fix: stop styled lines from indenting the text that follows

An incident with nobody assigned and nobody holding it rendered its
detail view like this:

    Assigned:   nobody
                        Acked:      not acknowledged

lipgloss pads every line of a styled block out to the width of its widest
line. A trailing newline inside Render therefore produces a second line
made entirely of padding, and the next write to the builder starts after
that padding instead of at the left margin. Twelve call sites put the
newline inside.

Adding a line() helper that keeps the newline outside, and using it
throughout the content builders.

Shipped in v0.4.0 and only visible on the unassigned or unacknowledged
path, which is why it survived the pre-release check: that run had
somebody on call, so the incident was assigned and acknowledged and both
lines took the styled-with-value branch instead.

view_test.go covers the content builders, including the two states that
were broken and an expired snooze not being reported as a snooze.

.github/workflows/release.yml

@@ -6,7 +6,26 @@ on:
       - 'v*'
 
 jobs:
+  # Gates the build, so a tag that fails here publishes no binaries. The suite
+  # covers the API client against a stub server, the Update state machine, and
+  # View rendering — all three are pure enough to test without a terminal.
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Test
+        run: go test ./...
+
   build:
+    needs: test
     runs-on: ubuntu-latest
     strategy:
       matrix:

internal/api/client_test.go

@@ -0,0 +1,304 @@
+package api
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+// call records what the client actually put on the wire. The paths and methods
+// are the contract with terdut-server, and getting one wrong is exactly how this
+// client broke when the server split alerts from incidents.
+type call struct {
+	method string
+	path   string
+	query  string
+	body   string
+	auth   string
+}
+
+// stub serves one canned response and records the request that fetched it.
+func stub(t *testing.T, status int, response string) (*Client, *call) {
+	t.Helper()
+	got := &call{}
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, _ := io.ReadAll(r.Body)
+		got.method, got.path, got.query = r.Method, r.URL.Path, r.URL.RawQuery
+		got.body, got.auth = string(body), r.Header.Get("Authorization")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(status)
+		io.WriteString(w, response)
+	}))
+	t.Cleanup(srv.Close)
+	return NewClient(srv.URL, "test-key"), got
+}
+
+func TestClient_SendsBearerToken(t *testing.T) {
+	c, got := stub(t, http.StatusOK, `[]`)
+	if _, err := c.ListIncidents("", false, false, 0); err != nil {
+		t.Fatalf("list: %v", err)
+	}
+	if got.auth != "Bearer test-key" {
+		t.Errorf("expected bearer token, got %q", got.auth)
+	}
+}
+
+// Every incident action, with the method and path terdut-server exposes.
+func TestClient_IncidentEndpoints(t *testing.T) {
+	tests := []struct {
+		name   string
+		invoke func(*Client) error
+		method string
+		path   string
+		// resp defaults to a JSON object; endpoints returning a list need an array.
+		resp string
+	}{
+		{"get", func(c *Client) error { _, err := c.GetIncident(7); return err },
+			http.MethodGet, "/api/incidents/7", ""},
+		{"timeline", func(c *Client) error { _, err := c.GetIncidentTimeline(7); return err },
+			http.MethodGet, "/api/incidents/7/timeline", `[]`},
+		{"acknowledge", func(c *Client) error { _, err := c.AcknowledgeIncident(7); return err },
+			http.MethodPost, "/api/incidents/7/acknowledge", ""},
+		{"unacknowledge", func(c *Client) error { return c.UnacknowledgeIncident(7) },
+			http.MethodDelete, "/api/incidents/7/acknowledge", ""},
+		{"resolve", func(c *Client) error { _, err := c.ResolveIncident(7); return err },
+			http.MethodPost, "/api/incidents/7/resolve", ""},
+		{"assign", func(c *Client) error { _, err := c.AssignIncident(7, 3); return err },
+			http.MethodPost, "/api/incidents/7/assign", ""},
+		{"snooze", func(c *Client) error { _, err := c.SnoozeIncident(7, "2h"); return err },
+			http.MethodPost, "/api/incidents/7/snooze", ""},
+		{"unsnooze", func(c *Client) error { return c.UnsnoozeIncident(7) },
+			http.MethodDelete, "/api/incidents/7/snooze", ""},
+		{"archive", func(c *Client) error { _, err := c.ArchiveIncident(7); return err },
+			http.MethodPost, "/api/incidents/7/archive", ""},
+		{"unarchive", func(c *Client) error { return c.UnarchiveIncident(7) },
+			http.MethodDelete, "/api/incidents/7/archive", ""},
+		{"add note", func(c *Client) error { _, err := c.AddNote(7, "hi"); return err },
+			http.MethodPost, "/api/incidents/7/notes", ""},
+		{"delete note", func(c *Client) error { return c.DeleteNote(7, 12) },
+			http.MethodDelete, "/api/incidents/7/notes/12", ""},
+		{"stats", func(c *Client) error { _, err := c.GetIncidentStats(); return err },
+			http.MethodGet, "/api/stats/incidents", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resp := tt.resp
+			if resp == "" {
+				resp = `{}`
+			}
+			c, got := stub(t, http.StatusOK, resp)
+			if err := tt.invoke(c); err != nil {
+				t.Fatalf("%s: %v", tt.name, err)
+			}
+			if got.method != tt.method || got.path != tt.path {
+				t.Errorf("expected %s %s, got %s %s", tt.method, tt.path, got.method, got.path)
+			}
+		})
+	}
+}
+
+func TestListIncidents_Filters(t *testing.T) {
+	tests := []struct {
+		name     string
+		status   string
+		archived bool
+		snoozed  bool
+		limit    int
+		want     string
+	}{
+		{"default is the open queue", "", false, false, 0, ""},
+		{"status", "triggered", false, false, 0, "status=triggered"},
+		{"archived", "resolved", true, false, 0, "archived=true&status=resolved"},
+		{"snoozed", "", false, true, 0, "snoozed=true"},
