SysUI linter: Clean Architecture Dependency Rule. (878ae084) · Commits · e / os / android_frameworks_base

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

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		/*
		* Copyright (C) 2023 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.client.api.UElementHandler
		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 org.jetbrains.uast.UElement
		import org.jetbrains.uast.UFile
		import org.jetbrains.uast.UImportStatement

		/**
		* Detects violations of the Dependency Rule of Clean Architecture.
		*
		* The rule states that code in each layer may only depend on code in the same layer or the layer
		* directly "beneath" that layer in the layer diagram.
		*
		* In System UI, we have three layers; from top to bottom, they are: ui, domain, and data. As a
		* convention, was used packages with those names to place code in the appropriate layer. We also
		* make an exception and allow for shared models to live under a separate package named "shared" to
		* avoid code duplication.
		*
		* For more information, please see go/sysui-arch.
		*/
		@Suppress("UnstableApiUsage")
		class CleanArchitectureDependencyViolationDetector : Detector(), Detector.UastScanner {
		override fun getApplicableUastTypes(): List<Class<out UElement>> {
		return listOf(UFile::class.java)
		}

		override fun createUastHandler(context: JavaContext): UElementHandler {
		return object : UElementHandler() {
		override fun visitFile(node: UFile) {
		// Check which Clean Architecture layer this file belongs to:
		matchingLayer(node.packageName)?.let { layer ->
		// The file matches with a Clean Architecture layer. Let's check all of its
		// imports.
		node.imports.forEach { importStatement ->
		visitImportStatement(context, layer, importStatement)
		}
		}
		}
		}
		}

		private fun visitImportStatement(
		context: JavaContext,
		layer: Layer,
		importStatement: UImportStatement,
		) {
		val importText = importStatement.importReference?.asSourceString() ?: return
		val importedLayer = matchingLayer(importText) ?: return

		// Now check whether the layer of the file may depend on the layer of the import.
		if (!layer.mayDependOn(importedLayer)) {
		context.report(
		issue = ISSUE,
		scope = importStatement,
		location = context.getLocation(importStatement),
		message =
		"The ${layer.packageNamePart} layer may not depend on" +
		" the ${importedLayer.packageNamePart} layer.",
		)
		}
		}

		private fun matchingLayer(packageName: String): Layer? {
		val packageNameParts = packageName.split(".").toSet()
		return Layer.values()
		.filter { layer -> packageNameParts.contains(layer.packageNamePart) }
		.takeIf { it.size == 1 }
		?.first()
		}

		private enum class Layer(
		val packageNamePart: String,
		val canDependOn: Set<Layer>,
		) {
		SHARED(
		packageNamePart = "shared",
		canDependOn = emptySet(), // The shared layer may not depend on any other layer.
		),
		DATA(
		packageNamePart = "data",
		canDependOn = setOf(SHARED),
		),
		DOMAIN(
		packageNamePart = "domain",
		canDependOn = setOf(SHARED, DATA),
		),
		UI(
		packageNamePart = "ui",
		canDependOn = setOf(DOMAIN, SHARED),
		),
		;

		fun mayDependOn(otherLayer: Layer): Boolean {
		return this == otherLayer \|\| canDependOn.contains(otherLayer)
		}
		}

		companion object {
		@JvmStatic
		val ISSUE =
		Issue.create(
		id = "CleanArchitectureDependencyViolation",
		briefDescription = "Violation of the Clean Architecture Dependency Rule.",
		explanation =
		"""
		Following the \"Dependency Rule\" from Clean Architecture, every layer of code \
		can only depend code in its own layer or code in the layer directly \
		\"beneath\" it. Therefore, the UI layer can only depend on the" Domain layer \
		and the Domain layer can only depend on the Data layer. We" do make an \
		exception to allow shared models to exist and be shared across layers by \
		placing them under shared/model, which should be done with care. For more \
		information about Clean Architecture in System UI, please see go/sysui-arch. \
		NOTE: if your code is not using Clean Architecture, please feel free to ignore \
		this warning.
		""",
		category = Category.CORRECTNESS,
		priority = 8,
		severity = Severity.WARNING,
		implementation =
		Implementation(
		CleanArchitectureDependencyViolationDetector::class.java,
		Scope.JAVA_FILE_SCOPE,
		),
		)
		}
		}

