Lint checks for colorAccent and colorPrimaryDark

catalog/build.gradle

@@ -18,6 +18,8 @@ dependencies {
 
   api compatibility("recyclerViewSelection")
 
+  lintChecks project(':lint-checks')
+
   androidTestImplementation "androidx.test:core:${project.rootProject.ext.testRunnerVersion}"
   androidTestImplementation "androidx.test:runner:${project.rootProject.ext.testRunnerVersion}"
   androidTestImplementation "androidx.test:rules:${project.rootProject.ext.testRunnerVersion}"

lint-checks/README.md

@@ -0,0 +1,59 @@
+## Lint checks
+
+- `ThemeCheckColorAccent` : Detects usages colorAccent in style resources
+- `ThemeCheckColorPrimaryDark` : Detects usages colorPrimaryDark in style resources
+
+## Setup in your project
+
+In order to get the lint checks running on the code in your module:
+
+1.  Open the `build.gradle` file for your application.
+2.  Make sure that the `repositories` section includes Google's Maven Repository
+    `google()`. For example:
+
+    ```groovy
+      allprojects {
+        repositories {
+          google()
+          jcenter()
+        }
+      }
+    ```
+
+3.  Add the library to the `dependencies` section:
+
+    ```groovy
+      dependencies {
+        // ...
+        lintChecks 'com.google.android.material:material-lint-checks:x.x.x'
+        // ...
+      }
+    ```
+
+Visit
+[Google's Maven Repository](https://maven.google.com/web/index.html#com.google.android.material:material-lint-checks)
+or
+[MVN Repository](https://mvnrepository.com/artifact/com.google.android.material/material-lint-checks)
+to find the latest version of the library.
+
+## Usage
+
+Run lint on your app module with the following Gradle command:
+
+```
+./gradlew app:lintDebug
+```
+
+## Disable Lint checks:
+
+If you only need some of lint checks included you can disable them as follows:
+
+In your `build.gradle` file:
+
+```
+android {
+   lintOptions {
+        disable 'ThemeCheckColorAccent', 'ThemeCheckColorPrimaryDark'
+    }
+}
+```

lint-checks/build.gradle

@@ -0,0 +1,17 @@
+apply plugin: 'kotlin'
+
+dependencies {
+  compileOnly "org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion"
+  compileOnly "com.android.tools.lint:lint-api:27.0.1"
+  compileOnly "com.android.tools.lint:lint-checks:27.0.1"
+
+  testImplementation "com.android.tools.lint:lint-tests:27.0.1"
+  testImplementation "junit:junit:4.12"
+  testImplementation "org.assertj:assertj-core:3.9.0"
+}
+
+jar {
+  manifest {
+    attributes("Lint-Registry-v2": "com.google.android.material.lint.checks.IssueRegistry")
+  }
+}

lint-checks/src/main/java/com/google/android/material/lint/checks/IssueRegistry.kt

@@ -0,0 +1,19 @@
+package com.google.android.material.lint.checks
+
+import com.android.tools.lint.client.api.IssueRegistry
+import com.android.tools.lint.detector.api.CURRENT_API
+import com.android.tools.lint.detector.api.Issue
+
+/**
+ * The class contains the list of issues that will be checked when running lint.
+ */
+
+class IssueRegistry : IssueRegistry() {
+
+  override val api: Int = CURRENT_API
+
+  override val issues: List<Issue> = listOf(
+    ThemeCheckColorAccentDetector.ISSUE,
+    ThemeCheckColorPrimaryDarkDetector.ISSUE
+  )
+}

lint-checks/src/main/java/com/google/android/material/lint/checks/ThemeCheckColorAccentDetector.kt