+		{"limit", "", false, false, 500, "limit=500"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c, got := stub(t, http.StatusOK, `[]`)
+			if _, err := c.ListIncidents(tt.status, tt.archived, tt.snoozed, tt.limit); err != nil {
+				t.Fatalf("list: %v", err)
+			}
+			if got.query != tt.want {
+				t.Errorf("expected query %q, got %q", tt.want, got.query)
+			}
+		})
+	}
+}
+
+func TestClient_RequestBodies(t *testing.T) {
+	t.Run("assign", func(t *testing.T) {
+		c, got := stub(t, http.StatusOK, `{}`)
+		if _, err := c.AssignIncident(1, 42); err != nil {
+			t.Fatalf("assign: %v", err)
+		}
+		var body struct {
+			UserID int64 `json:"user_id"`
+		}
+		if err := json.Unmarshal([]byte(got.body), &body); err != nil {
+			t.Fatalf("decode body %q: %v", got.body, err)
+		}
+		if body.UserID != 42 {
+			t.Errorf("expected user_id 42, got %d", body.UserID)
+		}
+	})
+
+	t.Run("snooze", func(t *testing.T) {
+		c, got := stub(t, http.StatusOK, `{}`)
+		if _, err := c.SnoozeIncident(1, "90m"); err != nil {
+			t.Fatalf("snooze: %v", err)
+		}
+		var body struct {
+			Duration string `json:"duration"`
+		}
+		if err := json.Unmarshal([]byte(got.body), &body); err != nil {
+			t.Fatalf("decode body %q: %v", got.body, err)
+		}
+		if body.Duration != "90m" {
+			t.Errorf("expected duration 90m, got %q", body.Duration)
+		}
+	})
+}
+
+// The 409 on re-resolving is the server telling the user why nothing happened,
+// so the message has to survive into the error the TUI displays.
+func TestClient_SurfacesServerErrorMessage(t *testing.T) {
+	c, _ := stub(t, http.StatusConflict, `{"error":"incident is resolved"}`)
+	_, err := c.ResolveIncident(1)
+	if err == nil {
+		t.Fatal("expected an error on 409")
+	}
+	if !strings.Contains(err.Error(), "incident is resolved") || !strings.Contains(err.Error(), "409") {
+		t.Errorf("expected status and server message in %q", err.Error())
+	}
+}
+
+func TestClient_ErrorWithoutBody(t *testing.T) {
+	c, _ := stub(t, http.StatusInternalServerError, ``)
+	if _, err := c.GetIncident(1); err == nil || !strings.Contains(err.Error(), "500") {
+		t.Errorf("expected a 500 error, got %v", err)
+	}
+}
+
+// Nobody on call is a normal state, not a failure.
+func TestGetCurrentOnCall_404IsNotAnError(t *testing.T) {
+	c, _ := stub(t, http.StatusNotFound, `{"error":"no one is on call today"}`)
+	entry, err := c.GetCurrentOnCall()
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if entry != nil {
+		t.Errorf("expected nil entry, got %+v", entry)
+	}
+}
+
+// Optional fields are omitted by the server rather than sent null, so decoding
+// has to leave them zero instead of failing.
+func TestIncident_DecodesSparseServerShape(t *testing.T) {
+	c, _ := stub(t, http.StatusOK, `{
+		"id": 1,
+		"group_key": "{}:{alertname=\"DiskFull\"}",
+		"title": "DiskFull (namespace=prod)",
+		"group_labels": {"alertname": "DiskFull", "namespace": "prod"},
+		"status": "triggered",
+		"severity": "critical",
+		"triggered_at": "2026-07-30T10:00:00Z"
+	}`)
+
+	inc, err := c.GetIncident(1)
+	if err != nil {
+		t.Fatalf("get: %v", err)
+	}
+	if inc.Title != "DiskFull (namespace=prod)" || inc.Severity != "critical" {
+		t.Errorf("unexpected incident %+v", inc)
+	}
+	if inc.GroupLabels["namespace"] != "prod" {
+		t.Errorf("expected group labels decoded, got %v", inc.GroupLabels)
+	}
+	if !inc.IsOpen() {
+		t.Error("an incident with no resolved_at is open")
+	}
+	if inc.IsSnoozed() {
+		t.Error("an incident with no snoozed_until is not snoozed")
+	}
+	if inc.AcknowledgedByID != nil || inc.AssignedToID != nil {
+		t.Error("expected acknowledgement and assignment to be absent")
+	}
+}
+
+// A snooze expires by falling into the past; the server sweeps nothing, so the
+// client is what decides a stale snooze no longer counts.
+func TestIncident_IsSnoozed(t *testing.T) {
+	past := time.Now().Add(-time.Hour)
+	future := time.Now().Add(time.Hour)
+
+	tests := []struct {
+		name  string
+		until *time.Time
+		want  bool
+	}{
+		{"never snoozed", nil, false},
+		{"snooze in the past has expired", &past, false},
+		{"snooze in the future holds", &future, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := (Incident{SnoozedUntil: tt.until}).IsSnoozed(); got != tt.want {
+				t.Errorf("expected %v, got %v", tt.want, got)
+			}
+		})
+	}
+}
+
+func TestIncident_IsOpen(t *testing.T) {
+	now := time.Now()
+	if !(Incident{}).IsOpen() {
+		t.Error("no resolved_at means open")
+	}
+	if (Incident{ResolvedAt: &now}).IsOpen() {
+		t.Error("resolved_at means closed")
+	}
+}
+
+func TestAlert_DecodesIncidentLink(t *testing.T) {
+	c, _ := stub(t, http.StatusOK, `{"id":3,"name":"DiskFull","status":"firing","incident_id":7}`)
+	a, err := c.GetAlert(3)
+	if err != nil {
+		t.Fatalf("get alert: %v", err)
+	}
+	if a.IncidentID == nil || *a.IncidentID != 7 {
+		t.Errorf("expected incident_id 7, got %v", a.IncidentID)
+	}
+}
+
+func TestListAlerts_ArchivedFilter(t *testing.T) {
+	c, got := stub(t, http.StatusOK, `[]`)
+	if _, err := c.ListAlerts("", true, 50); err != nil {
+		t.Fatalf("list alerts: %v", err)
+	}
+	if got.path != "/api/alerts" || got.query != "archived=true&limit=50" {
+		t.Errorf("unexpected request %s?%s", got.path, got.query)
+	}
+}
+
+// MTTA and MTTR are null until something has been acknowledged or resolved. That
+// is "no data", and it must not decode to a confident zero.
+func TestIncidentStats_NullAveragesStayNil(t *testing.T) {
+	c, _ := stub(t, http.StatusOK,
+		`{"total":2,"triggered":2,"acknowledged":0,"resolved":0,"mtta_seconds":null,"mttr_seconds":null}`)
+	stats, err := c.GetIncidentStats()
+	if err != nil {
+		t.Fatalf("stats: %v", err)
+	}
+	if stats.Total != 2 || stats.Triggered != 2 {
+		t.Errorf("unexpected counts %+v", stats)
+	}
+	if stats.MTTASeconds != nil || stats.MTTRSeconds != nil {
+		t.Errorf("expected nil averages, got %v / %v", stats.MTTASeconds, stats.MTTRSeconds)
+	}
+}

