Support SpiderMonkey Nightly builds

Previously when requesting "latest" for SpiderMonkey, only the latest
available Beta version of SpiderMonkey was installed. Using the buildhub2 API
we can determine the latest Nightly version. Nightly binaries are available
under "https://archive.mozilla.org/pub/firefox/nightly/latest-mozilla-central".

src/engines/spidermonkey.js

@@ -32,23 +32,42 @@ class SpiderMonkeyInstaller extends Installer {
 
   static async resolveVersion(version) {
     if (version === 'latest') {
-      const data = await fetch('https://product-details.mozilla.org/1.0/firefox_history_development_releases.json')
-        .then((r) => r.json());
-      let latestVersion = 0;
-      let latestTimestamp = 0;
-      for (const [key, value] of Object.entries(data)) {
-        const timestamp = +new Date(value);
-        if (latestTimestamp < timestamp) {
-          latestTimestamp = timestamp;
-          latestVersion = key;
-        }
-      }
-      return latestVersion;
+      // Build a request for buildhub2: https://buildhub2.readthedocs.io/en/latest/project.html
+      const body = {
+        size: 1,
+        sort: { 'build.id': 'desc' },
+        query: {
+          bool: {
+            must: [
+              { term: { 'source.product': 'firefox' } },
+              { term: { 'source.tree': 'mozilla-central' } },
+              { term: { 'target.channel': 'nightly' } },
+              { term: { 'target.platform': getFilename() } },
+            ],
+          },
+        },
+      };
+
+      const data = await fetch('https://buildhub.moz.tools/api/search', {
+        method: 'post',
+        body: JSON.stringify(body),
+      }).then((r) => r.json());
+
+      const source = data.hits.hits[0]._source;
+
+      return `${source.target.version}#${source.build.id}`;
     }
     return version;
   }
 
   getDownloadURL(version) {
+    const match = /#(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})$/.exec(version);
+    if (match) {
+      const year = match[1];
+      const month = match[2];
+      const date = match.slice(1).join('-');
+      return `https://archive.mozilla.org/pub/firefox/nightly/${year}/${month}/${date}-mozilla-central/jsshell-${getFilename()}.zip`;
+    }
     return `https://archive.mozilla.org/pub/firefox/releases/${version}/jsshell/jsshell-${getFilename()}.zip`;
   }