Merge "Prefer Executor injection" into tm-qpr-dev

packages/SystemUI/checks/src/com/android/internal/systemui/lint/GetMainLooperViaContextDetector.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.systemui.lint
+
+import com.android.tools.lint.detector.api.Category
+import com.android.tools.lint.detector.api.Detector
+import com.android.tools.lint.detector.api.Implementation
+import com.android.tools.lint.detector.api.Issue
+import com.android.tools.lint.detector.api.JavaContext
+import com.android.tools.lint.detector.api.Scope
+import com.android.tools.lint.detector.api.Severity
+import com.android.tools.lint.detector.api.SourceCodeScanner
+import com.intellij.psi.PsiMethod
+import org.jetbrains.uast.UCallExpression
+
+@Suppress("UnstableApiUsage")
+class GetMainLooperViaContextDetector : Detector(), SourceCodeScanner {
+
+    override fun getApplicableMethodNames(): List<String> {
+        return listOf("getMainThreadHandler", "getMainLooper", "getMainExecutor")
+    }
+
+    override fun visitMethodCall(context: JavaContext, node: UCallExpression, method: PsiMethod) {
+        if (context.evaluator.isMemberInSubClassOf(method, "android.content.Context")) {
+            context.report(
+                    ISSUE,
+                    method,
+                    context.getNameLocation(node),
+                    "Please inject a @Main Executor instead."
+            )
+        }
+    }
+
+    companion object {
+        @JvmField
+        val ISSUE: Issue =
+                Issue.create(
+                        id = "GetMainLooperViaContextDetector",
+                        briefDescription = "Please use idiomatic SystemUI executors, injecting " +
+                                "them via Dagger.",
+                        explanation = "Injecting the @Main Executor is preferred in order to make" +
+                                "dependencies explicit and increase testability. It's much " +
+                                "easier to pass a FakeExecutor on your test ctor than to " +
+                                "deal with loopers in unit tests.",
+                        category = Category.LINT,
+                        priority = 8,
+                        severity = Severity.WARNING,
+                        implementation = Implementation(GetMainLooperViaContextDetector::class.java,
+                                Scope.JAVA_FILE_SCOPE)
+                )
+    }
+}

packages/SystemUI/checks/src/com/android/internal/systemui/lint/SystemUIIssueRegistry.kt

@@ -29,6 +29,7 @@ class SystemUIIssueRegistry : IssueRegistry() {
     override val issues: List<Issue>
         get() = listOf(BindServiceViaContextDetector.ISSUE,
                 BroadcastSentViaContextDetector.ISSUE,
+                GetMainLooperViaContextDetector.ISSUE,
                 RegisterReceiverViaContextDetector.ISSUE
         )
 

packages/SystemUI/checks/tests/com/android/systemui/lint/GetMainLooperViaContextDetectorTest.kt

@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.systemui.lint
+
+import com.android.tools.lint.checks.infrastructure.LintDetectorTest
+import com.android.tools.lint.checks.infrastructure.TestFile
+import com.android.tools.lint.checks.infrastructure.TestFiles
+import com.android.tools.lint.checks.infrastructure.TestLintTask
+import com.android.tools.lint.detector.api.Detector
+import com.android.tools.lint.detector.api.Issue
+import org.junit.Test
+
+class GetMainLooperViaContextDetectorTest : LintDetectorTest() {
+
+    override fun getDetector(): Detector = GetMainLooperViaContextDetector()
+    override fun lint(): TestLintTask = super.lint().allowMissingSdk(true)
+
+    override fun getIssues(): List<Issue> = listOf(GetMainLooperViaContextDetector.ISSUE)
+
+    private val explanation = "Please inject a @Main Executor instead."
+
+    @Test
+    fun testGetMainThreadHandler() {
+        lint().files(
+                TestFiles.java(
+                        """
+                    package test.pkg;
+                    import android.content.Context;
+                    import android.os.Handler;
+
+                    public class TestClass1 {
+                        public void test(Context context) {
+                          Handler mainThreadHandler = context.getMainThreadHandler();
+                        }
+                    }
+                """
+                ).indented(),
+                *stubs)
+                .issues(GetMainLooperViaContextDetector.ISSUE)
+                .run()
+                .expectWarningCount(1)
+                .expectContains(explanation)
+    }
+
+    @Test
+    fun testGetMainLooper() {
+        lint().files(
+                TestFiles.java(
+                        """
+                    package test.pkg;
+                    import android.content.Context;
+                    import android.os.Looper;
+
+                    public class TestClass1 {
+                        public void test(Context context) {
+                          Looper mainLooper = context.getMainLooper();
+                        }
+                    }
+                """
+                ).indented(),
+                *stubs)
+                .issues(GetMainLooperViaContextDetector.ISSUE)
+                .run()
+                .expectWarningCount(1)
+                .expectContains(explanation)
+    }
+
+    @Test
+    fun testGetMainExecutor() {
+        lint().files(
+                TestFiles.java(
+                        """
+                    package test.pkg;
+                    import android.content.Context;
+                    import java.util.concurrent.Executor;
+
+                    public class TestClass1 {
+                        public void test(Context context) {
+                          Executor mainExecutor = context.getMainExecutor();
+                        }
+                    }
+                """
+                ).indented(),
+                *stubs)
+                .issues(GetMainLooperViaContextDetector.ISSUE)
+                .run()
+                .expectWarningCount(1)
+                .expectContains(explanation)
+    }
+
+    private val contextStub: TestFile = java(
+            """
+        package android.content;
+        import android.os.Handler;import android.os.Looper;import java.util.concurrent.Executor;
+
+        public class Context {
+            public Looper getMainLooper() { return null; };
+            public Executor getMainExecutor() { return null; };
+            public Handler getMainThreadHandler() { return null; };
+        }
+        """
+    )
+
+    private val looperStub: TestFile = java(
+            """
+        package android.os;
+
+        public class Looper {}
+        """
+    )
+
+    private val handlerStub: TestFile = java(
+            """
+        package android.os;
+
+        public class Handler {}
+        """
+    )
+
+    private val stubs = arrayOf(contextStub, looperStub, handlerStub)
+}