internal/tui/model_test.go

@@ -0,0 +1,240 @@
+package tui
+
+import (
+	"testing"
+	"time"
+
+	"github.com/charmbracelet/bubbles/table"
+	"github.com/yeniklas/terdut-tui/internal/api"
+)
+
+func TestNextFilter(t *testing.T) {
+	tests := []struct {
+		name    string
+		cycle   []string
+		current string
+		want    string
+	}{
+		{"advances", incidentFilters, "", api.StatusTriggered},
+		{"advances again", incidentFilters, api.StatusTriggered, api.StatusAcknowledged},
+		{"wraps back to the open queue", incidentFilters, "snoozed", ""},
+		{"alerts advance", alertFilters, "firing", "resolved"},
+		{"alerts wrap", alertFilters, "archived", "firing"},
+		{"unknown current restarts the cycle", incidentFilters, "bogus", ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := nextFilter(tt.cycle, tt.current); got != tt.want {
+				t.Errorf("expected %q, got %q", tt.want, got)
+			}
+		})
+	}
+}
+
+// "snoozed" is a pseudo-status in the filter cycle: the server has no such
+// status, it is a separate query axis.
+func TestIncidentQuery(t *testing.T) {
+	tests := []struct {
+		filter      string
+		wantStatus  string
+		wantSnoozed bool
+	}{
+		{"", "", false},
+		{api.StatusTriggered, api.StatusTriggered, false},
+		{api.StatusResolved, api.StatusResolved, false},
+		{"snoozed", "", true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.filter, func(t *testing.T) {
+			status, snoozed := incidentQuery(tt.filter)
+			if status != tt.wantStatus || snoozed != tt.wantSnoozed {
+				t.Errorf("expected (%q, %v), got (%q, %v)",
+					tt.wantStatus, tt.wantSnoozed, status, snoozed)
+			}
+		})
+	}
+}
+
+func TestFilterLabel(t *testing.T) {
+	if got := filterLabel(""); got != "open" {
+		t.Errorf("the empty filter is the open queue, got %q", got)
+	}
+	if got := filterLabel("resolved"); got != "resolved" {
+		t.Errorf("expected resolved, got %q", got)
+	}
+}
+
+func TestNoteEvents(t *testing.T) {
+	timeline := []api.IncidentEvent{
+		{Type: api.EventTriggered},
+		{Type: api.EventNote, Detail: "first"},
+		{Type: api.EventAcknowledged},
+		{Type: api.EventNote, Detail: "second"},
+	}
+	notes := noteEvents(timeline)
+	if len(notes) != 2 {
+		t.Fatalf("expected 2 notes, got %d", len(notes))
+	}
+	if notes[0].Detail != "first" || notes[1].Detail != "second" {
+		t.Errorf("notes out of order: %v", notes)
+	}
+	if len(noteEvents(nil)) != 0 {
+		t.Error("an empty timeline has no notes")
+	}
+}
+
+func TestHumanDuration(t *testing.T) {
+	tests := []struct {
+		d    time.Duration
+		want string
+	}{
+		{5 * time.Second, "moments"},
+		{90 * time.Second, "1m"},
+		{45 * time.Minute, "45m"},
+		{2 * time.Hour, "2h"},
+		{150 * time.Minute, "2h 30m"},
+		{48 * time.Hour, "2d"},
+		{50 * time.Hour, "2d 2h"},
+	}
+	for _, tt := range tests {
+		if got := humanDuration(tt.d); got != tt.want {
+			t.Errorf("humanDuration(%v) = %q, want %q", tt.d, got, tt.want)
+		}
+	}
+}
+
+func TestHumanAgo_ClampsFutureToNow(t *testing.T) {
+	now := time.Now()
+	// Server and client clocks disagree often enough that this must not render
+	// as a negative age.
+	if got := humanAgo(now, now.Add(time.Hour)); got != "moments ago" {
+		t.Errorf("expected a future timestamp to clamp, got %q", got)
+	}
+}
+
+func TestHumanUntil(t *testing.T) {
+	now := time.Now()
+	if got := humanUntil(now, now.Add(2*time.Hour)); got != "in 2h" {
+		t.Errorf("expected 'in 2h', got %q", got)
+	}
+	if got := humanUntil(now, now.Add(-time.Minute)); got != "expired" {
+		t.Errorf("a deadline in the past has expired, got %q", got)
+	}
+}
+
+// MTTA and MTTR are nil until something has been acknowledged or resolved, and
+// that has to read as "no data" rather than an instant response.
+func TestHumanSeconds(t *testing.T) {
+	if got := humanSeconds(nil); got != "—" {
+		t.Errorf("expected an em dash for no data, got %q", got)
+	}
+	secs := 150.0
+	if got := humanSeconds(&secs); got != "2m" {
+		t.Errorf("expected 2m, got %q", got)
+	}
+}
+
+func TestIncidentRows(t *testing.T) {
+	future := time.Now().Add(time.Hour)
+	rows := incidentRows([]api.Incident{
+		{Title: "DiskFull", Status: api.StatusTriggered, Severity: "critical",
+			AssignedTo: "admin", TriggeredAt: time.Now()},
+		{Title: "Unowned", Status: api.StatusTriggered, TriggeredAt: time.Now()},
+		{Title: "Quiet", Status: api.StatusTriggered, Severity: "info",
+			AssignedTo: "alice", SnoozedUntil: &future, TriggeredAt: time.Now()},
+	})
+	if len(rows) != 3 {
+		t.Fatalf("expected 3 rows, got %d", len(rows))
+	}
+	if rows[0][0] != "critical" || rows[0][3] != "admin" {
+		t.Errorf("unexpected first row %v", rows[0])
+	}
+	if rows[1][0] != "—" || rows[1][3] != "—" {
+		t.Errorf("missing severity and assignee should show an em dash, got %v", rows[1])
+	}
+	// bubbles' table renders plain strings, so snooze has to be marked in text.
+	if rows[2][2] != "triggered (zzz)" {
+		t.Errorf("expected a snooze marker in the status cell, got %q", rows[2][2])
+	}
+}
+
+func TestAlertRows_ShowIncidentLink(t *testing.T) {
+	id := int64(7)
+	rows := alertRows([]api.Alert{
+		{Name: "DiskFull", Status: "firing", IncidentID: &id},
+		{Name: "Orphan", Status: "resolved"},
+	})
+	if rows[0][4] != "#7" {
+		t.Errorf("expected #7, got %q", rows[0][4])
+	}
+	if rows[1][4] != "—" {
+		t.Errorf("an alert with no incident shows an em dash, got %q", rows[1][4])
+	}
+}
+
+// A previous release overflowed the terminal by two columns because the padding
+// budget was wrong. Columns plus bubbles' per-cell padding must land exactly on
+// the window width.
+func TestColumnWidthsFitTheTerminal(t *testing.T) {
+	for _, width := range []int{100, 110, 140, 200} {
+		for name, cols := range map[string][]int{
+			"incident": widths(incidentColumns(width)),
+			"alert":    widths(alertColumns(width)),
+		} {
+			sum := 0
+			for _, w := range cols {
+				sum += w
+			}
+			const padding = 10 // bubbles applies Padding(0, 1) to each of five cells
+			if sum+padding != width {
+				t.Errorf("%s columns at width %d sum to %d+%d = %d",
+					name, width, sum, padding, sum+padding)
+			}
+		}
+	}
+}
+
+// Narrow terminals fall back to minimum widths, which legitimately overflow;
+// what must not happen is a negative or zero column.
+func TestColumnWidthsStayPositiveWhenNarrow(t *testing.T) {
+	for _, width := range []int{20, 40, 60} {
+		for _, w := range append(widths(incidentColumns(width)), widths(alertColumns(width))...) {
+			if w < 1 {
+				t.Errorf("width %d produced a non-positive column %d", width, w)
+			}
+		}
+	}
+}
+
+func widths(cols []table.Column) []int {
+	out := make([]int, len(cols))
+	for i, c := range cols {
+		out[i] = c.Width
+	}
+	return out
+}
+
+func TestTableHeight_NeverGoesBelowOne(t *testing.T) {
+	if got := tableHeight(3, 10); got != 1 {
+		t.Errorf("expected a floor of 1, got %d", got)
+	}
+	if got := tableHeight(40, 8); got != 32 {
+		t.Errorf("expected 32, got %d", got)
+	}
+}
+
+func TestBuildScheduleDays(t *testing.T) {
+	monday := time.Date(2026, 7, 27, 0, 0, 0, 0, time.UTC)
+	days := buildScheduleDays(monday, []api.ScheduleEntry{
+		{Date: "2026-07-29", Username: "alice"},
+	})
+	if len(days) != 7 {
+		t.Fatalf("expected a 7-day window, got %d", len(days))
+	}
+	if days[2].entry == nil || days[2].entry.Username != "alice" {
+		t.Errorf("expected alice on the third day, got %+v", days[2].entry)
+	}
+	if days[0].entry != nil {
+		t.Error("expected unassigned days to have no entry")
+	}
+}

