Move maxRecoverableFailures to Policy class

Author: brizental

glean/src/core/upload/index.ts

@@ -23,6 +23,10 @@ const LOG_TAG = "core.Upload";
  */
 export class Policy {
   constructor (
+    // The maximum recoverable failures allowed per uploading window.
+    //
+    // Limiting this is necessary to avoid infinite loops on requesting upload tasks.
+    readonly maxRecoverableFailures: number = 3,
     // The maximum size in bytes a ping body may have to be eligible for upload.
     readonly maxPingBodySize: number = 1024 * 1024 // 1MB
   ) {}
@@ -289,7 +293,7 @@ class PingUploader implements PingsDatabaseObserver {
         this.enqueuePing(nextPing);
       }
 
-      if (retries >= 3) {
+      if (retries >= this.policy.maxRecoverableFailures) {
         log(
           LOG_TAG,
           "Reached maximum recoverable failures for the current uploading window. You are done.",

glean/tests/unit/core/upload/index.spec.ts

@@ -195,9 +195,23 @@ describe("PingUploader", function() {
       status: 500,
       result: UploadResultStatus.Success
     }));
+
+    // Create a new ping uploader with a fixed max recoverable failures limit.
+    const uploader = new PingUploader(
+      new Configuration(),
+      Glean.platform,
+      Context.pingsDatabase,
+      new Policy(
+        3, // maxRecoverableFailures
+      )
+    );
+
+    // Overwrite the Glean ping uploader with the test one.
+    Context.pingsDatabase.attachObserver(uploader);
+
     await fillUpPingsDatabase(1);
+    await waitForUploader(uploader);
 
-    await waitForUploader();
     assert.strictEqual(stub.callCount, 3);
   });