 	now := h.Now()
-	if r.Refused != "" {
-		// Refused before: its words stay withheld in every later message too.
-		for w := 1; w <= 3; w++ {
-			m := h.composeTracked(r, what, now, w)
-			if _, ok := Check(m.Text()); ok {
-				return m
-			}
-		}
-	}
-	m := h.composeTracked(r, what, now, 0)
-	refusal, ok := Check(m.Text())
-	if ok {
-		return m
+	said, _, refusal, ok := h.allowedWords(r, what, now)
+	if ok || r.Refused != "" {
+		return said
 	}
 	h.mu.Lock()
 	r.Refused = refusal.What
@@ -907,26 +897,56 @@ func (h *Holder) words(r *Record, what string) Message {
 			h.Logf("[messenger] could not state the refusal on the bus: %v", err)
 		}
 	}
-	for w := 1; w <= 3; w++ {
-		m := h.composeTracked(r, what, now, w)
-		if _, ok := Check(m.Text()); ok {
-			return m
-		}
-	}
-	return withheld(refusal.What, r.Severity == Urgent)
+	return said
 }
 
 // composeTracked is compose with the line on the issues that track the condition (tracking.go), so the content
 // rule judges the message as it is sent.
-func (h *Holder) composeTracked(r *Record, what string, now time.Time, withhold int) Message {
+func (h *Holder) composeTracked(r *Record, what string, now time.Time, withhold int) (Message, string) {
 	m := compose(r, what, now, h.zone(), withhold)
 	if !h.tracksAsked() || withhold >= 2 {
-		return m
+		return m, ""
 	}
 	issues, known := h.trackedBy(r.Key)
 	return withTracking(m, r, what, issues, known, now, h.zone())
 }
 
+// allowedWords is the message the content rule leaves of a record: its own words when they may leave the
+// mesh, else the same message composed again with less of it until what remains may, else the withheld
+// one. It answers the tracking line it carries, what its own words carried, and whether those words are
+// what it says. **It changes nothing**: `words` is this walk with the refusal recorded and stated once,
+// and `Preview` (preview.go) is this walk alone, so a read of a wording cannot alter what a send says.
+func (h *Holder) allowedWords(r *Record, what string, now time.Time) (Message, string, Refusal, bool) {
+	if r.Refused != "" {
+		// Refused before: its words stay withheld in every later message too.
+		for w := 1; w <= 3; w++ {
+			if m, line := h.composeTracked(r, what, now, w); allowed(m) {
+				return m, line, Refusal{What: r.Refused}, false
+			}
+		}
+	}
+	m, line := h.composeTracked(r, what, now, 0)
+	refusal, ok := Check(m.Text())
+	if ok {
+		return m, line, Refusal{}, true
+	}
+	// Composed from a copy carrying the reason, because a withheld message says what it carried.
+	reduced := *r
+	reduced.Refused = refusal.What
+	for w := 1; w <= 3; w++ {
+		if m, line := h.composeTracked(&reduced, what, now, w); allowed(m) {
+			return m, line, refusal, false
+		}
+	}
+	return withheld(refusal.What, r.Severity == Urgent), "", refusal, false
+}
+
+// allowed says whether a message's words may leave the mesh.
+func allowed(m Message) bool {
+	_, ok := Check(m.Text())
+	return ok
+}
+
 // deliver sends a record's message where its severity routes it.
 
 func (h *Holder) channels() []Channel {

modules/messenger/cmd/messenger/holder_test.go

@@ -66,6 +66,8 @@ func (f *fakeChannel) Edit(id string, m Message) error {
 type memStore struct {
 	recs   map[string]Record
 	recent []Sent
+	// puts counts the writes, so a write of bytes identical to what is stored is still seen (issue 422's review).
+	puts int
 }
 
 func (m *memStore) Put(r Record) error {
@@ -73,6 +75,7 @@ func (m *memStore) Put(r Record) error {
 		m.recs = map[string]Record{}
 	}
 	m.recs[r.Key] = r
+	m.puts++
 	return nil
 }
 func (m *memStore) Delete(k string) error { delete(m.recs, k); return nil }