internal/tui/update_test.go

@@ -0,0 +1,467 @@
+package tui
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/yeniklas/terdut-tui/internal/api"
+)
+
+// press sends one key and returns the resulting model and command. A nil command
+// means the model decided to do nothing, which is what most of these tests are
+// really asserting.
+func press(t *testing.T, m Model, key string) (Model, tea.Cmd) {
+	t.Helper()
+	var msg tea.KeyMsg
+	switch key {
+	case "esc":
+		msg = tea.KeyMsg{Type: tea.KeyEsc}
+	case "enter":
+		msg = tea.KeyMsg{Type: tea.KeyEnter}
+	case "tab":
+		msg = tea.KeyMsg{Type: tea.KeyTab}
+	default:
+		msg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune(key)}
+	}
+	next, cmd := m.Update(msg)
+	return next.(Model), cmd
+}
+
+// sized returns a connected model with a usable window, which most handlers need.
+func sized() Model {
+	m := NewModel(nil, "http://test", time.Minute)
+	m.width, m.height = 120, 40
+	m.connected = true
+	return m
+}
+
+// onIncident opens the incident detail view directly, skipping the fetch.
+func onIncident(inc api.Incident, timeline []api.IncidentEvent) Model {
+	m := sized()
+	m.mode = modeIncidentDetail
+	m.selectedIncident = inc
+	m.timeline = timeline
+	m.noteCursor = -1
+	return m
+}
+
+func openIncidentFixture() api.Incident {
+	return api.Incident{ID: 1, Title: "DiskFull", Status: api.StatusTriggered,
+		Severity: "critical", TriggeredAt: time.Now()}
+}
+
+func resolvedIncidentFixture() api.Incident {
+	now := time.Now()
+	source := "manual"
+	inc := openIncidentFixture()
+	inc.Status = api.StatusResolved
+	inc.ResolvedAt = &now
+	inc.ResolutionSource = &source
+	return inc
+}
+
+// Resolving is terminal on the server: a later occurrence opens a new incident
+// rather than reopening this one. A stray keypress must not be able to do that.
+func TestResolve_AsksBeforeDoingIt(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+
+	m, cmd := press(t, m, "R")
+	if m.mode != modeConfirm {
+		t.Fatalf("expected a confirmation prompt, got mode %v", m.mode)
+	}
+	if m.confirmTarget != confirmResolveIncident {
+		t.Errorf("expected the resolve target, got %v", m.confirmTarget)
+	}
+	if cmd != nil {
+		t.Error("nothing should be sent to the server before confirming")
+	}
+	if !containsAll(m.confirmPrompt(), "final", "new incident") {
+		t.Errorf("the prompt should say resolving is final, got %q", m.confirmPrompt())
+	}
+}
+
+func TestResolve_CancelReturnsToDetailWithoutActing(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+	m, _ = press(t, m, "R")
+
+	m, cmd := press(t, m, "n")
+	if m.mode != modeIncidentDetail {
+		t.Errorf("expected to land back on the incident, got mode %v", m.mode)
+	}
+	if cmd != nil {
+		t.Error("cancelling must not act")
+	}
+}
+
+func TestResolve_ConfirmActs(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+	m, _ = press(t, m, "R")
+
+	m, cmd := press(t, m, "y")
+	if cmd == nil {
+		t.Error("confirming should issue the resolve")
+	}
+	if m.mode != modeIncidentDetail {
+		t.Errorf("expected to return to the incident, got mode %v", m.mode)
+	}
+}
+
+// The server answers 409 on all of these; saying so up front beats a round trip.
+func TestResolvedIncident_RejectsWorkflowActions(t *testing.T) {
+	for _, key := range []string{"a", "A", "R", "s", "z", "Z"} {
+		t.Run(key, func(t *testing.T) {
+			m := onIncident(resolvedIncidentFixture(), nil)
+			m, cmd := press(t, m, key)
+			if cmd == nil {
+				t.Error("expected a status message command")
+			}
+			if m.statusMsg == "" {
+				t.Error("expected an explanation in the status line")
+			}
+			if m.mode != modeIncidentDetail {
+				t.Errorf("expected to stay on the incident, got mode %v", m.mode)
+			}
+		})
+	}
+}
+
+func TestOpenIncident_AcknowledgeTwiceIsRejected(t *testing.T) {
+	inc := openIncidentFixture()
+	id := int64(2)
+	at := time.Now()
+	inc.Status = api.StatusAcknowledged
+	inc.AcknowledgedByID = &id
+	inc.AcknowledgedBy = "alice"
+	inc.AcknowledgedAt = &at
+
+	m, _ := press(t, onIncident(inc, nil), "a")
+	if !containsAll(m.statusMsg, "already acknowledged", "alice") {
+		t.Errorf("expected to be told who holds it, got %q", m.statusMsg)
+	}
+}
+
+func TestOpenIncident_UnacknowledgeRequiresAnAcknowledgement(t *testing.T) {
+	m, _ := press(t, onIncident(openIncidentFixture(), nil), "A")
+	if m.statusMsg != "not acknowledged" {
+		t.Errorf("expected 'not acknowledged', got %q", m.statusMsg)
+	}
+}
+
+func TestOpenIncident_UnsnoozeRequiresASnooze(t *testing.T) {
+	m, _ := press(t, onIncident(openIncidentFixture(), nil), "Z")
+	if m.statusMsg != "not snoozed" {
+		t.Errorf("expected 'not snoozed', got %q", m.statusMsg)
+	}
+}
+
+// Archiving unresolved work only hides it, so the client refuses rather than
+// letting the queue be cleared by pressing x.
+func TestArchive_RefusesOpenIncident(t *testing.T) {
+	t.Run("from the detail view", func(t *testing.T) {
+		m, cmd := press(t, onIncident(openIncidentFixture(), nil), "x")
+		if cmd == nil || m.statusMsg == "" {
+			t.Error("expected a refusal message")
+		}
+		if m.mode != modeIncidentDetail {
+			t.Errorf("expected to stay put, got mode %v", m.mode)
+		}
+	})
+
+	t.Run("from the queue", func(t *testing.T) {
+		m := sized()
+		m.incidents = []api.Incident{openIncidentFixture()}
+		m.rebuildIncidentTable()
+
+		m, _ = press(t, m, "x")
+		if m.statusMsg == "" {
+			t.Error("expected a refusal message")
+		}
+	})
+}
+
+func TestArchive_AllowedOnResolvedIncident(t *testing.T) {
+	m := sized()
+	m.incidents = []api.Incident{resolvedIncidentFixture()}
+	m.rebuildIncidentTable()
+
+	m, cmd := press(t, m, "x")
+	if cmd == nil {
+		t.Error("archiving a resolved incident should act")
+	}
+	if m.statusMsg != "" {
+		t.Errorf("expected no refusal, got %q", m.statusMsg)
+	}
+}
+
+func TestSnooze_PromptThenSubmit(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+
+	m, _ = press(t, m, "z")
+	if m.mode != modeSnooze {
+		t.Fatalf("expected the snooze prompt, got mode %v", m.mode)
+	}
+
+	// Typing goes to the input, not the key handler.
+	for _, r := range "2h" {
+		m, _ = press(t, m, string(r))
+	}
+	if m.snoozeInput.Value() != "2h" {
+		t.Fatalf("expected the typed duration, got %q", m.snoozeInput.Value())
+	}
+
+	m, cmd := press(t, m, "enter")
+	if cmd == nil {
+		t.Error("expected the snooze to be sent")
+	}
+	if m.mode != modeIncidentDetail {
+		t.Errorf("expected to return to the incident, got mode %v", m.mode)
+	}
+}
+
+func TestSnooze_EmptyInputDoesNothing(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+	m, _ = press(t, m, "z")
+
+	m, cmd := press(t, m, "enter")
+	if cmd != nil {
+		t.Error("an empty duration should not be sent")
+	}
+	if m.mode != modeSnooze {
+		t.Errorf("expected to stay on the prompt, got mode %v", m.mode)
+	}
+}
+
+func TestNote_EscapeAbandonsWithoutPosting(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+	m, _ = press(t, m, "c")
+	if m.mode != modeNote {
+		t.Fatalf("expected the note prompt, got mode %v", m.mode)
