Bugfix for fi mode of AVOID_NULL_CHECK

### What's done: * Added a check for assignment operator when deciding if to put run block or not * Added tests (#1293)
saveourtool · Oct 27, 2022 · 8bed41d · 8bed41d
1 parent c04695e
commit 8bed41d
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Showing 2 changed files with 28 additions and 18 deletions.
diff --git a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter4/NullChecksRule.kt b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter4/NullChecksRule.kt
@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.com.intellij.psi.tree.IElementType
 import org.jetbrains.kotlin.psi.KtBinaryExpression
 import org.jetbrains.kotlin.psi.KtBlockExpression
 import org.jetbrains.kotlin.psi.KtIfExpression
+import org.jetbrains.kotlin.psi.KtPsiUtil
 import org.jetbrains.kotlin.psi.psiUtil.blockExpressionsOrSingle
 
 /**
@@ -119,9 +120,10 @@ class NullChecksRule(configRules: List<RulesConfig>) : DiktatRule(
     }
 
     @Suppress("UnsafeCallOnNullableType", "TOO_LONG_FUNCTION")
-    private fun fixNullInIfCondition(condition: ASTNode,
-                                     binaryExpression: KtBinaryExpression,
-                                     isEqualToNull: Boolean
+    private fun fixNullInIfCondition(
+        condition: ASTNode,
+        binaryExpression: KtBinaryExpression,
+        isEqualToNull: Boolean
     ) {
         val variableName = binaryExpression.left!!.text
         val thenFromExistingCode = condition.extractLinesFromBlock(THEN)
@@ -138,13 +140,24 @@ class NullChecksRule(configRules: List<RulesConfig>) : DiktatRule(
         } else {
             elseFromExistingCode
         }
-        val numberOfStatementsInElseBlock = if (isEqualToNull) {
-            (condition.treeParent.psi as KtIfExpression).then?.blockExpressionsOrSingle()?.count() ?: 0
-        } else {
-            (condition.treeParent.psi as KtIfExpression).`else`?.blockExpressionsOrSingle()?.count() ?: 0
-        }
 
-        val elseEditedCodeLines = getEditedElseCodeLines(elseCodeLines, numberOfStatementsInElseBlock)
+        val (numberOfStatementsInElseBlock, isAssignmentInNewElseBlock) = (condition.treeParent.psi as KtIfExpression)
+            .let {
+                if (isEqualToNull) {
+                    it.then
+                } else {
+                    it.`else`
+                }
+            }
+            ?.blockExpressionsOrSingle()
+            ?.let { elements ->
+                elements.count() to elements.any {
+                        element -> KtPsiUtil.isAssignment(element)
+                }
+            }
+            ?: Pair(0, false)
+
+        val elseEditedCodeLines = getEditedElseCodeLines(elseCodeLines, numberOfStatementsInElseBlock, isAssignmentInNewElseBlock)
         val thenEditedCodeLines = getEditedThenCodeLines(variableName, thenCodeLines, elseEditedCodeLines)
 
         val text = "$thenEditedCodeLines $elseEditedCodeLines"
@@ -153,11 +166,15 @@ class NullChecksRule(configRules: List<RulesConfig>) : DiktatRule(
         ifNode.treeParent.replaceChild(ifNode, tree)
     }
 
-    private fun getEditedElseCodeLines(elseCodeLines: List<String>?, numberOfStatementsInElseBlock: Int): String = when {
+    private fun getEditedElseCodeLines(
+        elseCodeLines: List<String>?,
+        numberOfStatementsInElseBlock: Int,
+        isAssignment: Boolean,
+    ): String = when {
         // else { "null"/empty } -> ""
         elseCodeLines == null || elseCodeLines.singleOrNull() == "null" -> ""
         // else { bar() } -> ?: bar()
-        numberOfStatementsInElseBlock == 1 && elseCodeLines.singleOrNull()?.hasAssignment() != true -> "?: ${elseCodeLines.joinToString(postfix = "\n", separator = "\n")}"
+        numberOfStatementsInElseBlock == 1 && !isAssignment -> "?: ${elseCodeLines.joinToString(postfix = "\n", separator = "\n")}"
         // else { ... } -> ?: run { ... }
         else -> getDefaultCaseElseCodeLines(elseCodeLines)
     }

diff --git a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/StringUtils.kt b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/utils/StringUtils.kt
@@ -12,8 +12,6 @@ internal const val SPACE = ' '
 
 internal const val TAB = '\t'
 
-private const val REGEX_FOR_ASSIGNMENT_DETECTION = "[^=]+=[^=]+"
-
 @Suppress("VARIABLE_NAME_INCORRECT_FORMAT")
 val JAVA = arrayOf("abstract", "assert", "boolean",
     "break", "byte", "case", "catch", "char", "class", "const",
@@ -39,11 +37,6 @@ val KOTLIN = KtTokens.KEYWORDS
  */
 val loggerPropertyRegex = "(?iu)^log(?:ger)?$".toRegex()
 
-/**
- * @return true if this String includes assignment operator, false otherwise
- */
-fun String.hasAssignment(): Boolean = contains(REGEX_FOR_ASSIGNMENT_DETECTION.toRegex())
-
 /**
  * @return whether [this] string represents a Java keyword
  */