modules/messenger/cmd/messenger/main.go

@@ -603,6 +603,17 @@ func tools(h *Holder, l *listening) []stdio.Tool {
 				"text":    str("the words (default: a line saying it is a test)"),
 			},
 			Run: func(a map[string]any) (any, error) { return h.Test(strArg(a, "channel"), strArg(a, "text")), nil }},
+		{Name: "messenger_preview",
+			Description: "What a condition's message would say, without sending it: the title, the words, the " +
+				"line on the issues that track it, and whether the content rule would let them leave the mesh — " +
+				"where they may not, the reduced message a send would carry instead. Composed for a condition this " +
+				"router holds open, by the walk a send composes with; a clearing as if it cleared now, a silence " +
+				"only while there is one. It sends, queues and records nothing.",
+			Input: map[string]any{
+				"key":  str("the condition's key, as the controller names it, e.g. module.openrazer.laptop.relogin-needed"),
+				"what": str("which message about it: raised (default), reminder, quiet-reminder, escalated, reopened, cleared, silenced"),
+			},
+			Run: func(a map[string]any) (any, error) { return h.Preview(strArg(a, "key"), strArg(a, "what")) }},
 		{Name: "messenger_check",
 			Description: "Would these words be allowed to leave the mesh? Runs the content rule — no address, path or " +
 				"secret — and answers allowed, or the class of what it carried. Sends nothing.",

modules/messenger/cmd/messenger/preview.go

@@ -0,0 +1,137 @@
+package main
+
+// What a condition's message would say, read before it is sent (novox/hq issue 422). The words a
+// condition reaches the operator with are composed here, in this router, from the condition's own plain
+// words and the line on the issues that track it (tracking.go). Until this tool, the only way to read
+// them was to wait for a send and look at the operator's screen: the channels keep the text of nothing
+// they sent (`Sent` holds a key and an outcome, never words), and a notification still on the desk is
+// not in the notifier's history. So a wording could not be proven without nagging the operator.
+//
+// It is the sending path's own walk and nothing beside it: `allowedWords` (holder.go), which composes
+// the message, carries the tracking line into it and reduces it where the content rule refuses its
+// words — the same function `words` calls for a send, so a preview cannot drift from one. It records no
+// refusal, states nothing on the bus, queues nothing, sends nothing and changes no record: the walk runs
+// against a copy.
+//
+// What it does not say, because a channel adds it where a condition carries an open ask (`sayOn`): who
+// asks, what each answer does, and the answers themselves. A preview of such a condition says that its
+// message carries more, rather than letting the words read as the whole of it.
+//
+// Two messages are about a moment that has not come. A clearing is composed as if the condition cleared
+// now, which the answer says, because a clearing composed from an open record would say "after a moment"
+// for a condition open four hours. A silence is refused unless the condition is under one: a silence
+// message says until when, and a condition nobody silenced has no such moment to say.
+
+import (
+	"sort"
+	"strings"
+)
+
+// The messages a condition is said with, as `what` names them through the sending path (holder.go).
+var previewable = []string{"raised", "reminder", "quiet-reminder", "escalated", "reopened", "cleared", "silenced"}
+
+// Preview is the message for a condition this router holds, composed as it would be sent, and sent
