(#) Visible Only For Tests !!! WARNING: Visible Only For Tests This is a warning. Id : `VisibleForTests` Summary : Visible Only For Tests Severity : Warning Category : Correctness Platform : Any Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 3.1.0 (March 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/RestrictToDetector.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/RestrictToDetectorTest.kt) This check looks for accesses from production code (e.g. not tests) where the access would not have been allowed with the intended production visibility. Depending on your development environment, you may be able to use an `@VisibleForTesting` annotation to specify the intended visibility if the method had not been more widely visible for the tests. When using `androidx.annotations.VisibleForTesting`, the production visibility is assumed to be private unless specified with the `otherwise=` parameter. `com.google.common.annotations.VisibleForTesting` and `com.android.internal.annotations.VisibleForTesting` work similarly with their own parameters called `productionVisibility` and `visibility`. If instead you use `org.jetbrains.annotations.VisibleForTesting`, there is no such parameter, and the production visibility is instead assumed to be "one step down" from the testing visibility. For example, if the testing visibility is public, the production visibility is assumed to be package-private. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text src/Code.kt:3:Warning: This method should only be accessed from tests or within private scope [VisibleForTests] ProductionCode().initialize() // Not allowed; this method is intended to be private ---------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here are the relevant source files: `src/ProductionCode.kt`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers import androidx.annotation.VisibleForTesting class ProductionCode { fun compute() { initialize() // OK } @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE) fun initialize() { } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ `src/Code.kt`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~kotlin linenumbers class Code { fun test() { ProductionCode().initialize() // Not allowed; this method is intended to be private } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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/RestrictToDetectorTest.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, `RestrictToDetector.testDocumentationExampleVisibleForTesting`. 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("VisibleForTests") fun method() { problematicStatement() } ``` or ```java // Java @SuppressWarnings("VisibleForTests") void method() { problematicStatement(); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection VisibleForTests 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="VisibleForTests" 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 'VisibleForTests' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore VisibleForTests ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).