KT-18040: Enable auto popup when typing after $e. in string template

#KT-18040 fixed

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/confidence/EnableAutopopupInStringTemplate.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2017 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.
+ */
+
+package org.jetbrains.kotlin.idea.completion.confidence
+
+import com.intellij.codeInsight.completion.CompletionConfidence
+import com.intellij.openapi.util.TextRange
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiFile
+import com.intellij.util.ThreeState
+import org.jetbrains.kotlin.psi.KtSimpleNameStringTemplateEntry
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
+import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
+import org.jetbrains.kotlin.psi.psiUtil.prevLeaf
+
+class EnableAutopopupInStringTemplate : CompletionConfidence() {
+    override fun shouldSkipAutopopup(contextElement: PsiElement, psiFile: PsiFile, offset: Int): ThreeState {
+        val stringTemplate = contextElement.prevLeaf()?.getParentOfType<KtSimpleNameStringTemplateEntry>(strict = false) ?: return ThreeState.UNSURE
+        val textRange = TextRange.create(stringTemplate.endOffset, offset)
+        val containsWhitespaces = textRange.substring(psiFile.text).any { it.isWhitespace() }
+        return if (containsWhitespaces) ThreeState.UNSURE else ThreeState.NO
+    }
+}

idea/idea-completion/testData/confidence/AutoPopupInStringTemplate.kt

@@ -0,0 +1,10 @@
+class Bar {
+    val aa = "Some"
+}
+
+fun foo() {
+    val bar = Bar()
+    val y = "$bar.<caret>"
+}
+
+// ELEMENT: aa

idea/idea-completion/testData/confidence/NoAutoPopupInRawStringTemplateAfterNewLine.kt

@@ -0,0 +1,11 @@
+class Bar {
+    val aa = "Some"
+}
+
+fun foo() {
+    val bar = Bar()
+    val y = """$bar.
+a<caret>"""
+}
+
+// NO_LOOKUP

idea/idea-completion/testData/confidence/NoAutoPopupInString.kt

@@ -2,3 +2,4 @@ fun test() {
     "a<caret>"
 }
 
+// NO_LOOKUP

idea/idea-completion/testData/confidence/NoAutoPopupInStringTemplateAfterSpace.kt

@@ -0,0 +1,10 @@
+class Bar {
+    val aa = "Some"
+}
+
+fun foo() {
+    val bar = Bar()
+    val y = "$bar. a<caret>"
+}
+
+// NO_LOOKUP

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/confidence/KotlinConfidenceTest.java

@@ -20,10 +20,13 @@ import com.intellij.codeInsight.CodeInsightSettings;
 import com.intellij.codeInsight.completion.CodeCompletionHandlerBase;
 import com.intellij.codeInsight.completion.CompletionType;
 import com.intellij.codeInsight.completion.LightCompletionTestCase;
+import com.intellij.codeInsight.lookup.LookupElement;
+import com.intellij.codeInsight.lookup.LookupManager;
 import com.intellij.codeInsight.lookup.impl.LookupImpl;
 import com.intellij.openapi.projectRoots.JavaSdk;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.util.ArrayUtil;
 import org.apache.commons.lang.SystemUtils;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.idea.completion.test.CompletionTestUtilKt;
@@ -32,6 +35,7 @@ import org.jetbrains.kotlin.idea.test.TestUtilsKt;
 import org.jetbrains.kotlin.test.InTextDirectivesUtils;
 
 import java.io.File;
+import java.util.List;
 
 public class KotlinConfidenceTest extends LightCompletionTestCase {
     private static final String TYPE_DIRECTIVE_PREFIX = "// TYPE:";
@@ -60,6 +64,18 @@ public class KotlinConfidenceTest extends LightCompletionTestCase {
         doTest();
     }
 
+    public void testAutoPopupInStringTemplate() {
+        doTest();
+    }
+
+    public void testNoAutoPopupInStringTemplateAfterSpace() {
+        doTest();
+    }
+
+    public void testNoAutoPopupInRawStringTemplateAfterNewLine() {
+        doTest();
+    }
+
     @Override
     protected void setUp() throws Exception {
         super.setUp();
@@ -83,23 +99,31 @@ public class KotlinConfidenceTest extends LightCompletionTestCase {
 
         try {
             configureByFile(getBeforeFileName());
-            String typeText = getTypeTextFromFile();
-            if (typeText != null) {
-                type(typeText);
-                checkResultByFile(getAfterFileName());
+            String text = getEditor().getDocument().getText();
+            String typeText = getTypeText(text);
+            List<String> expectedElements = InTextDirectivesUtils.findLinesWithPrefixesRemoved(text, "// ELEMENT:");
+            boolean noLookup = InTextDirectivesUtils.isDirectiveDefined(text, "// NO_LOOKUP");
+
+            assertFalse("Can't both expect lookup elements and no lookup", !expectedElements.isEmpty() && noLookup);
+
+            if (noLookup) {
+                assertNull("Expected no lookup", getLookup());
+                return;
             }
-            else {
-                LookupImpl lookup = getLookup();
-                assertNull("No completion auto-popup expected", lookup);
+            else if (!expectedElements.isEmpty()) {
+                assertContainsItems(ArrayUtil.toStringArray(expectedElements));
+                return;
             }
+            assertNotNull("You must type something, use // TYPE:", typeText);
+            type(typeText);
+            checkResultByFile(getAfterFileName());
         }
         finally {
             CodeInsightSettings.getInstance().SELECT_AUTOPOPUP_SUGGESTIONS_BY_CHARS = completeByChars;
         }
     }
 
-    protected static String getTypeTextFromFile() {
-        String text = getEditor().getDocument().getText();
+    protected static String getTypeText(String text) {
 
         String[] directives = InTextDirectivesUtils.findArrayWithPrefixes(text, TYPE_DIRECTIVE_PREFIX);
         if (directives.length == 0) return null;
@@ -131,5 +155,9 @@ public class KotlinConfidenceTest extends LightCompletionTestCase {
     protected void complete() {
         new CodeCompletionHandlerBase(CompletionType.BASIC, false, true, true).invokeCompletion(
                 getProject(), getEditor(), 0, false, false);
+
+        LookupImpl lookup = (LookupImpl) LookupManager.getActiveLookup(myEditor);
+        myItems = lookup == null ? null : lookup.getItems().toArray(LookupElement.EMPTY_ARRAY);
+        myPrefix = lookup == null ? null : lookup.itemPattern(lookup.getItems().get(0));
     }
 }

idea/src/META-INF/plugin.xml

@@ -491,6 +491,7 @@
     <completion.confidence language="kotlin"
                            implementationClass="org.jetbrains.kotlin.idea.completion.confidence.UnfocusedPossibleFunctionParameter"/>
     <completion.confidence language="kotlin" implementationClass="com.intellij.codeInsight.completion.AlwaysFocusLookup" order="last"/>
+    <completion.confidence language="kotlin" implementationClass="org.jetbrains.kotlin.idea.completion.confidence.EnableAutopopupInStringTemplate"/>
     <completion.confidence language="kotlin" implementationClass="com.intellij.codeInsight.completion.SkipAutopopupInStrings"/>
 
     <lookup.charFilter implementation="org.jetbrains.kotlin.idea.completion.KotlinCompletionCharFilter"/>