+// nowhere. `what` is which of the messages about it (previewable, default `raised`).
+func (h *Holder) Preview(key, what string) (map[string]any, error) {
+	key = strings.TrimSpace(key)
+	if key == "" {
+		return nil, errorf("key is required: the condition's key, as the controller names it — `mesh-controller.conditions` says which are open")
+	}
+	what = strings.TrimSpace(what)
+	if what == "" {
+		what = "raised"
+	}
+	if !previewableWhat(what) {
+		return nil, errorf("what %q is not one of the messages a condition is said with: %s", what, strings.Join(previewable, ", "))
+	}
+
+	// Asked outside the work, as every tick that composes a message warms it: a preview on a cold
+	// tracking word would say the tracking could not be checked, which is true of this instant and not
+	// of the send it is read for.
+	h.warmTracking()
+
+	now := h.Now()
+	h.mu.Lock()
+	held, holding := h.open[key]
+	var r Record
+	if holding {
+		r = *held // the walk runs against a copy: a preview changes no record this router holds
+	}
+	var conditions []string
+	for k, rec := range h.open {
+		if rec.Origin == "condition" {
+			conditions = append(conditions, k)
+		}
+	}
+	h.mu.Unlock()
+
+	if !holding || r.Origin != "condition" {
+		sort.Strings(conditions)
+		switch {
+		case holding && len(conditions) == 0:
+			return nil, errorf("%s is not a condition but this router's own %s record, which is said as part of an ask, never on its own; it holds no condition",
+				key, r.Origin)
+		case holding:
+			return nil, errorf("%s is not a condition but this router's own %s record, which is said as part of an ask, never on its own; it holds the conditions %s",
+				key, r.Origin, strings.Join(conditions, ", "))
+		case len(conditions) == 0:
+			return nil, errorf("no condition %s is open here, and this router holds none: `mesh-controller.conditions` says what the controller holds open", key)
+		default:
+			return nil, errorf("no condition %s is open here; it holds %s", key, strings.Join(conditions, ", "))
+		}
+	}
+	if what == "silenced" && !r.silenced(now) {
+		return nil, errorf("%s is under no silence, and a silence message says until when it is quiet: there is no such message to read", key)
+	}
+	if what == "cleared" {
+		// As if it cleared now: the clearing says how long it was open, which an open record cannot say.
+		r.Cleared = now
+	}
+
+	asking := h.openAsk(&r) != nil // askOf takes the same lock, so this is asked outside it
+	m, line, refusal, ownWords := h.allowedWords(&r, what, now)
+	if r.Answered != "" {
+		m = h.answeredWords(&r, m)
+	}
+	out := map[string]any{
+		"key":   key,
+		"what":  what,
+		"title": m.Title,
+		"body":  m.Body,
+		"sent":  "nothing: this composes the words and sends nowhere",
+	}
+	if m.Urgent {
+		out["urgent"] = true
+	}
+	if m.Quiet {
+		out["quiet"] = true
+	}
+	if line != "" {
+		out["tracking"] = line
+	}
+	if what == "cleared" {
+		out["as-if"] = "it cleared now: how long it was open is said from this moment"
+	}
+	if asking {
+		out["carries-more"] = "this condition has an open ask, so a channel's message also carries who asks, what each answer does, and the answers themselves"
+	}
+	out["allowed"] = ownWords
+	if !ownWords {
+		// What stands above is what would leave; its own words would not, and this says why.
+		out["carried"] = refusal.What
+		if refusal.Class != "" {
+			out["class"] = refusal.Class
+		}
+		out["instead"] = "its own words may not leave the mesh, so this is the message as reduced for sending"
+	}
+	return out, nil
+}
+
+func previewableWhat(what string) bool {
+	for _, w := range previewable {
+		if w == what {
+			return true
+		}
+	}
+	return false
+}

