Don't use PSI for line number calculation

diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter3/identifiers/LocalVariablesRule.kt

@@ -96,6 +96,11 @@ class LocalVariablesRule(configRules: List<RulesConfig>) : DiktatRule(
         checkLineNumbers(property, firstUsageStatementLine, firstUsageLine = firstUsage.node.getLineNumber(), offset = offset)
     }
 
+    /**
+     * Check declarations, for which the properties are used on the same line.
+     * If properties are used for the first time in the same statement, then they can be declared on consecutive lines
+     * with maybe empty lines in between.
+     */
     @Suppress("TOO_LONG_FUNCTION")
     private fun handleConsecutiveDeclarations(statement: PsiElement, properties: List<KtProperty>) {
         val numLinesAfterLastProp =
@@ -173,6 +178,8 @@ class LocalVariablesRule(configRules: List<RulesConfig>) : DiktatRule(
 
     /**
      * Returns the [KtBlockExpression] with which a property should be compared.
+     * If the usage is in nested block, compared to declaration, then statement from declaration scope, which contains block
+     * with usage, is returned.
      *
      * @return either the line on which the property is used if it is first used in the same scope, or the block in the same scope as declaration
      */

diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/AstNodeUtils.kt

@@ -40,7 +40,6 @@ import com.pinterest.ktlint.core.ast.isLeaf
 import com.pinterest.ktlint.core.ast.isPartOfComment
 import com.pinterest.ktlint.core.ast.isRoot
 import com.pinterest.ktlint.core.ast.isWhiteSpace
-import com.pinterest.ktlint.core.ast.lineNumber
 import com.pinterest.ktlint.core.ast.parent
 import org.jetbrains.kotlin.com.intellij.lang.ASTNode
 import org.jetbrains.kotlin.com.intellij.psi.TokenType
@@ -52,7 +51,6 @@ import org.jetbrains.kotlin.psi.KtAnnotationEntry
 import org.jetbrains.kotlin.psi.KtClass
 import org.jetbrains.kotlin.psi.KtIfExpression
 import org.jetbrains.kotlin.psi.psiUtil.children
-import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.parents
 import org.jetbrains.kotlin.psi.psiUtil.siblings
 import org.slf4j.Logger
@@ -763,18 +761,12 @@ fun ASTNode.hasEqBinaryExpression(): Boolean =
             ?: false
 
 /**
- * Get line number, where this node's content starts. To avoid `ArrayIndexOutOfBoundsException`s we check whether node's maximum offset is less than
- * Document's maximum offset, and calculate line number manually if needed.
+ * Get line number, where this node's content starts.
  *
- * @return line number or null if it cannot be calculated
+ * @return line number
  */
 fun ASTNode.getLineNumber(): Int =
-        psi.containingFile
-            .viewProvider
-            .document
-            ?.takeIf { it.getLineEndOffset(it.lineCount - 1) >= psi.endOffset }
-            ?.let { lineNumber() }
-            ?: calculateLineNumber()
+        calculateLineNumber()
 
 /**
  * This function calculates line number instead of using cached values.

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

@@ -265,6 +265,15 @@ class DiktatSmokeTest : FixTestBase("test/smoke/src/main/kotlin",
         fixAndCompare("KdocFormattingMultilineTagsExpected.kt", "KdocFormattingMultilineTagsTest.kt")
     }
 
+    @Test
+    @Tag("DiktatRuleSetProvider")
+    fun `regression - FP of local variables rule`() {
+        fixAndCompare("LocalVariableWithOffsetExpected.kt", "LocalVariableWithOffsetTest.kt")
+        org.assertj.core.api.Assertions.assertThat(unfixedLintErrors).noneMatch {
+            it.ruleId == "diktat-ruleset:local-variables"
+        }
+    }
+
     companion object {
         private const val DEFAULT_CONFIG_PATH = "../diktat-analysis.yml"
         private val unfixedLintErrors: MutableList<LintError> = mutableListOf()

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

@@ -0,0 +1,9 @@
+package org.cqfn.diktat
+
+override fun boo() {
+    val listTestResult: MutableList<TestResult> = mutableListOf()
+    files.chunked(warnPluginConfig.batchSize ?: 1).map { chunk ->
+        handleTestFile(chunk.map { it.single() }, warnPluginConfig, generalConfig)
+    }.forEach { listTestResult.addAll(it) }
+}
+

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

@@ -0,0 +1,8 @@
+package org.cqfn.diktat
+
+    override fun boo() {
+     val listTestResult: MutableList<TestResult> = mutableListOf()
+    files.chunked(warnPluginConfig.batchSize ?: 1).map { chunk ->
+        handleTestFile(chunk.map { it.single() }, warnPluginConfig, generalConfig)
+    }.forEach { listTestResult.addAll(it) }
+}