Bugfix. When changing indentation of multiline string, all lines shou…

…ld be changed (#670)

* bugfix/indentation-multiline-string(#574)

### What's done:
  * Fixed bugs

diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/files/IndentationRule.kt

@@ -8,6 +8,7 @@ import org.cqfn.diktat.common.config.rules.RulesConfig
 import org.cqfn.diktat.common.config.rules.getRuleConfig
 import org.cqfn.diktat.ruleset.constants.EmitType
 import org.cqfn.diktat.ruleset.constants.Warnings.WRONG_INDENTATION
+import org.cqfn.diktat.ruleset.utils.getAllChildrenWithType
 import org.cqfn.diktat.ruleset.utils.getAllLeafsWithSpecificType
 import org.cqfn.diktat.ruleset.utils.getFilePath
 import org.cqfn.diktat.ruleset.utils.indentBy
@@ -26,16 +27,19 @@ import org.cqfn.diktat.ruleset.utils.leaveOnlyOneNewLine
 import org.cqfn.diktat.ruleset.utils.log
 
 import com.pinterest.ktlint.core.Rule
+import com.pinterest.ktlint.core.ast.ElementType.CALL_EXPRESSION
 import com.pinterest.ktlint.core.ast.ElementType.DOT_QUALIFIED_EXPRESSION
 import com.pinterest.ktlint.core.ast.ElementType.ELSE
 import com.pinterest.ktlint.core.ast.ElementType.FILE
 import com.pinterest.ktlint.core.ast.ElementType.LBRACE
 import com.pinterest.ktlint.core.ast.ElementType.LBRACKET
+import com.pinterest.ktlint.core.ast.ElementType.LITERAL_STRING_TEMPLATE_ENTRY
 import com.pinterest.ktlint.core.ast.ElementType.LPAR
 import com.pinterest.ktlint.core.ast.ElementType.RBRACE
 import com.pinterest.ktlint.core.ast.ElementType.RBRACKET
 import com.pinterest.ktlint.core.ast.ElementType.RPAR
 import com.pinterest.ktlint.core.ast.ElementType.SAFE_ACCESS_EXPRESSION
+import com.pinterest.ktlint.core.ast.ElementType.STRING_TEMPLATE
 import com.pinterest.ktlint.core.ast.ElementType.THEN
 import com.pinterest.ktlint.core.ast.ElementType.WHITE_SPACE
 import com.pinterest.ktlint.core.ast.visit
@@ -188,11 +192,48 @@ class IndentationRule(private val configRules: List<RulesConfig>) : Rule("indent
         if (checkResult?.isCorrect != true && expectedIndent != indentError.actual) {
             WRONG_INDENTATION.warnAndFix(configRules, emitWarn, isFixMode, "expected $expectedIndent but was ${indentError.actual}",
                 whiteSpace.startOffset + whiteSpace.text.lastIndexOf('\n') + 1, whiteSpace.node) {
+                checkStringLiteral(whiteSpace, expectedIndent)
                 whiteSpace.node.indentBy(expectedIndent)
             }
         }
     }
 
+    /**
+     * Checks if it is triple-quoted string template with trimIndent() or trimMargin() function.
+     */
+    private fun checkStringLiteral(whiteSpace: PsiWhiteSpace, expectedIndent: Int) {
+        val nextNode = whiteSpace.node.treeNext
+        if (nextNode != null &&
+                nextNode.elementType == DOT_QUALIFIED_EXPRESSION &&
+                nextNode.firstChildNode.elementType == STRING_TEMPLATE &&
+                nextNode.firstChildNode.text.startsWith("\"\"\"") &&
+                nextNode.findChildByType(CALL_EXPRESSION)?.text?.let {
+                    it == "trimIndent()" ||
+                            it == "trimMargin()"
+                } == true) {
+            fixStringLiteral(whiteSpace, expectedIndent)
+        }
+    }
+
+    /**
+     * If it is triple-quoted string template we need to indent all its parts
+     */
+    private fun fixStringLiteral(whiteSpace: PsiWhiteSpace, expectedIndent: Int) {
+        val textIndent = " ".repeat(expectedIndent + INDENT_SIZE)
+        val templateEntries = whiteSpace.node.treeNext.firstChildNode.getAllChildrenWithType(LITERAL_STRING_TEMPLATE_ENTRY)
+        templateEntries.forEach {
+            if (!it.text.contains("\n") && it.text.isNotBlank()) {
+                (it.firstChildNode as LeafPsiElement).rawReplaceWithText(textIndent + it.firstChildNode.text.trim())
+            }
+        }
+        (templateEntries.last().firstChildNode as LeafPsiElement)
+            .rawReplaceWithText(" ".repeat(expectedIndent) + templateEntries
+                .last()
+                .firstChildNode
+                .text
+                .trim())
+    }
+
     private fun ASTNode.getExceptionalIndentInitiator() = treeParent.let { parent ->
         when (parent.psi) {
             // fixme: custom logic for determining exceptional indent initiator, should be moved elsewhere

diktat-rules/src/test/kotlin/org/cqfn/diktat/ruleset/smoke/DiktatSmokeTest.kt

@@ -95,6 +95,12 @@ class DiktatSmokeTest : FixTestBase("test/smoke/src/main/kotlin",
         fixAndCompare("DefaultPackageExpected.kt", "DefaultPackageTest.kt")
     }
 
+    @Test
+    @Tag("DiktatRuleSetProvider")
+    fun `smoke test #6`() {
+        fixAndCompare("Example6Expected.kt", "Example6Test.kt")
+    }
+
     @Test
     @Tag("DiktatRuleSetProvider")
     fun `smoke test #5`() {

diktat-rules/src/test/resources/test/smoke/src/main/kotlin/Example6Expected.kt

@@ -0,0 +1,20 @@
+package org.cqfn.diktat
+
+val foo =
+        """
+            some
+            cool
+            text
+        """.trimIndent()
+
+val bar =
+        """
+            | some
+            | text
+        """.trimMargin()
+
+val text =
+        """
+       x 
+    """
+

diktat-rules/src/test/resources/test/smoke/src/main/kotlin/Example6Test.kt

@@ -0,0 +1,20 @@
+package org.cqfn.diktat
+
+val foo =
+    """
+        some
+        cool
+        text
+    """.trimIndent()
+
+val bar =
+    """
+        | some
+        | text
+    """.trimMargin()
+
+val text =
+    """
+       x 
+    """
+