modules/messenger/cmd/messenger/preview_test.go

@@ -0,0 +1,288 @@
+package main
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+)
+
+// A condition's message can be read before it is sent (novox/hq issue 422): the words a send would
+// carry, the tracking line among them, and nothing of this router moved while they were read.
+
+// previewHolder is a router holding one urgent condition — one a send goes out for at once, so a preview
+// that sends, queues or records anything is caught — with the issues given tracking its key.
+func previewHolder(t *testing.T, issues []TrackedIssue) (*Holder, *fakeChannel, *fakeChannel, *clock, *memStore, Condition) {
+	t.Helper()
+	h, tg, dt, c, st := newHolder(t)
+	h.Tracking = func() (map[string][]TrackedIssue, error) {
+		return map[string][]TrackedIssue{"mesh.hand-acts.rolled-back.healer-wanted": issues}, nil
+	}
+	k := cond("mesh.hand-acts.rolled-back.healer-wanted", Urgent, "rolled-back was repaired by hand 4 times in 14 days")
+	k.Explanation = "Nothing for you to do. A person repaired rolled-back by hand 4 times in 14 days, so an automatic repair is wanted for it. Nothing is broken now."
+	k.Needs = ""
+	k.Raised = c.now()
+	h.Condition(EventRaised, k)
+	settle(h, c)
+	if len(tg.sends) == 0 && len(dt.sends) == 0 {
+		t.Fatal("the condition this is read from was never sent, so a preview sending something would not show")
+	}
+	return h, tg, dt, c, st, k
+}
+
+// unmoved fails when anything a send would move has moved: the sends, the queue, the history, what is
+// stored, and the record itself.
+type unmoved struct {
+	sends, queued, recent, refusals, puts int
+	stored                                Record
+	held                                  Record
+}
+
+func mark(t *testing.T, h *Holder, tg, dt *fakeChannel, st *memStore, key string) unmoved {
+	t.Helper()
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	queued := 0 // the outbox is held per channel, never per condition
+	for _, list := range h.outbox {
+		queued += len(list)
+	}
+	return unmoved{sends: len(tg.sends) + len(dt.sends), queued: queued, recent: len(h.recent),
+		refusals: len(h.refusals), puts: st.puts, stored: st.recs[key], held: *h.open[key]}
+}
+
+func (was unmoved) check(t *testing.T, h *Holder, tg, dt *fakeChannel, st *memStore, c *clock, key string) {
+	t.Helper()
+	// A queued message waits for a tick, so the queue is read and then given one: either would catch it.
+	now := mark(t, h, tg, dt, st, key)
+	if now.sends != was.sends {
+		t.Errorf("a preview sent %d message(s)", now.sends-was.sends)
+	}
+	if now.queued != was.queued {
+		t.Errorf("a preview queued %d message(s)", now.queued-was.queued)
+	}
+	if now.recent != was.recent {
+		t.Errorf("a preview recorded %d send(s)", now.recent-was.recent)
+	}
+	if now.refusals != was.refusals {
+		t.Errorf("a preview recorded %d refusal(s): only a send does that", now.refusals-was.refusals)
+	}
+	if now.puts != was.puts {
+		t.Errorf("a preview wrote to the store %d time(s), even if the bytes were the same", now.puts-was.puts)
+	}
+	if !reflect.DeepEqual(now.stored, was.stored) {
+		t.Errorf("a preview wrote the record: %+v", now.stored)
+	}
+	if !reflect.DeepEqual(now.held, was.held) {
+		t.Errorf("a preview changed the record held: %+v", now.held)
+	}
+	settle(h, c)
+	if after := mark(t, h, tg, dt, st, key); after.sends != was.sends {
+		t.Errorf("a preview queued a message, which the next tick sent: %d", after.sends-was.sends)
+	}
+}
+
+func TestAConditionsMessageIsReadWithoutBeingSent(t *testing.T) {
+	h, tg, dt, c, st, k := previewHolder(t, []TrackedIssue{{Number: 352, Status: "located", Needs: "decision"}})
+	was := mark(t, h, tg, dt, st, k.Key)
+
+	out, err := h.Preview(k.Key, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out["what"] != "raised" {
+		t.Errorf("what %v; a preview with none asked is the first message", out["what"])
+	}
+	if out["title"] != "Urgent: mesh hand-acts rolled-back healer-wanted" {
