Improved cache purging.

server/index.js

@@ -138,6 +138,7 @@ async function handlePurgeRequest(req, res) {
     if (method === 'regex' && url === '/.*') {
         pageDependencies = {};
         await NginxCache.purge(/.*/);
+        await PageRenderer.prefetch('/');
     } else if (method === 'default') {
         // look for URLs that looks like /wp-json/wp/v2/pages/4/
         let m = /^\/wp\-json\/(\w+\/\w+\/\w+)\/(\d+)\/$/.exec(url);
@@ -148,11 +149,7 @@ async function handlePurgeRequest(req, res) {
         // purge matching JSON files
         let folderPath = m[1];
         let pattern = new RegExp(`^/json/${folderPath}.*`);
-        let purgedURLs = await NginxCache.purge(pattern);
-        if (purgedURLs.length === 0) {
-            return;
-        }
-        purgedURLs = purgedURLs.map(addTrailingSlash);
+        await NginxCache.purge(pattern);
 
         // purge the timestamp so CSR code knows something has changed
         await NginxCache.purge('/.mtime');
@@ -160,16 +157,19 @@ async function handlePurgeRequest(req, res) {
         // look for pages that made use of the purged JSONs
         for (let [ path, sourceURLs ] of Object.entries(pageDependencies)) {
             let affected = sourceURLs.some((sourceURL) => {
-                return purgedURLs.indexOf(sourceURL) !== -1;
+                return pattern.test(sourceURL);
             });
             if (affected) {
                 // purge the cached page
                 await NginxCache.purge(path);
                 delete pageDependencies[path];
+
+                if (path === '/') {
+                    await PageRenderer.prefetch('/');
+                }
             }
         }
     }
-    await PageRenderer.prefetch('/');
 }
 
 function handleError(err, req, res, next) {