Migrate for moved and renamed buildSequence/buildIterator (KT-26679)

#KT-26679 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/migration/ObsoleteExperimentalCoroutinesInspection.kt

@@ -12,6 +12,7 @@ import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
+import org.jetbrains.kotlin.idea.codeInsight.shorten.performDelayedRefactoringRequests
 import org.jetbrains.kotlin.idea.configuration.MigrationInfo
 import org.jetbrains.kotlin.idea.configuration.isLanguageVersionUpdate
 import org.jetbrains.kotlin.idea.imports.importableFqName
@@ -52,10 +53,21 @@ class ObsoleteExperimentalCoroutinesInspection : AbstractKotlinInspection(), Cle
 
     companion object {
         private val PROBLEMS = listOf(
+            ObsoleteTopLevelFunctionUsage(
+                "buildSequence",
+                "kotlin.coroutines.experimental.buildSequence",
+                "kotlin.sequences.sequence"
+            ),
+            ObsoleteTopLevelFunctionUsage(
+                "buildIterator",
+                "kotlin.coroutines.experimental.buildIterator",
+                "kotlin.sequences.iterator"
+            ),
             ObsoleteExtensionFunctionUsage(
                 "resume",
                 "kotlin.coroutines.experimental.Continuation.resume",
-                "kotlin.coroutines.resume"),
+                "kotlin.coroutines.resume"
+            ),
             ObsoleteExtensionFunctionUsage(
                 "resumeWithException",
                 "kotlin.coroutines.experimental.Continuation.resumeWithException",
@@ -87,6 +99,56 @@ private class ObsoleteCoroutineUsageFix(val delegate: CoroutineFix) : LocalQuick
     }
 }
 
+private class ObsoleteTopLevelFunctionUsage(
+    val textMarker: String, val oldFqName: String, val newFqName: String
+) : CoroutineMigrationProblem {
+    override fun report(holder: ProblemsHolder, isOnTheFly: Boolean, simpleNameExpression: KtSimpleNameExpression): Boolean {
+        if (simpleNameExpression.text != textMarker) return false
+
+        if (simpleNameExpression.parent !is KtCallExpression) return false
+
+        val descriptor = simpleNameExpression.resolveMainReferenceToDescriptors().firstOrNull() ?: return false
+        val callableDescriptor = descriptor as? CallableDescriptor ?: return false
+
+        val resolvedToFqName = callableDescriptor.fqNameOrNull()?.asString() ?: return false
+        if (resolvedToFqName != oldFqName) return false
+
+        val project = simpleNameExpression.project
+
+        KotlinTopLevelFunctionFqnNameIndex.getInstance()
+            .get(newFqName, project, GlobalSearchScope.allScope(project))
+            .asSequence()
+            .firstOrNull() ?: return false
+
+        val problemDescriptor = holder.manager.createProblemDescriptor(
+            simpleNameExpression,
+            simpleNameExpression,
+            "`$newFqName` is expected to be used since Kotlin 1.3",
+            ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
+            isOnTheFly,
+            ObsoleteCoroutineUsageFix(fix)
+        )
+        holder.registerProblem(problemDescriptor)
+
+        return true
+    }
+
+    private val fix = RebindReferenceFix(newFqName)
+
+    companion object {
+        private class RebindReferenceFix(val fqName: String) : ObsoleteCoroutineUsageFix.Companion.CoroutineFix {
+            override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+                val element = descriptor.psiElement
+                if (element !is KtSimpleNameExpression) return
+
+                element.mainReference.bindToFqName(FqName(fqName), KtSimpleNameReference.ShorteningMode.DELAYED_SHORTENING)
+
+                performDelayedRefactoringRequests(project)
+            }
+        }
+    }
+}
+
 private class ObsoleteExtensionFunctionUsage(
     val textMarker: String, val oldFqName: String, newFqName: String
 ) : CoroutineMigrationProblem {

idea/testData/quickfix/obsoleteCoroutines/buildSequence.kt

@@ -1,8 +1,10 @@
 // "Fix experimental coroutines usage" "true"
-// ERROR: Unresolved reference: buildSequence
+// WITH_RUNTIME
-import kotlin.coroutines.<caret>experimental.buildSequence
+package some
+
+import kotlin.coroutines.experimental.buildSequence
 
 fun main(args: Array<String>) {
-    val lazySeq = buildSequence<Int> {
+    val lazySeq = <caret>buildSequence<Int> {
     }
 }

idea/testData/quickfix/obsoleteCoroutines/buildSequence.kt.after

@@ -1,7 +1,10 @@
 // "Fix experimental coroutines usage" "true"
-// ERROR: Unresolved reference: buildSequence
+// WITH_RUNTIME
+package some
+
+import kotlin.coroutines.experimental.buildSequence
 
 fun main(args: Array<String>) {
-    val lazySeq = buildSequence<Int> {
+    val lazySeq = sequence<Int> {
     }
 }

idea/testData/quickfix/obsoleteCoroutines/buildSequenceImport.kt

@@ -0,0 +1,8 @@
+// "Fix experimental coroutines usage" "true"
+// ERROR: Unresolved reference: buildSequence
+import kotlin.coroutines.<caret>experimental.buildSequence
+
+fun main(args: Array<String>) {
+    val lazySeq = buildSequence<Int> {
+    }
+}

idea/testData/quickfix/obsoleteCoroutines/buildSequenceImport.kt.after

@@ -0,0 +1,7 @@
+// "Fix experimental coroutines usage" "true"
+// ERROR: Unresolved reference: buildSequence
+
+fun main(args: Array<String>) {
+    val lazySeq = buildSequence<Int> {
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -8304,6 +8304,11 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             runTest("idea/testData/quickfix/obsoleteCoroutines/buildSequence.kt");
         }
 
+        @TestMetadata("buildSequenceImport.kt")
+        public void testBuildSequenceImport() throws Exception {
+            runTest("idea/testData/quickfix/obsoleteCoroutines/buildSequenceImport.kt");
+        }
+
         @TestMetadata("resume.kt")
         public void testResume() throws Exception {
             runTest("idea/testData/quickfix/obsoleteCoroutines/resume.kt");