+		t.Errorf("title %q", out["title"])
+	}
+	body, _ := out["body"].(string)
+	if !strings.Contains(body, "Tracked as issue 352: nobody is working on it; it waits for a decision first.") {
+		t.Errorf("the body says nothing of the issue that tracks it: %q", body)
+	}
+	if out["tracking"] != "Tracked as issue 352: nobody is working on it; it waits for a decision first." {
+		t.Errorf("tracking %q", out["tracking"])
+	}
+	if out["allowed"] != true {
+		t.Errorf("allowed %v, carried %v: these words may leave the mesh", out["allowed"], out["carried"])
+	}
+	// The verdict is left out while nobody works on the issue (ADR 0285 §4), as in a send.
+	if strings.Contains(body, "Nothing for you to do.") {
+		t.Errorf("the preview reassures where nothing is being done: %q", body)
+	}
+	keyless(t, Message{Title: out["title"].(string), Body: body})
+	was.check(t, h, tg, dt, st, c, k.Key)
+}
+
+func TestAPreviewSaysTheWordsTheChannelWasGiven(t *testing.T) {
+	issues := []TrackedIssue{{Number: 386, Status: "fixing", Worker: "fix-386@g14", Since: at(21, 10)}}
+	h, tg, dt, c, st, k := previewHolder(t, issues)
+	sent := dt.sends[len(dt.sends)-1] // the message the desk was actually handed
+	was := mark(t, h, tg, dt, st, k.Key)
+
+	out, err := h.Preview(k.Key, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out["title"] != sent.Title || out["body"] != sent.Body {
+		t.Fatalf("preview %q / %q; the channel was given %q / %q", out["title"], out["body"], sent.Title, sent.Body)
+	}
+	if !strings.Contains(sent.Body, "Tracked as issue 386: fix-386 on g14 is fixing it since ") {
+		t.Fatalf("the message this is compared against carries no tracking line: %q", sent.Body)
+	}
+	was.check(t, h, tg, dt, st, c, k.Key)
+}
+
+func TestAClearingIsPreviewedAsIfItClearedNow(t *testing.T) {
+	h, tg, dt, c, st, k := previewHolder(t, []TrackedIssue{{Number: 352, Status: "located"}})
+	c.pass(4 * time.Hour)
+	was := mark(t, h, tg, dt, st, k.Key)
+
+	out, err := h.Preview(k.Key, "cleared")
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Composed from the open record, this said "after a moment": the clearing's own time is zero, so the
+	// time it was open came out negative.
+	if out["title"] != "Resolved: mesh hand-acts rolled-back healer-wanted, after 4.0 h" {
+		t.Errorf("title %q; a clearing says how long it was open", out["title"])
+	}
+	if out["as-if"] == nil {
+		t.Errorf("the answer does not say the clearing is composed as if it cleared now: %v", out)
+	}
+	if _, said := out["tracking"]; said {
+		t.Errorf("a clearing says a tracking line: %v", out["tracking"])
+	}
+	was.check(t, h, tg, dt, st, c, k.Key)
+}
+
+func TestASilenceIsPreviewedOnlyWhileThereIsOne(t *testing.T) {
+	h, tg, dt, c, st, k := previewHolder(t, []TrackedIssue{{Number: 352, Status: "located"}})
+
+	// Under no silence, a silence message would say a moment that does not exist.
+	_, err := h.Preview(k.Key, "silenced")
+	if err == nil || !strings.Contains(err.Error(), "under no silence") {
+		t.Fatalf("a silence previewed without one: %v", err)
+	}
+
+	h.mu.Lock()
+	h.open[k.Key].SilencedTill = c.now().Add(7 * 24 * time.Hour)
+	h.open[k.Key].SilencedWhy = "the operator knows"
+	h.mu.Unlock()
+	was := mark(t, h, tg, dt, st, k.Key)
+
+	out, err := h.Preview(k.Key, "silenced")
+	if err != nil {
+		t.Fatal(err)
+	}
+	title, _ := out["title"].(string)
+	if !strings.HasPrefix(title, "Silenced until ") || strings.Contains(title, "Jan 1 ") || strings.Contains(title, " 1 Jan ") {
+		t.Errorf("title %q; a silence says until when it is quiet", title)
+	}
+	if _, said := out["tracking"]; said {
+		t.Errorf("a silence says a tracking line: %v", out["tracking"])
+	}
+	was.check(t, h, tg, dt, st, c, k.Key)
+}
+
+func TestAPreviewOfWhatThisRouterDoesNotHoldIsRefusedByName(t *testing.T) {
+	h, _, _, _, _, k := previewHolder(t, nil)
+
+	_, err := h.Preview("machine.ace.silent", "")
+	if err == nil {
+		t.Fatal("a condition this router does not hold was previewed")
+	}
