(#) WorkManager Enqueue !!! WARNING: WorkManager Enqueue This is a warning. Id : `EnqueueWork` Summary : WorkManager Enqueue Severity : Warning Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 3.2.0 (September 2018) Affects : Kotlin and Java files Editing : This check runs on the fly in the IDE editor Implementation : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/WorkManagerDetector.kt) Tests : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/WorkManagerDetectorTest.kt) `WorkContinuations` cannot be enqueued automatically. You must call `enqueue()` on a `WorkContinuation` to have it and its parent continuations enqueued inside `WorkManager`. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text src/test/pkg/WorkManagerTest.java:15:Warning: WorkContinuation cont not enqueued: did you forget to call enqueue()? [EnqueueWork] WorkContinuation cont = workManager.beginWith(workRequest1, workRequest2); // ERROR ------------------------------------------------- src/test/pkg/WorkManagerTest.java:22:Warning: WorkContinuation not enqueued: did you forget to call enqueue()? [EnqueueWork] workManager.beginWith(workRequest1, workRequest2); // ERROR ------------------------------------------------- src/test/pkg/WorkManagerTest.java:46:Warning: WorkContinuation cont2 not enqueued: did you forget to call enqueue()? [EnqueueWork] WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // ERROR ------------------------------------------- src/test/pkg/WorkManagerTest.java:47:Warning: WorkContinuation cont3 not enqueued: did you forget to call enqueue()? [EnqueueWork] WorkContinuation cont3 = cont1.then(workRequest5); // ERROR ------------------------ src/test/pkg/WorkManagerTest.java:59:Warning: WorkContinuation cont4 not enqueued: did you forget to call enqueue()? [EnqueueWork] WorkContinuation cont4 = WorkContinuation.combine(workRequest6, cont2, cont3); // ERROR ---------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `src/test/pkg/WorkManagerTest.java`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers package test.pkg; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import androidx.work.WorkManager; import androidx.work.WorkContinuation; import androidx.work.OneTimeWorkRequest;import java.util.Arrays; @SuppressWarnings({"ClassNameDiffersFromFileName", "unused"}) public abstract class WorkManagerTest { void someWork(OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont = workManager.beginWith(workRequest1, workRequest2); // ERROR doSomeOtherStuff(); // cont needs to be enqueued before it goes out of scope } void someWork2(OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2) { WorkManager workManager = WorkManager.getInstance(); workManager.beginWith(workRequest1, workRequest2); // ERROR doSomeOtherStuff(); } void someWork3(OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont = workManager.beginWith(workRequest1, workRequest2); // OK doSomeOtherStuff(); cont.enqueue(); } void someWork4(OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont = workManager.beginWith(workRequest1, workRequest2).enqueue(); // OK doSomeOtherStuff(); cont.enqueue(); } void someHarderWork( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2, OneTimeWorkRequest workRequest3, OneTimeWorkRequest workRequest4, OneTimeWorkRequest workRequest5) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // ERROR WorkContinuation cont3 = cont1.then(workRequest5); // ERROR // cont2 and cont3 need to be enqueued before they go out of scope; cont1 does not } void someEvenHarderWork( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2, OneTimeWorkRequest workRequest3, OneTimeWorkRequest workRequest4, OneTimeWorkRequest workRequest5, OneTimeWorkRequest workRequest6) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // OK WorkContinuation cont3 = cont1.then(workRequest5); // OK WorkContinuation cont4 = WorkContinuation.combine(workRequest6, cont2, cont3); // ERROR // Only cont4 needs to be enqueued } void someEvenHarderWorkDoneProperly( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2, OneTimeWorkRequest workRequest3, OneTimeWorkRequest workRequest4, OneTimeWorkRequest workRequest5, OneTimeWorkRequest workRequest6) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // OK WorkContinuation cont3 = cont1.then(workRequest5); // OK WorkContinuation cont4 = WorkContinuation.combine(workRequest6, cont2, cont3); // OK cont4.enqueue(); } void someEvenHarderWorkWithLists1( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2, OneTimeWorkRequest workRequest3, OneTimeWorkRequest workRequest4, OneTimeWorkRequest workRequest5, OneTimeWorkRequest workRequest6) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // OK WorkContinuation cont3 = cont1.then(workRequest5); // OK List continuations = new ArrayList<>(); continuations.add(cont2); continuations.add(cont3); WorkContinuation cont4 = WorkContinuation.combine(workRequest6, continuations); // OK cont4.enqueue(); } void someEvenHarderWorkWithLists2( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2, OneTimeWorkRequest workRequest3, OneTimeWorkRequest workRequest4, OneTimeWorkRequest workRequest5, OneTimeWorkRequest workRequest6) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK WorkContinuation cont2 = cont1.then(workRequest3).then(workRequest4); // OK WorkContinuation cont3 = cont1.then(workRequest5); // OK List continuations = Arrays.asList(cont2, cont3); WorkContinuation cont4 = WorkContinuation.combine(workRequest6, continuations); // OK cont4.enqueue(); } WorkContinuation someWorkThatIsReturned( OneTimeWorkRequest workRequest1, OneTimeWorkRequest workRequest2) { WorkManager workManager = WorkManager.getInstance(); WorkContinuation cont1 = workManager.beginWith(workRequest1, workRequest2); // OK return cont1; } private void doSomeOtherStuff() { } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/WorkManagerDetectorTest.kt) for the unit tests for this check to see additional scenarios. The above example was automatically extracted from the first unit test found for this lint check, `WorkManagerDetector.testJava`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=192708. (##) Suppressing You can suppress false positives using one of the following mechanisms: * Using a suppression annotation like this on the enclosing element: ```kt // Kotlin @Suppress("EnqueueWork") fun method() { beginWith(...) } ``` or ```java // Java @SuppressWarnings("EnqueueWork") void method() { beginWith(...); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection EnqueueWork problematicStatement() ``` * Using a special `lint.xml` file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this: ```xml <?xml version="1.0" encoding="UTF-8"?> <lint> <issue id="EnqueueWork" severity="ignore" /> </lint> ``` Instead of `ignore` you can also change the severity here, for example from `error` to `warning`. You can find additional documentation on how to filter issues by path, regular expression and so on [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html). * In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like ```gradle lintOptions { disable 'EnqueueWork' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore EnqueueWork ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).