Collect specific classes before running lint detector
I want to write a lint check to ensure that @ContributesAndroidInjector was added to all fragments that need it.
Is there a way to gather all classes that are annotated with @Module before visitClass(node: UClass) is called?
Now I have manually added all modules in a list (see code example), but that is not the right solution for me as I would constantly need to update my detector when new modules are added.
Detector:
class MissingContributorDetector : Detector(), Detector.UastScanner {
override fun getApplicableUastTypes(): List<Class<out UElement>> {
return listOf(UClass::class.java)
}
override fun createUastHandler(context: JavaContext) = Visitor(context)
class Visitor(private val context: JavaContext) : UElementHandler() {
private val returnTypes: List<String>
init {
returnTypes = MODULES.mapNotNull { context.evaluator.findClass(it) }
.flatMap { it.methods.toList() }
.filter { it.hasAnnotation(DAGGER_MODULE_ANNOTATION) }
.mapNotNull { it.returnType }
.mapNotNull { PsiUtil.resolveClassInType(it)?.qualifiedName }
}
override fun visitClass(node: UClass) {
// logic to determine if there is an issue
}
}
companion object {
private val MODULES = listOf(
"com.dagger.module.ModuleOne",
"com.dagger.module.ModuleTwo",
"com.dagger.module.ModuleThree",
)
}
}
Module:
@Module
abstract class ModuleOne {
@ContributesAndroidInjector
abstract fun contributesFragment(): HomeFragment
}
Solution
Is there a way to gather all classes that are annotated with @Module before visitClass(node: UClass) is called?
The detector can be written to perform two passes. The first pass will collect all the class in a data structure which will be available to the detector during the second pass. In this scheme, visitClass() will be called for each class during the first and second passes.
MissingContributorDetector.kt
/*
Process this lint check in two passes. The fist pass collects all the classes that have
the @Module annotation. The second pass does the actual check but has a the class list
produced in the first pass at its disposal.
*/
class MissingContributorDetector : Detector(), Detector.UastScanner {
private val mModuleClasses: MutableList<UClass> = ArrayList()
override fun getApplicableUastTypes(): List<Class<out UElement>> {
return listOf(UClass::class.java)
}
override fun createUastHandler(context: JavaContext) = Visitor(context)
// Cues up the second phase for the actual lint check.
override fun afterCheckEachProject(context: Context) {
super.afterCheckEachProject(context)
if (context.phase == 1) { // Rescan classes
context.requestRepeat(this, MissingContributorIssue.implementation.scope)
}
}
inner class Visitor(private val context: JavaContext) : UElementHandler() {
// Search for classes that are annotated with @Module
override fun visitClass(node: UClass) {
if (context.phase == 1) { // Just collect class names
if (hasAnnotation(node.annotations, DAGGER_MODULE_ANNOTATION_QUALIFIED_NAME)) {
// Build the class list that will be used during the second pass.
mModuleClasses.add(node)
}
} else { // phase 2
// Do whatever processing is necessary. Here we just check for
// @ContributesAndroidInjector on each method in a class annotated with @Module.
// The mModuleClasses structure is fully populated from the first pass.
