From a127109c3f8f62a0c0a4a5ae5ae82e00c33782c1 Mon Sep 17 00:00:00 2001
From: Sam Sneddon <gsnedders@apple.com>
Date: Wed, 10 Aug 2022 00:00:48 +0100
Subject: [PATCH] Avoid caching the last few days in case new runs appear

This regressed with #87, but it doesn't occur in CI as we never have a
populated cache when this is run.
---
 lib/runs.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/runs.js b/lib/runs.js
index 737212254..c8835b8f0 100644
--- a/lib/runs.js
+++ b/lib/runs.js
@@ -89,6 +89,7 @@ async function fetchAlignedRunsFromServer(products, from, to, experimental) {
 
   let cachedCount = 0;
   const before = moment();
+  const noCacheAfter = moment().sub('3', 'days');
   const alignedRuns = new Map();
   while (from < to) {
     const formattedFrom = from.format('YYYY-MM-DD');
@@ -113,10 +114,14 @@ async function fetchAlignedRunsFromServer(products, from, to, experimental) {
       // No cache hit; load from the server instead.
       const url = `${runsUri}&from=${formattedFrom}&to=${formattedTo}`;
       const response = await fetch(url);
-      // Many days do not have an aligned set of runs, but we always write to
-      // the cache to speed up future executions of this code.
       runs = await response.json();
-      await fs.promises.writeFile(cacheFile, JSON.stringify(runs));
+
+      if (from.isSameOrBefore(noCacheAfter)) {
+        // Avoid caching for the last few days, as new runs may still appear
+        // here; otherwise, cache unconditionally, even if we do not have an
+        // aligned set of runs.
+        await fs.promises.writeFile(cacheFile, JSON.stringify(runs));
+      }
     }
 
     if (!runs.length) {