fix: don't revive lazy deletes even if the OS wants to

src/index.ts

@@ -239,7 +239,7 @@ export default class DownloadQueue {
     this.isPausedByUser = !startActive;
 
     // First revive tasks that were working in the background
-    existingTasks.forEach(task => this.reviveTask(task));
+    await Promise.all(existingTasks.map(task => this.reviveTask(task)));
 
     // Now start downloads for specs that haven't finished
     const specsToDownload = this.specs.filter(
@@ -731,9 +731,12 @@ export default class DownloadQueue {
     }
   }
 
-  private reviveTask(task: DownloadTask) {
+  private async reviveTask(task: DownloadTask) {
     const spec = this.specs.find(spec => spec.id === task.id);
-    if (spec) {
+
+    // Don't revive finished tasks or ones that already have lazy deletes in
+    // progress.
+    if (spec && !spec.finished && spec.createTime > 0) {
       let shouldAddTask = true;
 
       switch (task.state) {
@@ -778,6 +781,18 @@ export default class DownloadQueue {
     } else {
       if (["DOWNLOADING", "PAUSED"].includes(task.state)) {
         task.stop();
+
+        if (spec && !spec.finished) {
+          try {
+            // There might be a partially downloaded file on disk. We need to
+            // get rid of it in case a lazy-delete spec is revived, at which
+            // point an existing file on disk will be taken to be a
+            // successfully downloaded one.
+            await RNFS.unlink(spec.path);
+          } catch {
+            // Expected for missing files
+          }
+        }
       }
     }
   }

test/index.spec.ts

@@ -439,6 +439,25 @@ describe("DownloadQueue", () => {
       expect(task.stop).toHaveBeenCalledTimes(2);
     });
 
+    it("stops lazy-deleted tasks from previous launches", async () => {
+      const queue = new DownloadQueue();
+
+      (checkForExistingDownloads as jest.Mock).mockReturnValue([task]);
+      await kvfs.write("/mydomain/foo", {
+        id: task.id,
+        url: "http://foo.com/a.mp3",
+        path: `${RNFS.DocumentDirectoryPath}/DownloadQueue/mydomain/foo`,
+        createTime: -(Date.now() + 300000), // simulate lazy-delete
+      });
+
+      task.state = "DOWNLOADING";
+      await queue.init({ domain: "mydomain" });
+
+      expect(task.stop).toHaveBeenCalledTimes(1);
+      // Should also delete partially-downloaded file
+      expect(unlink).toHaveBeenCalledTimes(1);
+    });
+
     it("starts downloads for specs without tasks or files", async () => {
       const queue = new DownloadQueue();
 
@@ -1652,7 +1671,7 @@ describe("DownloadQueue", () => {
     it("should handle a case where spec is finished but file is missing", async () => {
       const queue = new DownloadQueue();
 
-      (download as jest.Mock).mockImplementation(_ =>
+      (download as jest.Mock).mockImplementation(() =>
         Object.assign(task, {
           done: jest.fn((handler: DoneHandler) => {
             task._done = handler;
@@ -1676,7 +1695,7 @@ describe("DownloadQueue", () => {
       Platform.OS = "android";
       const queue = new DownloadQueue();
 
-      (download as jest.Mock).mockImplementation(_ =>
+      (download as jest.Mock).mockImplementation(() =>
         Object.assign(task, {
           done: jest.fn((handler: DoneHandler) => {
             task._done = handler;