@@ -0,0 +1,65 @@
+package com.google.android.material.lint.checks
+
+import com.android.resources.ResourceFolderType
+import com.android.tools.lint.detector.api.*
+import org.w3c.dom.Attr
+import org.w3c.dom.Element
+import org.w3c.dom.Node
+
+class ThemeCheckColorAccentDetector : ResourceXmlDetector() {
+
+  companion object {
+    val ISSUE = Issue.create(
+      id = "ThemeCheckColorAccent",
+      briefDescription = "Detects usages colorAccent in style resources",
+      explanation = "The colorAccent is superseded by newer theme attribute colorSecondary in style resources",
+      category = Category.CORRECTNESS,
+      severity = Severity.WARNING,
+      implementation = Implementation(
+        ThemeCheckColorAccentDetector::class.java,
+        Scope.RESOURCE_FILE_SCOPE
+      )
+    )
+    private const val NODE_STYLE = "style"
+    private const val NODE_ITEM = "item"
+    private const val ATTR_NAME = "name"
+    private const val COLOR_ACCENT = "colorAccent"
+  }
+
+  override fun appliesTo(folderType: ResourceFolderType): Boolean {
+    //we only need to analyze 'style' in the 'values' resource folder.
+    return folderType == ResourceFolderType.VALUES
+  }
+
+  override fun getApplicableElements(): Collection<String>? {
+    //we want to analyze every `<item>` element that is declared in XML.
+    return setOf(NODE_ITEM)
+  }
+
+  override fun visitElement(context: XmlContext, element: Element) {
+
+    if (element.hasAttribute(ATTR_NAME) && element.parentNode.nodeName == NODE_STYLE) {
+      visitAttribute(context,element.getAttributeNode(ATTR_NAME))
+    }
+  }
+
+  override fun visitAttribute(context: XmlContext, attribute: Attr) {
+
+    val attributeName = attribute.nodeValue
+
+    if (attributeName == COLOR_ACCENT) {
+
+      context.report(
+        issue = ISSUE,
+        scope = attribute,
+        location = context.getLocation(attribute.ownerElement),
+        message = "colorAccent is superseded by newer theme attribute colorSecondary",
+        quickfixData = LintFix.create()
+          .replace()
+          .text("colorAccent")
+          .with("colorSecondary")
+          .build()
+      )
+    }
+  }
+}

lint-checks/src/main/java/com/google/android/material/lint/checks/ThemeCheckColorPrimaryDarkDetector.kt

@@ -0,0 +1,67 @@
+package com.google.android.material.lint.checks
+
+import com.android.resources.ResourceFolderType
+import com.android.tools.lint.detector.api.*
+import org.w3c.dom.Attr
+import org.w3c.dom.Element
+import org.w3c.dom.Node
+
+class ThemeCheckColorPrimaryDarkDetector : ResourceXmlDetector() {
+
+  companion object {
+    val ISSUE = Issue.create(
+      id = "ThemeCheckColorPrimaryDark",
+      briefDescription = "Detects usages colorPrimaryDark in style resources",
+      explanation = "The colorPrimaryDark is superseded by newer theme attribute colorPrimaryVariant in style resources",
+      category = Category.CORRECTNESS,
+      severity = Severity.WARNING,
+      implementation = Implementation(
+        ThemeCheckColorPrimaryDarkDetector::class.java,
+        Scope.RESOURCE_FILE_SCOPE
+      )
+    )
+    private const val NODE_STYLE = "style"
+    private const val NODE_ITEM = "item"
+    private const val ATTR_NAME = "name"
+    private const val COLOR_PRIMARY_DARK = "colorPrimaryDark"
+  }
+
+  override fun appliesTo(folderType: ResourceFolderType): Boolean {
+    //we only need to analyze 'style' in the 'values' resource folder.
+    return folderType == ResourceFolderType.VALUES
+  }
+
+  override fun getApplicableElements(): Collection<String>? {
+    //we want to analyze every `<item>` element that is declared in XML.
+    return setOf(NODE_ITEM)
+  }
+
+  override fun visitElement(context: XmlContext, element: Element) {
+
+    if (element.hasAttribute(ATTR_NAME) && element.parentNode.nodeName == NODE_STYLE) {
+      visitAttribute(context,element.getAttributeNode(ATTR_NAME))
+    }
+  }
+
+  override fun visitAttribute(context: XmlContext, attribute: Attr) {
+
+    val attributeName = attribute.nodeValue
+
+    if (attributeName == COLOR_PRIMARY_DARK) {
+
+      context.report(
+              issue = ISSUE,
+              scope = attribute,
+              location = context.getLocation(attribute.ownerElement),
+              message = "colorPrimaryDark is superseded by newer theme attribute colorPrimaryVariant",
+              quickfixData = LintFix.create()
+                      .replace()
+                      .text("colorPrimaryDark")
+                      .with("colorPrimaryVariant")
+                      .build()
+      )
+    }
+  }
+}
+
+

lint-checks/src/test/java/com/google/android/material/lint/checks/ThemeCheckColorAccentDetectorTest.kt

