KT-18674 Join Lines should join strings (#1305)

* Join Lines should join strings #KT-18674 Fixed

* #KT-18674 Fixed

idea/src/META-INF/plugin.xml

@@ -727,6 +727,7 @@
     <joinLinesHandler implementation="org.jetbrains.kotlin.idea.joinLines.JoinDeclarationAndAssignmentHandler"/>
     <joinLinesHandler implementation="org.jetbrains.kotlin.idea.joinLines.JoinBlockIntoSingleStatementHandler"/>
     <joinLinesHandler implementation="org.jetbrains.kotlin.idea.joinLines.JoinStatementsAddSemicolonHandler"/>
+    <joinLinesHandler implementation="org.jetbrains.kotlin.idea.joinLines.JoinToStringTemplateHandler"/>
 
     <targetElementEvaluator
         language="kotlin"

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertToStringTemplateIntention.kt

@@ -57,7 +57,7 @@ open class ConvertToStringTemplateIntention : SelfTargetingOffsetIndependentInte
         }
 
         @JvmStatic
-        protected fun buildReplacement(expression: KtBinaryExpression): KtStringTemplateExpression {
+        fun buildReplacement(expression: KtBinaryExpression): KtStringTemplateExpression {
             val rightText = buildText(expression.right, false)
             return fold(expression.left, rightText, KtPsiFactory(expression))
         }
@@ -130,7 +130,7 @@ open class ConvertToStringTemplateIntention : SelfTargetingOffsetIndependentInte
             return "\${$expressionText}"
         }
 
-        private fun isApplicableToNoParentCheck(expression: KtBinaryExpression): Boolean {
+        fun isApplicableToNoParentCheck(expression: KtBinaryExpression): Boolean {
             if (expression.operationToken != KtTokens.PLUS) return false
             val expressionType = expression.analyze(BodyResolveMode.PARTIAL).getType(expression)
             if (!KotlinBuiltIns.isString(expressionType)) return false

idea/src/org/jetbrains/kotlin/idea/joinLines/JoinToStringTemplateHandler.kt

@@ -0,0 +1,50 @@
+/*
+ * 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.joinLines
+
+import com.intellij.codeInsight.editorActions.JoinRawLinesHandlerDelegate
+import com.intellij.openapi.editor.Document
+import com.intellij.psi.PsiFile
+import org.jetbrains.kotlin.idea.intentions.ConvertToStringTemplateIntention
+import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.psi.KtBinaryExpression
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtStringTemplateExpression
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
+
+class JoinToStringTemplateHandler : JoinRawLinesHandlerDelegate {
+    override fun tryJoinRawLines(document: Document, file: PsiFile, start: Int, end: Int): Int {
+        if (file !is KtFile) return -1
+
+        if (start == 0) return -1
+        val c = document.charsSequence[start]
+        val index = if (c == '\n') start - 1 else start
+
+        val plus = file.findElementAt(index)?.takeIf { it.node?.elementType == KtTokens.PLUS } ?: return -1
+        val expression = (plus.parent.parent as? KtBinaryExpression) ?: return -1
+        val left = expression.left ?: return -1
+        val right = expression.right ?: return -1
+        if (left !is KtStringTemplateExpression || right !is KtStringTemplateExpression) return -1
+        if (!ConvertToStringTemplateIntention.isApplicableToNoParentCheck(expression)) return -1
+
+        val offset = left.endOffset - 1
+        expression.replace(ConvertToStringTemplateIntention.buildReplacement(expression))
+        return offset
+    }
+
+    override fun tryJoinLines(document: Document, file: PsiFile, start: Int, end: Int): Int = -1
+}

idea/testData/joinLines/stringTemplate/firstLineVariable.kt

@@ -0,0 +1,5 @@
+fun test() {
+    val foo = "1"
+    val s = foo +<caret>
+            "bar"
+}

idea/testData/joinLines/stringTemplate/firstLineVariable.kt.after

@@ -0,0 +1,4 @@
+fun test() {
+    val foo = "1"
+    val s = foo +<caret> "bar"
+}

idea/testData/joinLines/stringTemplate/secondLineVariable.kt

@@ -0,0 +1,5 @@
+fun test() {
+    val foo = "1"
+    val s = "bar" +<caret>
+            foo
+}

idea/testData/joinLines/stringTemplate/secondLineVariable.kt.after

@@ -0,0 +1,4 @@
+fun test() {
+    val foo = "1"
+    val s = "bar" +<caret> foo
+}

idea/testData/joinLines/stringTemplate/simple.kt

@@ -0,0 +1,4 @@
+fun test() {
+    val s = "foo" +<caret>
+            "bar"
+}

idea/testData/joinLines/stringTemplate/simple.kt.after

@@ -0,0 +1,3 @@
+fun test() {
+    val s = "foo<caret>bar"
+}

idea/testData/joinLines/stringTemplate/threeLines.kt

@@ -0,0 +1,5 @@
+fun test() {
+    val s = "foo" +<caret>
+            "bar" +
+            "baz"
+}

idea/testData/joinLines/stringTemplate/threeLines.kt.after

@@ -0,0 +1,4 @@
+fun test() {
+    val s = "foo<caret>bar" +
+            "baz"
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/declarations/JoinLinesTestGenerated.java

@@ -425,4 +425,37 @@ public class JoinLinesTestGenerated extends AbstractJoinLinesTest {
             doTest(fileName);
         }
     }
+
+    @TestMetadata("idea/testData/joinLines/stringTemplate")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class StringTemplate extends AbstractJoinLinesTest {
+        public void testAllFilesPresentInStringTemplate() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/joinLines/stringTemplate"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("firstLineVariable.kt")
+        public void testFirstLineVariable() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/joinLines/stringTemplate/firstLineVariable.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("secondLineVariable.kt")
+        public void testSecondLineVariable() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/joinLines/stringTemplate/secondLineVariable.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/joinLines/stringTemplate/simple.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("threeLines.kt")
+        public void testThreeLines() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/joinLines/stringTemplate/threeLines.kt");
+            doTest(fileName);
+        }
+    }
 }