+	if !strings.Contains(err.Error(), "machine.ace.silent") || !strings.Contains(err.Error(), k.Key) {
+		t.Errorf("the refusal says neither what was asked nor what is held: %v", err)
+	}
+
+	if _, err := h.Preview("", ""); err == nil || !strings.Contains(err.Error(), "key is required") {
+		t.Errorf("no key: %v", err)
+	}
+	if _, err := h.Preview(k.Key, "shouted"); err == nil || !strings.Contains(err.Error(), "shouted") {
+		t.Errorf("an unknown message: %v", err)
+	}
+
+	// An ask's own record is held here too, and is said as part of an ask, never as a condition.
+	h.mu.Lock()
+	h.open["ask.someone.1"] = &Record{Key: "ask.someone.1", Origin: "ask", Severity: Urgent, Summary: "a question"}
+	h.mu.Unlock()
+	_, err = h.Preview("ask.someone.1", "")
+	if err == nil || !strings.Contains(err.Error(), "not a condition") || !strings.Contains(err.Error(), k.Key) {
+		t.Errorf("an ask's record previewed as a condition: %v", err)
+	}
+
+	// A router holding an ask and no condition says what that key is, not that it holds nothing.
+	bare, _, _, _, _ := newHolder(t)
+	bare.mu.Lock()
+	bare.open["ask.someone.2"] = &Record{Key: "ask.someone.2", Origin: "ask", Severity: Urgent, Summary: "a question"}
+	bare.mu.Unlock()
+	_, err = bare.Preview("ask.someone.2", "")
+	if err == nil || !strings.Contains(err.Error(), "not a condition") {
+		t.Errorf("the only record held is an ask's: %v", err)
+	}
+}
+
+func TestAPreviewAsksTheTrackerWhenItsWordWentCold(t *testing.T) {
+	asked := 0
+	h, _, _, c, _, k := previewHolder(t, []TrackedIssue{{Number: 352, Status: "located"}})
+	h.Tracking = func() (map[string][]TrackedIssue, error) {
+		asked++
+		return map[string][]TrackedIssue{k.Key: {{Number: 352, Status: "located"}}}, nil
+	}
+
+	c.pass(TrackingKept + time.Minute) // older than an answer is used for
+	out, err := h.Preview(k.Key, "quiet-reminder")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if asked != 1 {
+		t.Fatalf("the tracker was asked %d times; a preview on a cold word asks once", asked)
+	}
+	if out["tracking"] != "Tracked as issue 352: nobody is working on it." {
+		t.Errorf("tracking %q; a preview that asked should say what it heard", out["tracking"])
+	}
+}
+
+func TestAPreviewSaysTheReducedWordsAndWhyWhenItsOwnMayNotLeave(t *testing.T) {
+	h, tg, dt, c, st, _ := previewHolder(t, nil)
+	stated := 0
+	h.Emit = func(string, any) error { stated++; return nil }
+	// A warning that needs nothing is held, not sent, so this refusal is one no send has met yet.
+	k := cond("machine.ace.unreadable", Warning, "a file on it could not be read")
+	k.Explanation = "Nothing for you to do. A file at /home/someone/secrets.txt could not be read."
+	k.Needs = ""
+	k.Raised = c.now()
+	h.Condition(EventRaised, k)
+	settle(h, c)
+	was := mark(t, h, tg, dt, st, k.Key)
+
+	out, err := h.Preview(k.Key, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out["allowed"] != false || out["carried"] == nil {
+		t.Fatalf("allowed %v, carried %v; the content rule refuses a path", out["allowed"], out["carried"])
+	}
+	// The words said are the ones that would go out, not the refused ones.
+	body, _ := out["body"].(string)
+	if strings.Contains(body, "/home/") {
+		t.Errorf("the preview says words no send would carry: %q", body)
+	}
+	if !strings.Contains(body, "withheld") {
+		t.Errorf("body %q; a reduced message says that part of it was withheld", body)
+	}
+	if !strings.Contains(body, "a file path") {
+		t.Errorf("body %q; a reduced message says what it carried", body)
+	}
+	if out["instead"] == nil {
+		t.Errorf("the answer does not say these are the reduced words: %v", out)
+	}
+	// Reading it recorded no refusal, stated nothing on the bus, and left the record's own words alone.
+	if stated != 0 {
+		t.Errorf("a preview stated %d fact(s) on the bus", stated)
+	}
+	if was.held.Refused != "" {
+		t.Fatalf("the record was already refused before the preview: %q", was.held.Refused)
+	}
+	was.check(t, h, tg, dt, st, c, k.Key)
+}

