Prototype of inlay hints for suspending calls (KT-20187)

idea/idea-test-framework/src/org/jetbrains/kotlin/idea/test/DirectiveBasedActionUtils.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
- *
- * 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.
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
  */
 
 package org.jetbrains.kotlin.idea.test
@@ -85,6 +74,7 @@ object DirectiveBasedActionUtils {
             "Show function return type hints",
             "Show property type hints",
             "Show parameter type hints",
-            "Show argument name hints"
+            "Show argument name hints",
+            "Show hints for suspending calls"
     )
 }

idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt

@@ -14,6 +14,7 @@ import com.intellij.lang.java.JavaLanguage
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.idea.actions.internal.KotlinInternalMode
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.quickfix.createFromUsage.callableBuilder.getReturnTypeReference
 import org.jetbrains.kotlin.name.Name
@@ -83,9 +84,11 @@ enum class HintType(desc: String, enabled: Boolean) {
         override fun isApplicable(elem: PsiElement): Boolean = elem is KtValueArgumentList
     },
 
+
     LAMBDA_RETURN_EXPRESSION("Show lambda return expression hints", true) {
         override fun isApplicable(elem: PsiElement) =
-            elem is KtExpression && elem !is KtLambdaExpression && elem !is KtFunctionLiteral
+            elem is KtExpression && elem !is KtLambdaExpression && elem !is KtFunctionLiteral &&
+                    !elem.isNameReferenceInCall()
 
         override fun provideHints(elem: PsiElement): List<InlayInfo> {
             if (elem is KtExpression) {
@@ -104,6 +107,14 @@ enum class HintType(desc: String, enabled: Boolean) {
             }
             return emptyList()
         }
+    },
+    SUSPENDING_CALL("Show hints for suspending calls", false) {
+        override fun isApplicable(elem: PsiElement) = elem.isNameReferenceInCall() && KotlinInternalMode.enabled
+
+        override fun provideHints(elem: PsiElement): List<InlayInfo> {
+            val callExpression = elem.parent as? KtCallExpression ?: return emptyList()
+            return provideSuspendingCallHint(callExpression)?.let { listOf(it) } ?: emptyList()
+        }
     };
 
     companion object {
@@ -178,3 +189,5 @@ class KotlinInlayParameterHintsProvider : InlayParameterHintsProvider {
     }
 }
 
+private fun PsiElement.isNameReferenceInCall() =
+    this is KtNameReferenceExpression && parent is KtCallExpression

idea/src/org/jetbrains/kotlin/idea/parameterInfo/SuspendingCallHints.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.parameterInfo
+
+import com.intellij.codeInsight.hints.InlayInfo
+import org.jetbrains.kotlin.backend.common.descriptors.isSuspend
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.psi.KtCallExpression
+import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+
+fun provideSuspendingCallHint(callExpression: KtCallExpression): InlayInfo? {
+    val bindingContext = callExpression.analyze(BodyResolveMode.PARTIAL)
+    val call = bindingContext[BindingContext.CALL, callExpression.calleeExpression] ?: return null
+    val resolvedCall = bindingContext[BindingContext.RESOLVED_CALL, call] ?: return null
+    if (resolvedCall.candidateDescriptor.isSuspend) {
+        return InlayInfo(TYPE_INFO_PREFIX + "#", callExpression.calleeExpression?.startOffset ?: callExpression.startOffset)
+    }
+    return null
+}

idea/tests/org/jetbrains/kotlin/idea/parameterInfo/SuspendingCallHintsTest.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.parameterInfo
+
+import org.jetbrains.kotlin.idea.actions.internal.KotlinInternalMode
+import org.jetbrains.kotlin.idea.test.KotlinLightCodeInsightFixtureTestCase
+import org.jetbrains.kotlin.idea.test.KotlinLightProjectDescriptor
+import org.jetbrains.kotlin.idea.test.KotlinWithJdkAndRuntimeLightProjectDescriptor
+
+class SuspendingCallHintsTest : KotlinLightCodeInsightFixtureTestCase() {
+    override fun getProjectDescriptor(): KotlinLightProjectDescriptor = KotlinWithJdkAndRuntimeLightProjectDescriptor.INSTANCE
+
+    fun check(text: String) {
+        KotlinInternalMode.enabled = true
+        try {
+            HintType.SUSPENDING_CALL.option.set(true)
+            myFixture.configureByText("A.kt", text)
+            myFixture.testInlays()
+        } finally {
+            KotlinInternalMode.enabled = false
+        }
+    }
+
+    fun testSimple() {
+        check(
+            """import kotlin.coroutines.experimental.buildSequence
+
+             val x = buildSequence {<hint text="this: SequenceBuilder<Int>" />
+                 <hint text="#" />yield(<hint text="value:" />1)
+             } """
+        )
+    }
+}