Issue #8319: Update to Kotlin 1.4 and Coroutines 1.3.9.

build.gradle

@@ -204,6 +204,8 @@ subprojects {
 
                 packagingOptions {
                     exclude 'META-INF/atomicfu.kotlin_module'
+                    exclude 'META-INF/AL2.0'
+                    exclude 'META-INF/LGPL2.1'
                 }
 
                 aaptOptions {

buildSrc/src/main/java/Dependencies.kt

@@ -4,8 +4,8 @@
 
 // Synchronized version numbers for dependencies used by (some) modules
 object Versions {
-    const val kotlin = "1.3.71"
-    const val coroutines = "1.3.5"
+    const val kotlin = "1.4.10"
+    const val coroutines = "1.3.9"
 
     const val junit = "4.12"
     const val robolectric = "4.1"
@@ -17,7 +17,7 @@ object Versions {
     const val dokka = "0.9.17"
     const val android_gradle_plugin = "3.5.3"
     const val android_maven_publish_plugin = "3.6.2"
-    const val lint = "26.3.2"
+    const val lint = "27.0.1"
     const val detekt = "1.9.1"
 
     const val sentry = "1.7.21"

components/browser/engine-system/src/main/java/mozilla/components/browser/engine/system/matcher/UrlMatcher.kt

@@ -215,7 +215,7 @@ class UrlMatcher {
                 jsonReader -> loadCategories(jsonReader, categoryMap)
             }
 
-            var whiteList: WhiteList? = null
+            var whiteList: WhiteList?
             JsonReader(white).use { jsonReader -> whiteList = WhiteList.fromJson(jsonReader) }
             return UrlMatcher(enabledCategories, supportedCategories, categoryMap, whiteList)
         }

components/browser/icons/src/main/java/mozilla/components/browser/icons/pipeline/IconResourceComparator.kt

@@ -60,7 +60,7 @@ private fun IconRequest.Resource.Type.rank(): Int {
 }
 
 private val IconRequest.Resource.maxSize: Int
-    get() = sizes.asSequence().map { size -> size.minLength }.max() ?: 0
+    get() = sizes.asSequence().map { size -> size.minLength }.maxOrNull() ?: 0
 
 private val IconRequest.Resource.isContainerType: Boolean
     get() = mimeType != null && containerTypes.contains(mimeType)

components/browser/icons/src/main/java/mozilla/components/browser/icons/utils/Utils.kt

@@ -15,7 +15,7 @@ internal fun List<Pair<Int, Int>>.findBestSize(targetSize: Int, maxSize: Int, ma
         x >= targetSize && y >= targetSize && x <= maxSize && y <= maxSize
     }.filter { (x, y) ->
         x == y
-    }.minBy { (x, _) ->
+    }.minByOrNull { (x, _) ->
         x
     }
 
@@ -33,7 +33,7 @@ internal fun List<Pair<Int, Int>>.findBestSize(targetSize: Int, maxSize: Int, ma
             downScaledY >= targetSize &&
             downScaledX <= maxSize &&
             downScaledY <= maxSize
-    }.minBy { (x, _) ->
+    }.minByOrNull { (x, _) ->
         x
     }
 
@@ -51,7 +51,7 @@ internal fun List<Pair<Int, Int>>.findBestSize(targetSize: Int, maxSize: Int, ma
             upscaledY >= targetSize &&
             upscaledX <= maxSize &&
             upscaledY <= maxSize
-    }.maxBy { (x, _) ->
+    }.maxByOrNull { (x, _) ->
         x
     }
 

components/browser/storage-memory/src/main/java/mozilla/components/browser/storage/memory/InMemoryHistoryStorage.kt

@@ -117,7 +117,7 @@ class InMemoryHistoryStorage : HistoryStorage {
         }
         // Calculate maxScore so that we can invert our scoring.
         // Lower Levenshtein distance should produce a higher score.
-        val maxScore = urlMatches.maxBy { it.score }?.score ?: return@synchronized listOf()
+        val maxScore = urlMatches.maxByOrNull { it.score }?.score ?: return@synchronized listOf()
 