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

+9 −7

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		@@ -27,9 +27,11 @@ import com.google.auto.service.AutoService
		class SystemUIIssueRegistry : IssueRegistry() {

		override val issues: List<Issue>
		get() = listOf(
		get() =
		listOf(
		BindServiceOnMainThreadDetector.ISSUE,
		BroadcastSentViaContextDetector.ISSUE,
		CleanArchitectureDependencyViolationDetector.ISSUE,
		SlowUserQueryDetector.ISSUE_SLOW_USER_ID_QUERY,
		SlowUserQueryDetector.ISSUE_SLOW_USER_INFO_QUERY,
		NonInjectedMainThreadDetector.ISSUE,

packages/SystemUI/checks/tests/com/android/internal/systemui/lint/CleanArchitectureDependencyViolationDetectorTest.kt

0 → 100644

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		/*
		* Copyright (C) 2023 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.TestFiles
		import com.android.tools.lint.checks.infrastructure.TestMode
		import com.android.tools.lint.detector.api.Detector
		import com.android.tools.lint.detector.api.Issue
		import org.junit.Ignore
		import org.junit.Test

		@Suppress("UnstableApiUsage")
		@Ignore("b/254533331")
		class CleanArchitectureDependencyViolationDetectorTest : SystemUILintDetectorTest() {
		override fun getDetector(): Detector {
		return CleanArchitectureDependencyViolationDetector()
		}

		override fun getIssues(): List<Issue> {
		return listOf(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		}

		@Test
		fun `No violations`() {
		lint()
		.files(
		*LEGITIMATE_FILES,
		)
		.issues(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		.run()
		.expectWarningCount(0)
		}

		@Test
		fun `Violation - domain depends on ui`() {
		lint()
		.files(
		*LEGITIMATE_FILES,
		TestFiles.kotlin(
		"""
		package test.domain.interactor

		import test.ui.viewmodel.ViewModel

		class BadClass(
		private val viewModel: ViewModel,
		)
		""".trimIndent()
		)
		)
		.issues(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		.testModes(TestMode.DEFAULT)
		.run()
		.expectWarningCount(1)
		.expect(
		expectedText =
		"""
		src/test/domain/interactor/BadClass.kt:3: Warning: The domain layer may not depend on the ui layer. [CleanArchitectureDependencyViolation]
		import test.ui.viewmodel.ViewModel
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		0 errors, 1 warnings
		""",
		)
		}

		@Test
		fun `Violation - ui depends on data`() {
		lint()
		.files(
		*LEGITIMATE_FILES,
		TestFiles.kotlin(
		"""
		package test.ui.viewmodel

		import test.data.repository.Repository

		class BadClass(
		private val repository: Repository,
		)
		""".trimIndent()
		)
		)
		.issues(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		.testModes(TestMode.DEFAULT)
		.run()
		.expectWarningCount(1)
		.expect(
		expectedText =
		"""
		src/test/ui/viewmodel/BadClass.kt:3: Warning: The ui layer may not depend on the data layer. [CleanArchitectureDependencyViolation]
		import test.data.repository.Repository
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		0 errors, 1 warnings
		""",
		)
		}