+	}
+
+	m, cmd := press(t, m, "esc")
+	if cmd != nil {
+		t.Error("escaping must not post the note")
+	}
+	if m.mode != modeIncidentDetail {
+		t.Errorf("expected to return to the incident, got mode %v", m.mode)
+	}
+}
+
+func TestNoteCursor_WrapsOverNotesOnly(t *testing.T) {
+	timeline := []api.IncidentEvent{
+		{ID: 1, Type: api.EventTriggered},
+		{ID: 2, Type: api.EventNote, Detail: "first"},
+		{ID: 3, Type: api.EventAcknowledged},
+		{ID: 4, Type: api.EventNote, Detail: "second"},
+	}
+	m := onIncident(openIncidentFixture(), timeline)
+
+	m, _ = press(t, m, "]")
+	if m.noteCursor != 0 {
+		t.Fatalf("expected the first note, got %d", m.noteCursor)
+	}
+	m, _ = press(t, m, "]")
+	if m.noteCursor != 1 {
+		t.Fatalf("expected the second note, got %d", m.noteCursor)
+	}
+	m, _ = press(t, m, "]")
+	if m.noteCursor != 0 {
+		t.Errorf("expected to wrap to the first note, got %d", m.noteCursor)
+	}
+	m, _ = press(t, m, "[")
+	if m.noteCursor != 1 {
+		t.Errorf("expected to wrap backwards to the last note, got %d", m.noteCursor)
+	}
+}
+
+func TestDeleteNote_RequiresASelection(t *testing.T) {
+	m := onIncident(openIncidentFixture(), []api.IncidentEvent{{Type: api.EventTriggered}})
+	m, _ = press(t, m, "d")
+	if m.mode == modeConfirm {
+		t.Error("nothing is selected, so there is nothing to confirm")
+	}
+	if !containsAll(m.statusMsg, "select a note") {
+		t.Errorf("expected guidance, got %q", m.statusMsg)
+	}
+}
+
+func TestDeleteNote_ConfirmsThenActs(t *testing.T) {
+	timeline := []api.IncidentEvent{{ID: 9, Type: api.EventNote, Detail: "hi"}}
+	m := onIncident(openIncidentFixture(), timeline)
+
+	m, _ = press(t, m, "]")
+	m, _ = press(t, m, "d")
+	if m.mode != modeConfirm || m.confirmTarget != confirmDeleteNote {
+		t.Fatalf("expected a delete confirmation, got mode %v target %v", m.mode, m.confirmTarget)
+	}
+	if m.pendingDeleteID != 9 {
+		t.Errorf("expected the selected note's id, got %d", m.pendingDeleteID)
+	}
+
+	m, cmd := press(t, m, "y")
+	if cmd == nil {
+		t.Error("confirming should issue the delete")
+	}
+	if m.mode != modeIncidentDetail {
+		t.Errorf("expected to return to the incident, got mode %v", m.mode)
+	}
+}
+
+func TestTab_CyclesEverySection(t *testing.T) {
+	m := sized()
+	if m.activeSection != sectionIncidents {
+		t.Fatal("incidents is the section the client opens on")
+	}
+
+	want := []section{sectionAlerts, sectionArchived, sectionSchedule, sectionUsers, sectionIncidents}
+	for i, expected := range want {
+		m, _ = press(t, m, "tab")
+		if m.activeSection != expected {
+			t.Fatalf("after %d tabs expected section %v, got %v", i+1, expected, m.activeSection)
+		}
+	}
+}
+
+func TestFilter_CyclesPerSection(t *testing.T) {
+	m := sized()
+	m, _ = press(t, m, "f")
+	if m.incidentFilter != api.StatusTriggered {
+		t.Errorf("expected the incident filter to advance, got %q", m.incidentFilter)
+	}
+
+	m.activeSection = sectionAlerts
+	m, _ = press(t, m, "f")
+	if m.alertFilter != "resolved" {
+		t.Errorf("expected the alert filter to advance, got %q", m.alertFilter)
+	}
+	if m.incidentFilter != api.StatusTriggered {
+		t.Error("the two filters are independent")
+	}
+}
+
+// Stats opens from both the queue and an incident, and esc has to go back to
+// wherever it was opened from.
+func TestStats_ReturnsWhereItWasOpenedFrom(t *testing.T) {
+	t.Run("from the queue", func(t *testing.T) {
+		m, _ := press(t, sized(), "S")
+		if m.mode != modeStats {
+			t.Fatalf("expected stats, got mode %v", m.mode)
+		}
+		m, _ = press(t, m, "esc")
+		if m.mode != modeDashboard {
+			t.Errorf("expected the dashboard, got mode %v", m.mode)
+		}
+	})
+
+	t.Run("from an incident", func(t *testing.T) {
+		m, _ := press(t, onIncident(openIncidentFixture(), nil), "S")
+		if m.mode != modeStats {
+			t.Fatalf("expected stats, got mode %v", m.mode)
+		}
+		m, _ = press(t, m, "esc")
+		if m.mode != modeIncidentDetail {
+			t.Errorf("expected the incident, got mode %v", m.mode)
+		}
+	})
+}
+
+// Alerts carry no workflow state, so the detail view offers nothing but a way
+// through to the incident.
+func TestAlertDetail_IsReadOnly(t *testing.T) {
+	m := sized()
+	m.mode = modeAlertDetail
+	m.selectedAlert = api.Alert{ID: 3, Name: "DiskFull", Status: "firing"}
+
+	for _, key := range []string{"a", "A", "R", "c", "x", "z"} {
+		next, cmd := press(t, m, key)
+		if cmd != nil {
+			t.Errorf("key %q should do nothing on an alert", key)
+		}
+		if next.mode != modeAlertDetail {
+			t.Errorf("key %q changed mode to %v", key, next.mode)
+		}
+	}
+}
+
+func TestAlertDetail_JumpToIncident(t *testing.T) {
+	m := sized()
+	m.mode = modeAlertDetail
+
+	t.Run("without an incident", func(t *testing.T) {
+		m.selectedAlert = api.Alert{ID: 3, Name: "Orphan"}
+		next, _ := press(t, m, "i")
+		if next.mode != modeAlertDetail || next.statusMsg == "" {
+			t.Errorf("expected a refusal, got mode %v msg %q", next.mode, next.statusMsg)
+		}
+	})
+
+	t.Run("with an incident", func(t *testing.T) {
+		id := int64(7)
+		m.selectedAlert = api.Alert{ID: 3, Name: "DiskFull", IncidentID: &id}
+		next, cmd := press(t, m, "i")
+		if next.mode != modeIncidentDetail {
+			t.Fatalf("expected the incident view, got mode %v", next.mode)
+		}
+		if next.selectedIncident.ID != 7 {
+			t.Errorf("expected incident 7, got %d", next.selectedIncident.ID)
+		}
+		if cmd == nil {
+			t.Error("expected the incident to be fetched")
+		}
+	})
+}
+
+// A refresh underneath a prompt would move the ground under the user.
+func TestRefreshTick_SkipsModalStates(t *testing.T) {
+	modal := []mode{modeNote, modeSnooze, modeConfirm, modeUserPicker, modeUserCreate}
+	for _, md := range modal {
+		m := sized()
+		m.mode = md
+		if cmd := m.refreshActiveSection(); cmd != nil {
+			t.Errorf("mode %v should not auto-refresh", md)
+		}
+	}
+
+	m := sized()
+	if cmd := m.refreshActiveSection(); cmd == nil {
+		t.Error("the dashboard should auto-refresh")
+	}
+}
+
+func TestIncidentsFetched_ClearsLoading(t *testing.T) {
+	m := sized()
+	m.loading = true
+	next, _ := m.Update(incidentsFetchedMsg{incidents: []api.Incident{openIncidentFixture()}})
+	got := next.(Model)
+	if got.loading {
+		t.Error("expected loading to clear")
+	}
+	if len(got.incidents) != 1 {
+		t.Errorf("expected the incidents stored, got %d", len(got.incidents))
+	}
+}
+
+// A note deleted elsewhere must not leave the cursor pointing past the end.
+func TestIncidentDetailFetched_ClampsNoteCursor(t *testing.T) {
+	m := onIncident(openIncidentFixture(), nil)
+	m.noteCursor = 3
+
+	next, _ := m.Update(incidentDetailFetchedMsg{
+		incident: openIncidentFixture(),
+		timeline: []api.IncidentEvent{{Type: api.EventTriggered}},
+	})
+	if got := next.(Model).noteCursor; got != -1 {
+		t.Errorf("expected the cursor reset, got %d", got)
+	}
+}
+
+func containsAll(s string, subs ...string) bool {
+	for _, sub := range subs {
+		if !strings.Contains(s, sub) {
+			return false
+		}
+	}
+	return true
+}