         // TODO exclude non-matching results entirely? Score that implies complete mismatch.
         matchedUrls.asSequence().sortedBy { it.value }.map {
@@ -126,8 +126,8 @@ class InMemoryHistoryStorage : HistoryStorage {
     }
 
     override fun getAutocompleteSuggestion(query: String): HistoryAutocompleteResult? = synchronized(pages) {
-        segmentAwareDomainMatch(query, pages.keys)?.let { urlMatch ->
-            return HistoryAutocompleteResult(
+        return segmentAwareDomainMatch(query, pages.keys)?.let { urlMatch ->
+            HistoryAutocompleteResult(
                 query, urlMatch.matchedSegment, urlMatch.url, AUTOCOMPLETE_SOURCE_NAME, pages.size)
         }
     }

components/concept/menu/src/main/java/mozilla/components/concept/menu/ext/MenuCandidate.kt

@@ -54,7 +54,7 @@ fun List<MenuCandidate>.findNestedMenuCandidate(id: Int): NestedMenuCandidate? =
 /**
  * Select the highlight with the highest priority.
  */
-fun Sequence<MenuEffect>.max() = maxBy {
+fun Sequence<MenuEffect>.max() = maxByOrNull {
     // Select the highlight with the highest priority
     when (it) {
         is HighPriorityHighlightEffect -> 2

components/feature/awesomebar/src/test/java/mozilla/components/feature/awesomebar/provider/BookmarksStorageSuggestionProviderTest.kt

@@ -154,7 +154,7 @@ class BookmarksStorageSuggestionProviderTest {
                 }
                 // Calculate maxScore so that we can invert our scoring.
                 // Lower Levenshtein distance should produce a higher score.
-                urlMatches.maxBy { it.score }?.score
+                urlMatches.maxByOrNull { it.score }?.score
                     ?: return@synchronized listOf()
 
                 // TODO exclude non-matching results entirely? Score that implies complete mismatch.

components/feature/push/src/main/java/mozilla/components/feature/push/Connection.kt

@@ -220,8 +220,7 @@ internal class RustPushConnection(
         // Query for the scope so that we can notify observers who the decrypted message is for.
         val scope = pushApi.dispatchInfoForChid(channelId)?.scope
 
-        scope?.let {
-
+        if (scope != null) {
             if (body == null) {
                 return DecryptedMessage(scope, null)
             }
@@ -235,6 +234,8 @@ internal class RustPushConnection(
             )
 
             return DecryptedMessage(scope, data)
+        } else {
+            return null
         }
     }
 

components/lib/crash/src/main/java/mozilla/components/lib/crash/service/MozillaSocorroService.kt

@@ -92,7 +92,7 @@ class MozillaSocorroService(
         if (versionName == DEFAULT_VERSION_NAME) {
             try {
                 versionName = applicationContext.packageManager
-                    .getPackageInfo(applicationContext.packageName, 0).versionName
+                    .getPackageInfo(applicationContext.packageName, 0).versionName ?: DEFAULT_VERSION_NAME
             } catch (e: PackageManager.NameNotFoundException) {
                 logger.error("package name not found, failed to get application version")
             } catch (e: IllegalStateException) {

components/lib/crash/src/main/java/mozilla/components/lib/crash/ui/CrashListAdapter.kt

@@ -86,23 +86,23 @@ internal class CrashListAdapter(
         val text = StringBuilder()
 
         text.append(crashWithReports.crash.uuid)
-        text.appendln()
+        text.appendLine()
         text.append(crashWithReports.crash.stacktrace.lines().first())
-        text.appendln()
+        text.appendLine()
 
         crashWithReports.reports.forEach { report ->
             val service = crashReporter.getCrashReporterServiceById(report.serviceId)
             text.append(" * ")
             text.append(service?.name ?: report.serviceId)
             text.append(": ")
             text.append(service?.createCrashReportUrl(report.reportId) ?: "<No URL>")
-            text.appendln()
+            text.appendLine()
         }
 