		@Test
		fun `Violation - shared depends on all other layers`() {
		lint()
		.files(
		*LEGITIMATE_FILES,
		TestFiles.kotlin(
		"""
		package test.shared.model

		import test.data.repository.Repository
		import test.domain.interactor.Interactor
		import test.ui.viewmodel.ViewModel

		class BadClass(
		private val repository: Repository,
		private val interactor: Interactor,
		private val viewmodel: ViewModel,
		)
		""".trimIndent()
		)
		)
		.issues(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		.testModes(TestMode.DEFAULT)
		.run()
		.expectWarningCount(3)
		.expect(
		expectedText =
		"""
		src/test/shared/model/BadClass.kt:3: Warning: The shared layer may not depend on the data layer. [CleanArchitectureDependencyViolation]
		import test.data.repository.Repository
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		src/test/shared/model/BadClass.kt:4: Warning: The shared layer may not depend on the domain layer. [CleanArchitectureDependencyViolation]
		import test.domain.interactor.Interactor
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		src/test/shared/model/BadClass.kt:5: Warning: The shared layer may not depend on the ui layer. [CleanArchitectureDependencyViolation]
		import test.ui.viewmodel.ViewModel
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		0 errors, 3 warnings
		""",
		)
		}

		@Test
		fun `Violation - data depends on domain`() {
		lint()
		.files(
		*LEGITIMATE_FILES,
		TestFiles.kotlin(
		"""
		package test.data.repository

		import test.domain.interactor.Interactor

		class BadClass(
		private val interactor: Interactor,
		)
		""".trimIndent()
		)
		)
		.issues(
		CleanArchitectureDependencyViolationDetector.ISSUE,
		)
		.testModes(TestMode.DEFAULT)
		.run()
		.expectWarningCount(1)
		.expect(
		expectedText =
		"""
		src/test/data/repository/BadClass.kt:3: Warning: The data layer may not depend on the domain layer. [CleanArchitectureDependencyViolation]
		import test.domain.interactor.Interactor
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		0 errors, 1 warnings
		""",
		)
		}

		companion object {
		private val MODEL_FILE =
		TestFiles.kotlin(
		"""
		package test.shared.model

		import test.some.other.thing.SomeOtherThing

		data class Model(
		private val name: String,
		)
		""".trimIndent()
		)
		private val REPOSITORY_FILE =
		TestFiles.kotlin(
		"""
		package test.data.repository

		import test.shared.model.Model
		import test.some.other.thing.SomeOtherThing

		class Repository {
		private val models = listOf(
		Model("one"),
		Model("two"),
		Model("three"),
		)

		fun getModels(): List<Model> {
		return models
		}
		}
		""".trimIndent()
		)
		private val INTERACTOR_FILE =
		TestFiles.kotlin(
		"""
		package test.domain.interactor

		import test.data.repository.Repository
		import test.shared.model.Model

		class Interactor(
		private val repository: Repository,
		) {
		fun getModels(): List<Model> {
		return repository.getModels()
		}
		}
		""".trimIndent()
		)
		private val VIEW_MODEL_FILE =
		TestFiles.kotlin(
		"""
		package test.ui.viewmodel

		import test.domain.interactor.Interactor
		import test.some.other.thing.SomeOtherThing

		class ViewModel(
		private val interactor: Interactor,
		) {
		fun getNames(): List<String> {
		return interactor.getModels().map { model -> model.name }
		}
		}
		""".trimIndent()
		)
		private val NON_CLEAN_ARCHITECTURE_FILE =
		TestFiles.kotlin(
		"""
		package test.some.other.thing

		import test.data.repository.Repository
		import test.domain.interactor.Interactor
		import test.ui.viewmodel.ViewModel

		class SomeOtherThing {
		init {
		val viewModel = ViewModel(
		interactor = Interactor(
		repository = Repository(),
		),
		)
		}
		}
		""".trimIndent()
		)
		private val LEGITIMATE_FILES =
		arrayOf(
		MODEL_FILE,
		REPOSITORY_FILE,
		INTERACTOR_FILE,
		VIEW_MODEL_FILE,
		NON_CLEAN_ARCHITECTURE_FILE,
		)
		}
		}