internal/tui/view.go

@@ -365,6 +365,16 @@ func (m Model) renderStats() string {
 	return m.statsViewport.View()
 }
 
+// line renders s in a style and terminates it.
+//
+// The newline has to stay outside Render: lipgloss pads every line of a styled
+// block out to its widest line, so a trailing newline inside the block produces
+// a second line made entirely of padding, and whatever is written next starts
+// after that padding instead of at the left margin.
+func line(style lipgloss.Style, s string) string {
+	return style.Render(s) + "\n"
+}
+
 // ── Content builders ───────────────────────────────────────────────────────
 
 func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent, cursor, width int) string {
@@ -391,7 +401,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	if inc.AssignedTo != "" {
 		b.WriteString(fmt.Sprintf("  Assigned:   %s\n", styleBold.Render(inc.AssignedTo)))
 	} else {
-		b.WriteString(styleMuted.Render("  Assigned:   nobody\n"))
+		b.WriteString(line(styleMuted, "  Assigned:   nobody"))
 	}
 
 	if inc.AcknowledgedByID != nil {
@@ -399,14 +409,14 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 		if inc.AcknowledgedAt != nil {
 			ackAt = "  at " + inc.AcknowledgedAt.UTC().Format("2006-01-02 15:04 UTC")
 		}
-		b.WriteString(styleResolved.Render(
+		b.WriteString(line(styleResolved,
-			fmt.Sprintf("  Acked:      %s%s\n", inc.AcknowledgedBy, ackAt)))
+			fmt.Sprintf("  Acked:      %s%s", inc.AcknowledgedBy, ackAt)))
 	} else {
-		b.WriteString(styleMuted.Render("  Acked:      not acknowledged\n"))
+		b.WriteString(line(styleMuted, "  Acked:      not acknowledged"))
 	}
 
 	if inc.IsSnoozed() {
-		b.WriteString(styleSnoozed.Render(fmt.Sprintf("  Snoozed:    until %s  (%s)\n",
+		b.WriteString(line(styleSnoozed, fmt.Sprintf("  Snoozed:    until %s  (%s)",
 			inc.SnoozedUntil.UTC().Format("2006-01-02 15:04 UTC"), humanUntil(now, *inc.SnoozedUntil))))
 	}
 
@@ -419,8 +429,8 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 			inc.ResolvedAt.UTC().Format("2006-01-02 15:04 UTC"), humanAgo(now, *inc.ResolvedAt), source))
 	}
 	if inc.ArchivedAt != nil {
-		b.WriteString(styleMuted.Render("  Archived:   " +
+		b.WriteString(line(styleMuted, "  Archived:   "+
-			inc.ArchivedAt.UTC().Format("2006-01-02 15:04 UTC") + "\n"))
+			inc.ArchivedAt.UTC().Format("2006-01-02 15:04 UTC")))
 	}
 	b.WriteString("\n")
 
@@ -436,7 +446,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	// Member alerts
 	b.WriteString(divider(fmt.Sprintf("Alerts (%d)", len(inc.Alerts)), width))
 	if len(inc.Alerts) == 0 {
-		b.WriteString(styleMuted.Render("  No alerts.\n"))
+		b.WriteString(line(styleMuted, "  No alerts."))
 	} else {
 		for _, a := range inc.Alerts {
 			marker := styleFiring.Render("●")
@@ -458,7 +468,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	notes := noteEvents(timeline)
 	b.WriteString(divider(fmt.Sprintf("Timeline (%d events, %d notes)", len(timeline), len(notes)), width))
 	if len(timeline) == 0 {
-		b.WriteString(styleMuted.Render("  Nothing recorded yet.\n"))
+		b.WriteString(line(styleMuted, "  Nothing recorded yet."))
 	} else {
 		noteIndex := 0
 		for _, e := range timeline {
@@ -584,7 +594,7 @@ func buildAlertDetailContent(alert api.Alert, width int) string {
 			styleBold.Render(fmt.Sprintf("#%d", *alert.IncidentID)),
 			styleMuted.Render("press i to open it")))
 	} else {
-		b.WriteString(styleMuted.Render("  Incident:   none\n"))
+		b.WriteString(line(styleMuted, "  Incident:   none"))
 	}
 	b.WriteString("\n")
 
@@ -606,8 +616,8 @@ func buildAlertDetailContent(alert api.Alert, width int) string {
 
 	// Alerts carry no workflow state: it all lives on the incident.
 	b.WriteString(divider("", width))
-	b.WriteString(styleMuted.Render(
+	b.WriteString(line(styleMuted,
-		"  Alerts are read-only — acknowledge, assign, note and resolve on the incident.\n"))
+		"  Alerts are read-only — acknowledge, assign, note and resolve on the incident."))
 
 	return b.String()
 }
@@ -627,7 +637,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 	// Response times first: they are what a rota is actually judged on.
 	b.WriteString(divider("Incident Response", width))
 	if incidents == nil {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	} else {
 		b.WriteString(fmt.Sprintf("  %-28s %s\n", "Incidents total",
 			styleBold.Render(fmt.Sprintf("%d", incidents.Total))))
@@ -642,14 +652,14 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 		b.WriteString(fmt.Sprintf("  %-28s %s\n", "Mean time to resolve",
 			styleBold.Render(humanSeconds(incidents.MTTRSeconds))))
 		if incidents.MTTASeconds == nil || incidents.MTTRSeconds == nil {
-			b.WriteString(styleMuted.Render("  (— means nothing has been acknowledged or resolved yet)\n"))
+			b.WriteString(line(styleMuted, "  (— means nothing has been acknowledged or resolved yet)"))
 		}
 	}
 	b.WriteString("\n")
 
 	b.WriteString(divider("Top Alerts", width))
 	if len(top) == 0 {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	} else {
 		maxCount := top[0].Count
 		for i, a := range top {
@@ -672,7 +682,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 			b.WriteString(fmt.Sprintf("  %2dh  %-*s %d\n", h.Hour, barWidth, bar, h.Count))
 		}
 	} else {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	}
 	b.WriteString("\n")
 