if (mModuleClasses.contains(node)) {
node.methods.forEach { checkMethodForContributesAndroidInjector(it) }
}
}
}
// Check for @ContributesAndroidInjector on non-constructor methods
private fun checkMethodForContributesAndroidInjector(node: UMethod) {
if (node.isConstructor ||
!isFragmentReturnType(node) ||
hasAnnotation(node.annotations, DAGGER_CONTRIBUTESANDROIDINJECTOR_QUALIFIED_NAME)) {
return
}
context.report(
MissingContributorIssue,
node,
context.getNameLocation(node),
MissingContributorIssue.getExplanation(TextFormat.TEXT)
)
}
private fun isFragmentReturnType(node: UMethod): Boolean {
val returnTypeRef = node.returnTypeReference
return returnTypeRef?.getQualifiedName() == HOME_FRAGMENT
}
private fun hasAnnotation(annotations: List<UAnnotation>, toCheck: String): Boolean {
return annotations.any { it.qualifiedName == toCheck }
}
}
companion object {
const val DAGGER_MODULE_ANNOTATION_QUALIFIED_NAME = "dagger.Module"
const val DAGGER_CONTRIBUTESANDROIDINJECTOR_QUALIFIED_NAME = "dagger.android.ContributesAndroidInjector"
const val HOME_FRAGMENT = "com.dagger.module.HomeFragment"
val MissingContributorIssue: Issue = Issue.create(
id = "MissingContributesAndroidInjector",
briefDescription = "Must specify @ContributesAndroidInjector",
implementation = Implementation(
MissingContributorDetector::class.java,
Scope.JAVA_FILE_SCOPE),
explanation = "Method must be annotated with @ContributesAndroidInjector if enclosing class is annotated with @Module.",
category = Category.CORRECTNESS,
priority = 1,
severity = Severity.FATAL
)
}
}
Old answer with just one pass
The detector can be written to look at each class and to select only those classes that are annotated with @Module. Once a class is selected, each method that returns a HomeFragment can be checked for the @ContributesAndroidInjector annotation. Classes can then be added and scanned without updating a list of modules.
MissingContributorDetector.kt
class MissingContributorDetector : Detector(), Detector.UastScanner {
override fun getApplicableUastTypes(): List<Class<out UElement>> {
return listOf(UClass::class.java)
}
override fun createUastHandler(context: JavaContext) = Visitor(context)
class Visitor(private val context: JavaContext) : UElementHandler() {
// Search for classes that are annotated with @Module
override fun visitClass(node: UClass) {
if (hasAnnotation(node.annotations, DAGGER_MODULE_ANNOTATION_QUALIFIED_NAME)) {
node.methods.forEach { checkMethodForContributesAndroidInjector(it) }
}
}
// Check for @ContributesAndroidInjector on non-constructor methods
private fun checkMethodForContributesAndroidInjector(node: UMethod) {
if (node.isConstructor ||
!isFragmentReturnType(node) ||
hasAnnotation(node.annotations, DAGGER_CONTRIBUTESANDROIDINJECTOR_QUALIFIED_NAME)) {
return
}
context.report(
MissingContributorIssue.ISSUE,
node,
context.getNameLocation(node),
MissingContributorIssue.ISSUE.getExplanation(TextFormat.TEXT)
)
}
private fun isFragmentReturnType(node: UMethod): Boolean {
val returnTypeRef = node.returnTypeReference
return returnTypeRef?.getQualifiedName() == HOME_FRAGMENT
}
private fun hasAnnotation(annotations: List<UAnnotation>, toCheck: String): Boolean {
return annotations.any { it.qualifiedName == toCheck }
}
}
object MissingContributorIssue {
private const val ID = "MissingContributesAndroidInjector"
private const val DESCRIPTION = "Must specify @ContributesAndroidInjector"
private const val EXPLANATION = ("Method must be annotated with @ContributesAndroidInjector if enclosing class is annotated with @Module.")
private val CATEGORY: Category = Category.CORRECTNESS
private const val PRIORITY = 1
private val SEVERITY = Severity.FATAL
val ISSUE: Issue = Issue.create(
ID,
DESCRIPTION,
EXPLANATION,
CATEGORY,
PRIORITY,
SEVERITY,
Implementation(
MissingContributorDetector::class.java,
Scope.JAVA_FILE_SCOPE)
)
}
companion object {
const val DAGGER_MODULE_ANNOTATION_QUALIFIED_NAME = "dagger.Module"
const val DAGGER_CONTRIBUTESANDROIDINJECTOR_QUALIFIED_NAME = "dagger.android.ContributesAndroidInjector"
const val HOME_FRAGMENT = "com.dagger.module.HomeFragment"
}
}
A file to test this detector:
ModuleOne.kt
@Module
abstract class ModuleOne {
@ContributesAndroidInjector
abstract fun isAnnotated(): HomeFragment
abstract fun shouldBeAnnotated(): HomeFragment
abstract fun notAnnotated()
}
abstract class ModuleTwo {
abstract fun okIsNotAnnotated(): HomeFragment
}
The lint report showing flagged items:
