Fix postinstall failing on windows (#770)

Change from executing a script on postinstall to invoking the cache
warmup via `node lib/warmup.js`.

This also improves logging during postinstall.

packages/optimizer/lib/fetchRuntimeParameters.js

@@ -79,8 +79,8 @@ async function fetchValidatorRules_(config) {
   let rawRules = await cache.get('validator-rules');
   let validatorRules;
   if (!rawRules) {
-    config.log.debug('Downloading AMP validation rules');
     validatorRules = await validatorRulesProvider.fetch();
+    config.log.debug('Downloaded AMP validation rules');
     // We save the raw rules to make the validation rules JSON serializable
     cache.set(KEY_VALIDATOR_RULES, validatorRules.raw);
   } else {
@@ -136,8 +136,8 @@ async function fetchAmpRuntimeVersion_(context) {
   const versionKey = context.ampUrlPrefix + '-' + context.lts;
   let ampRuntimeData = await cache.get(versionKey);
   if (!ampRuntimeData) {
-    context.config.log.debug('Downloading AMP runtime version');
     ampRuntimeData = await fetchLatestRuntimeData_(context, versionKey);
+    context.config.log.debug('Downloaded AMP runtime v' + ampRuntimeData.version);
   } else if (MaxAge.fromObject(ampRuntimeData.maxAge).isExpired()) {
     // return the cached version, but update the cache in the background
     fetchLatestRuntimeData_(versionKey, context);
@@ -197,12 +197,12 @@ async function downloadAmpRuntimeStyles_(config, runtimeCssUrl) {
     styles = await cache.get(runtimeCssUrl);
   }
   if (!styles) {
-    config.log.debug(`Downloading AMP runtime styles from ${runtimeCssUrl}`);
     const response = await config.fetch(runtimeCssUrl);
     if (!response.ok) {
       return null;
     }
     styles = await response.text();
+    config.log.debug(`Downloaded AMP runtime styles from ${runtimeCssUrl}`);
     if (config.cache !== false) {
       cache.set(runtimeCssUrl, styles);
     }

packages/optimizer/lib/transformers/PreloadHeroImage.js

@@ -35,7 +35,6 @@ class PreloadHeroImage {
   constructor(config) {
     this.log = config.log;
     this.enabled = config.preloadHeroImage !== false && config.experimentPreloadHeroImage;
-    this.log.info('enabled', this.enabled);
   }
   async transform(root, params) {
     if (!this.enabled || params.preloadHeroImage === false) {

packages/optimizer/lib/warmup.js

@@ -0,0 +1,28 @@
+/**
+ * Copyright 2020 The AMP HTML Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const AmpOptimizer = require('../');
+const ampOptimizer = AmpOptimizer.create();
+
+async function warmupCaches() {
+  // run a dummy transformation to pre-fill the caches
+  await ampOptimizer.transformHtml('<h1>hello world</h1>', {
+    canonical: '.',
+  });
+  ampOptimizer.config.log.info('Downloading latest AMP runtime data');
+}
+
+warmupCaches();

packages/optimizer/package.json

@@ -9,12 +9,11 @@
     "directory": "packages/optimizer"
   },
   "scripts": {
-    "postinstall": "scripts/init.js"
+    "postinstall": "node lib/warmup.js"
   },
   "files": [
     "index.js",
-    "lib",
-    "scripts"
+    "lib"
   ],
   "keywords": [
     "amp"