@@ -689,7 +699,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 			b.WriteString(fmt.Sprintf("  %-4s  %-*s %d\n", d.DayName[:3], barWidth, bar, d.Count))
 		}
 	} else {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	}
 
 	return b.String()
@@ -723,7 +733,7 @@ func (m Model) renderUserCreate() string {
 
 func (m Model) renderAPIKeyMenu() string {
 	header := fmt.Sprintf("\n  API keys for %s\n", styleBold.Render(m.selectedUser.Username))
-	warning := styleMuted.Render("  Keys cannot be listed — only new keys can be created,\n  or existing ones revoked by their integer ID.\n")
+	warning := line(styleMuted, "  Keys cannot be listed — only new keys can be created,\n  or existing ones revoked by their integer ID.")
 	options := "\n" +
 		styleAccent.Render("  n") + "  · create a new API key\n" +
 		styleAccent.Render("  r") + "  · revoke a key by ID\n"
@@ -757,7 +767,7 @@ func (m Model) renderAPIKeyReveal() string {
 
 func (m Model) renderAPIKeyRevokeByID() string {
 	header := fmt.Sprintf("\n  Revoke API key for %s\n", styleBold.Render(m.selectedUser.Username))
-	hint := styleMuted.Render("  Enter the integer key ID (shown when the key was created).\n")
+	hint := line(styleMuted, "  Enter the integer key ID (shown when the key was created).")
 	label := styleSelected.Render("  Key ID:  ")
 	return header + "\n" + hint + "\n" + label + m.apiKeyRevokeInput.View() + "\n"
 }