         text.append("----")
-        text.appendln()
+        text.appendLine()
         text.append(crashWithReports.crash.stacktrace)
-        text.appendln()
+        text.appendLine()
 
         val intent = Intent(Intent.ACTION_SEND)
         intent.type = "text/plain"

components/lib/jexl/src/main/java/mozilla/components/lib/jexl/ast/nodes.kt

@@ -177,7 +177,7 @@ private fun buildNodeDescription(
     append(" ( $name )")
 
     withinHeader()
-    appendln()
+    appendLine()
 
     block()
 }

components/lib/jexl/src/main/java/mozilla/components/lib/jexl/lexer/Lexer.kt

@@ -100,7 +100,7 @@ internal class Lexer(private val grammar: Grammar) {
 
     @Suppress("ReturnCount")
     private fun isElement(input: LexerInput, elements: Map<String, GrammarElement>): Boolean {
-        val max = elements.keys.map { it.length }.max() ?: return false
+        val max = elements.keys.map { it.length }.maxOrNull() ?: return false
 
         for (steps in max downTo 1) {
             val candidate = input.peekRange(steps)

components/tooling/detekt/build.gradle

@@ -17,6 +17,13 @@ dependencies {
     testImplementation Dependencies.tools_detekt_test
 }
 
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
+    // Gradle keeps warning about different Kotlin versions being on the classpath. I am unsure
+    // how to resolve that and if it is even resolvable in this cross-library setup. Anyhow,
+    // since it is only a warning I am going to suppress them for this project specifically.
+    kotlinOptions.allWarningsAsErrors = false
+}
+
 tasks.register("lintRelease") {
     doLast {
         // Do nothing. We execute the same set of tasks for all our modules in parallel on taskcluster.

components/tooling/glean-gradle-plugin/build.gradle

@@ -13,6 +13,13 @@ repositories {
     mavenCentral()
 }
 
+tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile).all {
+    // Gradle keeps warning about different Kotlin versions being on the classpath. I am unsure
+    // how to resolve that and if it is even resolvable in this cross-library setup. Anyhow,
+    // since it is only a warning I am going to suppress them for this project specifically.
+    kotlinOptions.allWarningsAsErrors = false
+}
+
 dependencies {
     implementation gradleApi()
     implementation localGroovy()

components/tooling/lint/build.gradle

@@ -10,7 +10,16 @@ sourceCompatibility = JavaVersion.VERSION_1_8
 
 dependencies {
   compileOnly Dependencies.tools_lintapi
+
+  // Force the usage of /our/ Kotlin version and not what we get transitively from the lint
+  // dependencies. Otherwise we end up with a warning that there are multiple versions on the
+  // classpath.
   compileOnly Dependencies.kotlin_stdlib
+  compileOnly "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${Versions.kotlin}"
+  compileOnly Dependencies.kotlin_reflect
+  testImplementation Dependencies.kotlin_stdlib
+  testImplementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${Versions.kotlin}"
+  testImplementation Dependencies.kotlin_reflect
 
   testImplementation Dependencies.tools_lint
   testImplementation Dependencies.tools_linttests

components/tooling/lint/src/main/java/mozilla/components/tooling/lint/AndroidSrcXmlDetector.kt

@@ -9,7 +9,6 @@ import com.android.SdkConstants.FQCN_IMAGE_BUTTON
 import com.android.SdkConstants.FQCN_IMAGE_VIEW
 import com.android.SdkConstants.IMAGE_BUTTON
 import com.android.SdkConstants.IMAGE_VIEW
-import com.android.annotations.VisibleForTesting
 import com.android.resources.ResourceFolderType
 import com.android.tools.lint.detector.api.Category
 import com.android.tools.lint.detector.api.Implementation
@@ -18,6 +17,7 @@ import com.android.tools.lint.detector.api.ResourceXmlDetector
 import com.android.tools.lint.detector.api.Scope
 import com.android.tools.lint.detector.api.Severity
 import com.android.tools.lint.detector.api.XmlContext
+import com.google.common.annotations.VisibleForTesting
 import org.w3c.dom.Element
 
 /**