LibResilientResourceInfo can now hold errors for all plugins (ref. #36)

service-worker.js

@@ -883,12 +883,14 @@ let LibResilientResourceInfo = class {
         this.values = {
             url: '',                        // read only after initialization
             clientId: null,                 // the client on whose behalf that request is being processed    
-            lastError: null,                // error from the previous plugin (for state:running) or the last emitted error (for state:failed or state:success)
             method: null,                   // name of the current plugin (in case of state:running) or last plugin (for state:failed or state:success)
             state: null,                    // can be "failed", "success", "running"
             serviceWorker: 'COMMIT_UNKNOWN' // this will be replaced by commit sha in CI/CD; read-only
         }
         
+        // errors from the plugins, contains tuples: [plugin-name, exception-or-response-object]
+        this.errors = []
+        
         // queued messages for when we have a client available
         this.messageQueue = []
         
@@ -915,11 +917,11 @@ let LibResilientResourceInfo = class {
         var msg = 'Updated LibResilientResourceInfo for: ' + this.values.url
         // was there a change? if not, no need to postMessage
         var changed = false
-        // update the properties that are read-write
+        // update simple read-write properties
         Object
             .keys(data)
             .filter((k)=>{
-                return ['lastError', 'method', 'state'].includes(k)
+                return ['method', 'state'].includes(k)
             })
             .forEach((k)=>{
                 msg += '\n+-- ' + k + ': ' + data[k]
@@ -929,23 +931,31 @@ let LibResilientResourceInfo = class {
                 }
                 this.values[k] = data[k]
             })
+        // start preparing the data to postMessage() over to the client
+        let msgdata = {...this.values}
+        // handle any error related info
+        if ('error' in data) {
+            // push the error info, along with method that generated it, onto the error stack
+            this.errors.push([this.values.method, data.error])
+            // response?
+            if ("statusText" in data.error) {
+                msgdata.error = `HTTP status: ${data.error.status} ${data.error.statusText}`
+            // nope, exception
+            } else {
+                msgdata.error = data.error.toString()
+            }
+            changed = true
+        }
         self.log('service-worker', msg)
         // send the message to the client
         if (changed) {
             postMessage(
                 this.values.clientId,
-                {...this.values}
+                msgdata
             );
         }
     }
 
-    /**
-     * lastError property
-     */
-    get lastError() {
-        return this.values.lastError
-    }
-
     /**
      * method property
      */
@@ -1129,7 +1139,7 @@ let getResourceThroughLibResilient = (url, init, clientId, useStashed=true, doSt
                                 '\n+-- error  : ' + error.toString())
                     // save info in reqInfo -- status of the previous method
                     reqInfo.update({
-                        lastError: error.toString()
+                        error: error
                     })
                     return libresilientFetch(currentPlugin, url, init, reqInfo)
                 })
@@ -1146,7 +1156,6 @@ let getResourceThroughLibResilient = (url, init, clientId, useStashed=true, doSt
             
             // record the success
             reqInfo.update({
-                lastError: null,
                 state:"success"
             })
             
@@ -1246,7 +1255,7 @@ let getResourceThroughLibResilient = (url, init, clientId, useStashed=true, doSt
             // cleanup
             reqInfo.update({
                 state: "failed",
-                lastError: err.toString()
+                error: err
             })
             decrementActiveFetches(clientId)
             // rethrow
@@ -1469,7 +1478,7 @@ self.addEventListener('fetch', async event => {
                                                     header.innerHTML = "Loading failed."
                                                     text.innerHTML = "We're sorry, we were unable to load this page."
                                                 } 
-                                                if ( ( 'lastError' in event.data ) && ( typeof event.data.lastError === 'string' ) ) {
+                                                if ( ( 'error' in event.data ) && ( typeof event.data.error === 'object' ) ) {
                                                     attempts += 1;
                                                     status.innerHTML = attempts;
                                                 }