@@ -0,0 +1,61 @@
+package com.google.android.material.lint.checks
+
+import com.android.tools.lint.checks.infrastructure.LintDetectorTest
+import com.android.tools.lint.detector.api.Detector
+import com.android.tools.lint.detector.api.Issue
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(JUnit4::class)
+class ThemeCheckColorAccentDetectorTest : LintDetectorTest() {
+
+  override fun getIssues(): MutableList<Issue> = mutableListOf(ThemeCheckColorAccentDetector.ISSUE)
+
+  override fun getDetector(): Detector = ThemeCheckColorAccentDetector()
+
+  @Test
+  fun expectPass() {
+    lint()
+      .allowMissingSdk(true)
+      .files(
+        xml(
+          "res/values/styles.xml", """
+<resources>
+   <style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
+     <item name="colorPrimary">@color/blu500</item>
+   </style>
+</resources>
+                """
+        )
+      )
+      .run()
+      .expectClean()
+  }
+
+  @Test
+  fun expectFail() {
+    lint()
+      .allowMissingSdk(true)
+      .files(
+        xml(
+          "res/values/styles.xml", """
+<resources>
+   <style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
+     <item name="colorAccent">@color/blu500</item>
+   </style>
+</resources>
+                """
+        )
+      )
+      .run()
+      .expect(
+        """
+res/values/styles.xml:4: Warning: colorAccent is superseded by newer theme attribute colorSecondary [ThemeCheckColorAccent]
+     <item name="colorAccent">@color/blu500</item>
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+0 errors, 1 warnings
+            """
+      )
+  }
+}

lint-checks/src/test/java/com/google/android/material/lint/checks/ThemeCheckColorPrimaryDarkDetectorTest.kt

@@ -0,0 +1,61 @@
+package com.google.android.material.lint.checks
+
+import com.android.tools.lint.checks.infrastructure.LintDetectorTest
+import com.android.tools.lint.detector.api.Detector
+import com.android.tools.lint.detector.api.Issue
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(JUnit4::class)
+class ThemeCheckColorPrimaryDarkDetectorTest : LintDetectorTest() {
+
+  override fun getIssues(): MutableList<Issue> = mutableListOf(ThemeCheckColorPrimaryDarkDetector.ISSUE)
+
+  override fun getDetector(): Detector = ThemeCheckColorPrimaryDarkDetector()
+
+  @Test
+  fun expectPass() {
+    lint()
+      .allowMissingSdk(true)
+      .files(
+        xml(
+          "res/values/styles.xml", """
+<resources>
+   <style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
+     <item name="colorPrimary">@color/blu500</item>
+   </style>
+</resources>
+                """
+        )
+      )
+      .run()
+      .expectClean()
+  }
+
+  @Test
+  fun expectFail() {
+    lint()
+      .allowMissingSdk(true)
+      .files(
+        xml(
+          "res/values/styles.xml", """
+<resources>
+   <style name="AppTheme" parent="Theme.MaterialComponents.DayNight">
+     <item name="colorPrimaryDark">@color/blu500</item>
+   </style>
+</resources>
+                """
+        )
+      )
+      .run()
+      .expect(
+        """
+res/values/styles.xml:4: Warning: colorPrimaryDark is superseded by newer theme attribute colorPrimaryVariant [ThemeCheckColorPrimaryDark]
+     <item name="colorPrimaryDark">@color/blu500</item>
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+0 errors, 1 warnings
+            """
+      )
+  }
+}

settings.gradle

@@ -6,6 +6,8 @@ include ':testing:java:com:google:android:material:testapp:base'
 include ':testing:java:com:google:android:material:testapp:custom'
 include ':testing:java:com:google:android:material:testapp:theme'
 
+include ':lint-checks'
+
 include ':catalog'
 
 rootProject.children.each { p ->