improved config.json error handling, including additional tests (ref. #48)

service-worker.js

@@ -195,6 +195,11 @@ self.guessMimeType = async function(ext, content) {
  * cdata - config data to verify
  */
 let verifyConfigData = (cdata) => {
+    // cdata needs to be an object
+    if ( typeof cdata !== "object" || cdata === null ) {
+        self.log('service-worker', 'fetched config does not contain a valid JSON object')
+        return false;
+    }    
     // basic check for the plugins field
     if ( !("plugins" in cdata) || ! Array.isArray(cdata.plugins) ) {
         self.log('service-worker', 'fetched config does not contain a valid "plugins" field')
@@ -284,9 +289,6 @@ let executeConfig = (config) => {
     // in case we need it later (for example, when re-loading the config)
     let pluginsConfig = [...config.plugins]
         
-    // we want to catch any and all possible errors here
-    try {
-        
     // this is the stash for plugins that need dependencies instantiated first
     let dependentPlugins = new Array()
     
@@ -406,17 +408,6 @@ let executeConfig = (config) => {
     // we're good!
     return true;
     
-    // exception? no bueno
-    } catch (e) {
-        // inform
-        self.log('service-worker', `error while executing config: ${e.message}`)
-        // cleanup after a failed config execution
-        self.LibResilientPluginConstructors = new Map(lrpcBackup)
-        self.LibResilientPlugins = new Array()
-        // we are not good
-        return false;
-    }
-    
 }
 
 
@@ -530,8 +521,21 @@ let initServiceWorker = async () => {
             config = {...self.LibResilientConfig, ...cdata}
         
             // try executing the config
+            // we want to catch any and all possible errors here
+            try {
                 config_executed = executeConfig(config)
                 
+            // exception? no bueno
+            } catch (e) {
+                // inform
+                self.log('service-worker', `error while executing config: ${e.message}`)
+                // cleanup after a failed config execution
+                self.LibResilientPluginConstructors = new Map(lrpcBackup)
+                self.LibResilientPlugins = new Array()
+                // we are not good
+                config_executed = false;
+            }
+            
             // if we're using the defaults, and yet loading of the config failed
             // something is massively wrong
             if ( ( cresponse === false ) && ( config_executed === false ) ) {
@@ -552,15 +556,22 @@ let initServiceWorker = async () => {
         // that is, if it comes from the "v1" cache...
         if (use_cache === "v1") {
             self.log('service-worker', `successfully loaded config.json; caching in cache: v1:verified`)
-            cacheConfigJSON(configURL, cresponse, 'v1:verified')
-        // or, was fetch()ed and valid (no caching if we're going with defaults, obviously)
+            await cacheConfigJSON(configURL, cresponse, 'v1:verified')
+            
+        // we used the v1:verified cache; we should cache config.json into the v1 cache
+        // as that will speed things up a bit next time we need to load the service worker
+        } else if (use_cache === "v1:verified") {
+            self.log('service-worker', `successfully loaded config.json; caching in cache: v1`)
+            await cacheConfigJSON(configURL, cresponse, 'v1')
+        
+        // or, was fetch()-ed and valid (no caching if we're going with defaults, obviously)
         } else if ( (use_cache === undefined) && (cresponse !== false) ) {
             self.log('service-worker', `successfully loaded config.json; caching in cache: v1, v1:verified`)
             // we want to cache to both, so that:
             // 1. we get the extra bit of performance from using the v1 cache that is checked first
             // 2. but we get the verified config already in the v1:verified cache for later
-            cacheConfigJSON(configURL, await cresponse.clone(), 'v1')
-            cacheConfigJSON(configURL, cresponse, 'v1:verified')
+            await cacheConfigJSON(configURL, await cresponse.clone(), 'v1')
+            await cacheConfigJSON(configURL, cresponse, 'v1:verified')
         }
         
         // inform