modules/messenger/cmd/messenger/tracking.go

@@ -159,9 +159,11 @@ const (
 // withTracking is a condition's message with the line on the issues that track it, and its verdict changed where
 // an issue waits for the operator or nobody works on any of them. Cleared and silenced messages, and one withheld
 // whole, say nothing of it.
-func withTracking(m Message, r *Record, what string, issues []TrackedIssue, known bool, now time.Time, loc *time.Location) Message {
+// It answers the line it put in the message, empty when the message carries none, so whoever composed it
+// never has to work out the rule a second time (novox/hq issue 422).
+func withTracking(m Message, r *Record, what string, issues []TrackedIssue, known bool, now time.Time, loc *time.Location) (Message, string) {
 	if r.Origin != "condition" || what == "cleared" || what == "silenced" || m.Title == "A mesh message was withheld" {
-		return m
+		return m, ""
 	}
 	line, verdict := trackingWords(issues, known, now, loc)
 	// since is the last line, which never holds a line break; the explanation is everything before it.
@@ -184,7 +186,7 @@ func withTracking(m Message, r *Record, what string, issues []TrackedIssue, know
 		}
 	}
 	m.Body = strings.Join(parts, "\n")
-	return m
+	return m, line
 }
 
 // needsAnswer is the "Needs you:" sentence for the issues that wait for the operator's answer.

modules/messenger/cmd/messenger/tracking_test.go

@@ -26,7 +26,8 @@ func trackedMessage(issues []TrackedIssue, known bool) Message {
 		Explanation: "Nothing for you to do. A person repaired rolled-back by hand 4 times in 14 days, so an automatic repair is wanted for it. Nothing is broken now.",
 		Raised:      trackNow.Add(-26 * time.Hour)}
 	m := compose(r, "quiet-reminder", trackNow, time.UTC, 0)
-	return withTracking(m, r, "quiet-reminder", issues, known, trackNow, time.UTC)
+	out, _ := withTracking(m, r, "quiet-reminder", issues, known, trackNow, time.UTC)
+	return out
 }
 
 func TestAConditionsMessageSaysWhereTheIssueThatTracksItStands(t *testing.T) {
@@ -129,7 +130,7 @@ func TestNothingForYouToDoIsNeverSaidWhileTheIssueWaitsOnTheOperatorOrNobodyWork
 func TestAVerdictThatNeedsTheOperatorStands(t *testing.T) {
 	r := &Record{Key: "module.mounts.shanks.unhealthy", Origin: "condition", Severity: Urgent, Headline: "mounts not working on shanks",
 		Explanation: "Needs you: give the share's login. mounts on shanks is not healthy.", Raised: trackNow.Add(-time.Hour)}
-	m := withTracking(compose(r, "raised", trackNow, time.UTC, 0), r, "raised",
+	m, _ := withTracking(compose(r, "raised", trackNow, time.UTC, 0), r, "raised",
 		[]TrackedIssue{{Number: 386, Status: "open", Needs: "operator"}}, true, trackNow, time.UTC)
 	want := "Needs you: give the share's login. mounts on shanks is not healthy.\nTracked as issue 386: it waits for your answer.\nSince 18:30."
 	if m.Body != want {
@@ -144,14 +145,16 @@ func TestAClearingASilenceAndANoticeSayNoIssue(t *testing.T) {
 		Cleared: trackNow, SilencedTill: trackNow.Add(time.Hour)}
 	for _, what := range []string{"cleared", "silenced"} {
 		m := compose(r, what, trackNow, time.UTC, 0)
-		if got := withTracking(m, r, what, issues, true, trackNow, time.UTC); got.Body != m.Body {
-			t.Errorf("%s: %q", what, got.Body)
+		got, line := withTracking(m, r, what, issues, true, trackNow, time.UTC)
+		if got.Body != m.Body || line != "" {
+			t.Errorf("%s: %q, line %q", what, got.Body, line)
 		}
 	}
 	n := &Record{Key: "n", Origin: "notify", Headline: "a notice", Raised: trackNow}
 	m := compose(n, "raised", trackNow, time.UTC, 0)
-	if got := withTracking(m, n, "raised", issues, true, trackNow, time.UTC); got.Body != m.Body {
-		t.Errorf("notice: %q", got.Body)
+	got, line := withTracking(m, n, "raised", issues, true, trackNow, time.UTC)
+	if got.Body != m.Body || line != "" {
+		t.Errorf("notice: %q, line %q", got.Body, line)
 	}
 }
 

modules/messenger/module.json

@@ -103,6 +103,7 @@
     "messenger_status",
     "messenger_recent",
     "messenger_test",
+    "messenger_preview",
     "messenger_check",
     "messenger_identities",
     "messenger_unlink"