Support toRegex() standard function

#KT-8088 Fixed

idea/resources/injection/kotlinInjections.xml

@@ -5,5 +5,8 @@
         <place><![CDATA[
             psiParameter().ofMethod(0, psiMethod().withName("Regex").definedInClass("kotlin.text.Regex"))
             ]]></place>
+        <place><![CDATA[
+            receiver().ofMethod(psiMethod().withName("toRegex").withReceiver("kotlin.String").definedInPackage("kotlin.text"))
+            ]]></place>
     </injection>
 </component>

idea/src/org/jetbrains/kotlin/idea/injection/KotlinLanguageInjector.kt

@@ -18,13 +18,11 @@ package org.jetbrains.kotlin.idea.injection
 
 import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.util.TextRange
-import com.intellij.psi.InjectedLanguagePlaces
-import com.intellij.psi.LanguageInjector
-import com.intellij.psi.PsiLanguageInjectionHost
-import com.intellij.psi.PsiMethod
+import com.intellij.psi.*
 import com.intellij.psi.util.PsiTreeUtil
 import org.intellij.plugins.intelliLang.Configuration
 import org.intellij.plugins.intelliLang.inject.InjectorUtils
+import org.intellij.plugins.intelliLang.inject.config.BaseInjection
 import org.intellij.plugins.intelliLang.inject.java.JavaLanguageInjectionSupport
 import org.jetbrains.kotlin.psi.*
 import java.util.*
@@ -41,6 +39,7 @@ class KotlinLanguageInjector : LanguageInjector {
         val injectionInfo =
                 injectWithExplicitCodeInstruction(ktHost)
                 ?: injectWithCall(ktHost)
+                ?: injectWithReceiver(ktHost)
                 ?: return
 
         val language = InjectorUtils.getLanguageByString(injectionInfo.languageId) ?: return
@@ -53,6 +52,28 @@ class KotlinLanguageInjector : LanguageInjector {
         return InjectionInfo(languageId, null, null)
     }
 
+    private fun injectWithReceiver(host: KtElement): InjectionInfo? {
+        val qualifiedExpression = host.parent as? KtDotQualifiedExpression ?: return null
+        if (qualifiedExpression.receiverExpression != host) return null
+
+        val callExpression = qualifiedExpression.selectorExpression as? KtCallExpression ?: return null
+        val callee = callExpression.calleeExpression ?: return null
+
+        for (reference in callee.references) {
+            ProgressManager.checkCanceled()
+
+            val resolvedTo = reference.resolve()
+            if (resolvedTo is KtFunction) {
+                val injectionInfo = findInjection(resolvedTo.receiverTypeReference, Configuration.getInstance().getInjections(KOTLIN_SUPPORT_ID))
+                if (injectionInfo != null) {
+                    return injectionInfo
+                }
+            }
+        }
+
+        return null
+    }
+
     private fun injectWithCall(host: KtElement): InjectionInfo? {
         val ktHost: KtElement = host
         val argument = ktHost.parent as? KtValueArgument ?: return null
@@ -85,26 +106,19 @@ class KotlinLanguageInjector : LanguageInjector {
         val argumentIndex = (argument.parent as KtValueArgumentList).arguments.indexOf(argument)
         val psiParameter = javaMethod.parameterList.parameters.getOrNull(argumentIndex) ?: return null
 
-        val injections = Configuration.getInstance().getInjections(JavaLanguageInjectionSupport.JAVA_SUPPORT_ID)
-
-        for (injection in injections) {
-            if (injection.acceptsPsiElement(psiParameter)) {
-                // ?? if (!processXmlInjections(injection, owner, method, paramIndex)) {
-                return InjectionInfo(injection.injectedLanguageId, injection.prefix, injection.suffix)
-            }
-        }
-
-        return null
+        return findInjection(psiParameter, Configuration.getInstance().getInjections(JavaLanguageInjectionSupport.JAVA_SUPPORT_ID))
     }
 
     private fun injectionForKotlinCall(argument: KtValueArgument, ktFunction: KtFunction): InjectionInfo? {
         val argumentIndex = (argument.parent as KtValueArgumentList).arguments.indexOf(argument)
         val ktParameter = ktFunction.valueParameters.getOrNull(argumentIndex) ?: return null
 
-        val injections = Configuration.getInstance().getInjections(KOTLIN_SUPPORT_ID)
+        return findInjection(ktParameter, Configuration.getInstance().getInjections(KOTLIN_SUPPORT_ID))
+    }
 
+    private fun findInjection(element: PsiElement?, injections: List<BaseInjection>): InjectionInfo? {
         for (injection in injections) {
-            if (injection.acceptsPsiElement(ktParameter)) {
+            if (injection.acceptsPsiElement(element)) {
                 return InjectionInfo(injection.injectedLanguageId, injection.prefix, injection.suffix)
             }
         }

idea/src/org/jetbrains/kotlin/idea/patterns/KotlinPatterns.kt

@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.renderer.DescriptorRenderer
 object KotlinPatterns: StandardPatterns() {
     @JvmStatic fun psiParameter() = KtParameterPattern()
     @JvmStatic fun psiMethod() = KotlinFunctionPattern()
+    @JvmStatic fun receiver() = KotlinReceiverPattern()
 }
 
 // Methods in this class are used through reflection during pattern construction
@@ -119,3 +120,21 @@ class KtParameterPattern : PsiElementPattern<KtParameter, KtParameterPattern>(Kt
     }
 }
 
+@Suppress("unused")
+class KotlinReceiverPattern : PsiElementPattern<KtTypeReference, KotlinReceiverPattern>(KtTypeReference::class.java) {
+    fun ofMethod(pattern: ElementPattern<Any>): KotlinReceiverPattern {
+        return with(object : PatternConditionPlus<KtTypeReference, KtFunction>("KtReceiverPattern-ofMethod", pattern) {
+            override fun processValues(typeReference: KtTypeReference, context: ProcessingContext?, processor: PairProcessor<KtFunction, ProcessingContext>): Boolean {
+                return processor.process(typeReference.parent as? KtFunction, context)
+            }
+
+            override fun accepts(typeReference: KtTypeReference, context: ProcessingContext?): Boolean {
+                val ktFunction = typeReference.parent as? KtFunction ?: return false
+                if (ktFunction.receiverTypeReference != typeReference) return false
+
+                return super.accepts(typeReference, context)
+            }
+        })
+    }
+}
+

idea/tests/org/jetbrains/kotlin/psi/KotlinStdlibInjectionTest.kt

@@ -41,6 +41,27 @@ class KotlinStdlibInjectionTest : AbstractInjectionTest() {
             RegExpLanguage.INSTANCE.id
     )
 
+    fun testToRegex0() = testInjection(
+            """
+            |val test = "hi<caret>".toRegex()
+            """,
+            RegExpLanguage.INSTANCE.id
+    )
+
+    fun testToRegex1() = testInjection(
+            """
+            |val test = "hi<caret>".toRegex(RegexOption.CANON_EQ)
+            """,
+            RegExpLanguage.INSTANCE.id
+    )
+
+    fun testToRegex2() = testInjection(
+            """
+            |val test = "hi<caret>".toRegex(setOf(RegexOption.LITERAL))
+            """,
+            RegExpLanguage.INSTANCE.id
+    )
+
     private fun testInjection(text: String, languageId: String) {
         testInjectionPresent(text, languageId, false)
     }