From b8bb3b48e548a404dcbae55acc4d6e1ff57381c3 Mon Sep 17 00:00:00 2001
From: castrojo <castrojo@users.noreply.github.com>
Date: Tue, 8 Sep 2026 14:55:12 +0000
Subject: [PATCH] fix(factory): render an unavailable change-failure rate
 instead of 0.0%
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pct() multiplied null by 100, so a missing changeFailureRate from
fetch-dora.js (deliberately null when no terminal runs exist) rendered
as a misleading 0.0%. pct() now treats null/undefined/non-finite
inputs as unavailable and renders "—", reserving 0.0% for real
measured values.

Fixes projectbluefin/documentation#1091

Signed-off-by: castrojo <castrojo@users.noreply.github.com>
---
 scripts/metrics-panels.test.js                  | 15 +++++++++++++++
 src/components/factory/panels/MetricsPanels.tsx |  5 +++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/scripts/metrics-panels.test.js b/scripts/metrics-panels.test.js
index 1ab95ca85..f0b4c5fea 100644
--- a/scripts/metrics-panels.test.js
+++ b/scripts/metrics-panels.test.js
@@ -436,6 +436,21 @@ function render(fixtures) {
 
 // ── Tests ──────────────────────────────────────────────────────────────────
 
+test("null change failure rate renders unavailable marker, never 0.0%", () => {
+  const doraNullRate = {
+    ...DORA,
+    current: { ...DORA.current, changeFailureRate: null },
+  };
+  const html = render({
+    countme: COUNTME_FULL,
+    brew: BREW,
+    dora: doraNullRate,
+    scorecard: SCORECARD,
+  });
+  assert.ok(!html.includes("0.0%"));
+  assert.ok(html.includes("—"));
+});
+
 test("lead time renders as not-measured, never as 0", () => {
   const html = render({
     countme: COUNTME_FULL,
diff --git a/src/components/factory/panels/MetricsPanels.tsx b/src/components/factory/panels/MetricsPanels.tsx
index cd122472f..618685b4d 100644
--- a/src/components/factory/panels/MetricsPanels.tsx
+++ b/src/components/factory/panels/MetricsPanels.tsx
@@ -61,7 +61,7 @@ interface DoraMonthly {
 }
 interface DoraCurrent {
   deploymentsPerWeek: number;
-  changeFailureRate: number;
+  changeFailureRate: number | null;
   medianLeadTimeHours: number | null;
   leadTimeReason?: string;
 }
@@ -113,7 +113,8 @@ function fmt(n: number | null | undefined): string {
   return n.toLocaleString("en-US");
 }
 
-function pct(n: number): string {
+function pct(n: number | null | undefined): string {
+  if (n == null || !Number.isFinite(n)) return "—";
   return `${(n * 100).toFixed(1)}%`;
 }