internal/tui/view_test.go

@@ -0,0 +1,286 @@
+package tui
+
+import (
+	"regexp"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/yeniklas/terdut-tui/internal/api"
+)
+
+// ansi matches the escape sequences lipgloss emits when it decides the output
+// supports colour, so assertions can be made against the text alone.
+var ansi = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+
+func plain(s string) string { return ansi.ReplaceAllString(s, "") }
+
+func mustContain(t *testing.T, got string, wants ...string) {
+	t.Helper()
+	got = plain(got)
+	for _, w := range wants {
+		if !strings.Contains(got, w) {
+			t.Errorf("expected output to contain %q\n--- got ---\n%s", w, got)
+		}
+	}
+}
+
+func TestIncidentDetail_RendersTheWholeStory(t *testing.T) {
+	now := time.Now()
+	ackID := int64(1)
+	alertID := int64(3)
+	inc := api.Incident{
+		ID: 1, Title: "DiskFull (namespace=prod)", Status: api.StatusAcknowledged,
+		Severity:    "critical",
+		GroupLabels: map[string]string{"alertname": "DiskFull", "namespace": "prod"},
+		TriggeredAt: now.Add(-2 * time.Hour),
+		AssignedTo:  "admin", AcknowledgedByID: &ackID, AcknowledgedBy: "admin",
+		AcknowledgedAt: &now,
+		Alerts: []api.Alert{
+			{ID: 3, Name: "DiskFull", Status: "firing",
+				Labels: map[string]string{"instance": "node-1"}, ReceivedAt: now},
+			{ID: 4, Name: "DiskFull", Status: "resolved",
+				Labels: map[string]string{"instance": "node-2"}, ReceivedAt: now},
+		},
+	}
+	timeline := []api.IncidentEvent{
+		{Type: api.EventTriggered, CreatedAt: now},
+		{Type: api.EventAssigned, Username: "admin", CreatedAt: now},
+		{Type: api.EventAlertAdded, AlertID: &alertID, CreatedAt: now},
+		{Type: api.EventAcknowledged, Username: "admin", CreatedAt: now},
+		{Type: api.EventNote, Username: "admin", Detail: "draining node-2", CreatedAt: now},
+	}
+
+	out := buildIncidentDetailContent(inc, timeline, -1, 110)
+	mustContain(t, out,
+		"DiskFull (namespace=prod)", "ACKNOWLEDGED", "CRITICAL",
+		"Assigned:", "admin",
+		"Grouped By", "namespace", "prod",
+		"Alerts (2)", "node-1", "node-2",
+		"Timeline (5 events, 1 notes)",
+		"Incident opened", "Assigned to admin", "Alert #3 joined", "Acknowledged by admin",
+		"admin wrote", "draining node-2",
+	)
+}
+
+func TestIncidentDetail_ShowsSnooze(t *testing.T) {
+	future := time.Now().Add(2 * time.Hour)
+	inc := api.Incident{
+		Title: "Noisy", Status: api.StatusTriggered,
+		TriggeredAt: time.Now(), SnoozedUntil: &future,
+	}
+	// The exact remaining time is humanUntil's business, not this test's — a few
+	// microseconds of elapsed clock turn "in 2h" into "in 1h 59m".
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110),
+		"TRIGGERED (snoozed)", "Snoozed:", "until", "in 1h")
+}
+
+// An expired snooze is not a snooze, so it must not be reported as one.
+func TestIncidentDetail_HidesExpiredSnooze(t *testing.T) {
+	past := time.Now().Add(-time.Hour)
+	inc := api.Incident{
+		Title: "Noisy", Status: api.StatusTriggered,
+		TriggeredAt: time.Now(), SnoozedUntil: &past,
+	}
+	if strings.Contains(plain(buildIncidentDetailContent(inc, nil, -1, 110)), "Snoozed:") {
+		t.Error("an expired snooze should not be rendered")
+	}
+}
+
+func TestIncidentDetail_ShowsResolutionSource(t *testing.T) {
+	now := time.Now()
+	source := "manual"
+	inc := api.Incident{
+		Title: "Done", Status: api.StatusResolved, TriggeredAt: now.Add(-time.Hour),
+		ResolvedAt: &now, ResolutionSource: &source,
+	}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110),
+		"RESOLVED", "Resolved:", "manual")
+}
+
+func TestIncidentDetail_UnassignedAndUnacknowledged(t *testing.T) {
+	inc := api.Incident{Title: "Fresh", Status: api.StatusTriggered, TriggeredAt: time.Now()}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110), "nobody", "not acknowledged")
+}
+
+func TestIncidentDetail_EmptyTimeline(t *testing.T) {
+	inc := api.Incident{Title: "Fresh", Status: api.StatusTriggered, TriggeredAt: time.Now()}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110), "Nothing recorded yet")
+}
+
+func TestIncidentDetail_MarksSelectedNote(t *testing.T) {
+	now := time.Now()
+	timeline := []api.IncidentEvent{
+		{Type: api.EventNote, Username: "admin", Detail: "first", CreatedAt: now},
+		{Type: api.EventNote, Username: "alice", Detail: "second", CreatedAt: now},
+	}
+	inc := api.Incident{Title: "X", Status: api.StatusTriggered, TriggeredAt: now}
+
+	out := plain(buildIncidentDetailContent(inc, timeline, 1, 110))
+	for _, line := range strings.Split(out, "\n") {
+		if strings.Contains(line, "alice") && !strings.HasPrefix(line, "> ") {
+			t.Errorf("expected the selected note marked, got %q", line)
+		}
+		if strings.Contains(line, "admin wrote") && strings.HasPrefix(line, "> ") {
+			t.Errorf("expected the unselected note unmarked, got %q", line)
+		}
+	}
+}
+
+func TestIncidentStatusLabel(t *testing.T) {
+	future := time.Now().Add(time.Hour)
+	tests := []struct {
+		name string
+		inc  api.Incident
+		want string
+	}{
+		{"triggered", api.Incident{Status: api.StatusTriggered}, "● TRIGGERED"},
+		{"acknowledged", api.Incident{Status: api.StatusAcknowledged}, "◐ ACKNOWLEDGED"},
+		{"resolved", api.Incident{Status: api.StatusResolved}, "✓ RESOLVED"},
+		{"snoozed", api.Incident{Status: api.StatusTriggered, SnoozedUntil: &future},
+			"● TRIGGERED (snoozed)"},
+		// A status this client does not know about still has to render.
+		{"unknown", api.Incident{Status: "escalated"}, "ESCALATED"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := incidentStatusLabel(tt.inc); got != tt.want {
+				t.Errorf("expected %q, got %q", tt.want, got)
+			}
+		})
+	}
+}
+
+// The server may add event types after this client ships. An unknown one must
+// still appear on the timeline rather than silently vanishing.
+func TestEventLabel_UnknownTypeFallsBackToItsName(t *testing.T) {
+	got := eventLabel(api.IncidentEvent{Type: "escalated", Detail: "to sre-oncall"})
+	mustContain(t, got, "escalated", "to sre-oncall")
+}
+
+func TestEventLabel_KnownTypes(t *testing.T) {
+	alertID := int64(9)
+	tests := []struct {
+		event api.IncidentEvent
+		want  string
+	}{
+		{api.IncidentEvent{Type: api.EventTriggered}, "Incident opened"},
+		{api.IncidentEvent{Type: api.EventAlertAdded, AlertID: &alertID}, "Alert #9 joined"},
+		{api.IncidentEvent{Type: api.EventAlertResolved, AlertID: &alertID}, "Alert #9 resolved"},
+		{api.IncidentEvent{Type: api.EventAcknowledged, Username: "bo"}, "Acknowledged by bo"},
+		{api.IncidentEvent{Type: api.EventAssigned, Username: "bo"}, "Assigned to bo"},
+		{api.IncidentEvent{Type: api.EventSnoozed, Detail: "2026-08-01T00:00:00Z"},
+			"Snoozed until 2026-08-01T00:00:00Z"},
+		{api.IncidentEvent{Type: api.EventResolved, Username: "bo"}, "Resolved by bo"},
+		// No user means the server closed it via the alert cascade.
+		{api.IncidentEvent{Type: api.EventResolved}, "all alerts stopped firing"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.event.Type, func(t *testing.T) {
+			mustContain(t, eventLabel(tt.event), tt.want)
+		})
+	}
+}
+
+func TestAlertDetail_SaysItIsReadOnlyAndLinksTheIncident(t *testing.T) {
+	now := time.Now()
+	id := int64(7)
+	alert := api.Alert{
+		ID: 3, Name: "DiskFull", Status: "firing", StartsAt: now.Add(-time.Hour),
+		ReceivedAt: now, IncidentID: &id,
+		Labels:      map[string]string{"instance": "node-1", "severity": "critical"},
+		Annotations: map[string]string{"summary": "disk 90%"},
+	}
+	mustContain(t, buildAlertDetailContent(alert, 110),
+		"DiskFull", "FIRING", "Incident:", "#7", "press i to open it",
+		"instance", "node-1", "summary", "disk 90%",
+		"Alerts are read-only")
+}
+
+func TestAlertDetail_NoIncident(t *testing.T) {
+	alert := api.Alert{ID: 3, Name: "Orphan", Status: "resolved", ReceivedAt: time.Now()}
+	mustContain(t, buildAlertDetailContent(alert, 110), "Incident:", "none")
+}
+
+func TestAlertDetail_ShowsResolutionSource(t *testing.T) {
+	source := "expiry"
+	alert := api.Alert{Name: "Gone", Status: "resolved", ReceivedAt: time.Now(),
+		ResolutionSource: &source}
+	mustContain(t, buildAlertDetailContent(alert, 110), "RESOLVED", "expiry")
+}
+
+// Null MTTA means nothing has been acknowledged, which is a different claim
+// from an instant response.
+func TestStats_RendersDashForMissingAverages(t *testing.T) {
+	stats := &api.IncidentStats{Total: 2, Triggered: 2}
+	out := buildStatsContent(stats, nil, nil, nil, 110)
+	mustContain(t, out, "Incident Response", "Mean time to acknowledge", "—",
+		"nothing has been acknowledged or resolved yet")
+}
+
+func TestStats_RendersAverages(t *testing.T) {
+	mtta, mttr := 150.0, 3600.0
+	stats := &api.IncidentStats{Total: 3, Resolved: 1, MTTASeconds: &mtta, MTTRSeconds: &mttr}
+	out := buildStatsContent(stats, []api.TopAlert{{Name: "DiskFull", Count: 4}}, nil, nil, 110)
+	mustContain(t, out, "2m", "1h", "Top Alerts", "DiskFull")
+}
+
+func TestStats_HandlesNoIncidentData(t *testing.T) {
+	mustContain(t, buildStatsContent(nil, nil, nil, nil, 110), "Incident Response", "No data")
+}
+
+func TestView_TabsAndDashboardRender(t *testing.T) {
+	m := sized()
+	m.incidents = []api.Incident{{
+		ID: 1, Title: "DiskFull", Status: api.StatusTriggered, Severity: "critical",
+		AssignedTo: "admin", TriggeredAt: time.Now(),
+	}}
+	m.incidentStats = &api.IncidentStats{Triggered: 1}
+	m.rebuildIncidentTable()
+
+	mustContain(t, m.View(),
+		"Incidents", "Alerts", "Archived", "Schedule", "Users",
+		"Triggered: 1", "filter: open",
+		"DiskFull", "critical", "admin",
+		"enter·detail")
+}
+
+func TestView_EmptyStates(t *testing.T) {
+	m := sized()
+	m.loading = false
+	mustContain(t, m.View(), "No open incidents.")
+
+	m.activeSection = sectionArchived
+	mustContain(t, m.View(), "No archived incidents.")
+}
+
+func TestView_ConnectionError(t *testing.T) {
+	m := sized()
+	m.connected = false
+	m.err = errFixture{}
+	mustContain(t, m.View(), "Error:", "Press r to retry")
+}
+
+// The footer is the only place the terminal states are explained, so the
+// destructive one has to be visible before it is pressed.
+func TestFooter_IncidentDetailOffersResolveOnlyWhileOpen(t *testing.T) {
+	open := onIncident(openIncidentFixture(), nil)
+	mustContain(t, open.renderFooter(), "R·resolve", "z·snooze", "a·ack")
+
+	closed := onIncident(resolvedIncidentFixture(), nil)
+	if strings.Contains(plain(closed.renderFooter()), "R·resolve") {
+		t.Error("a resolved incident should not offer resolve")
+	}
+	mustContain(t, closed.renderFooter(), "x·archive", "c·note")
+}
+
+func TestView_ZeroWidthRendersNothing(t *testing.T) {
+	m := NewModel(nil, "http://test", time.Minute)
+	if m.View() != "" {
+		t.Error("expected no output before the first window size message")
+	}
+}
+
+type errFixture struct{}
+
+func (errFixture) Error() string { return "connection refused" }