NPE in NewlinesRule.kt

### What's done: (#1853) - Fixed NPE on test Closes #1779
saveourtool · Dec 11, 2023 · 3059a40 · 3059a40
1 parent 65d5558
commit 3059a40
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Showing 2 changed files with 21 additions and 8 deletions.
diff --git a/...rules/src/main/kotlin/com/saveourtool/diktat/ruleset/rules/chapter3/files/NewlinesRule.kt b/...rules/src/main/kotlin/com/saveourtool/diktat/ruleset/rules/chapter3/files/NewlinesRule.kt
@@ -510,22 +510,21 @@ class NewlinesRule(configRules: List<RulesConfig>) : DiktatRule(
             }
         }
 
-    @Suppress("AVOID_NULL_CHECKS")
     private fun handleValueParameterList(node: ASTNode, entryType: String) = node
         .children()
         .filter {
-            (it.elementType == COMMA && !it.treeNext.isNewLineNode()) ||
+            val isNewLineNext = it.treeNext?.isNewLineNode() ?: false
+            val isNewLinePrev = it.treePrev?.isNewLineNode() ?: false
+            (it.elementType == COMMA && !isNewLineNext) ||
                     // Move RPAR to the new line
-                    (it.elementType == RPAR && it.treePrev.elementType != COMMA && !it.treePrev.isNewLineNode())
+                    (it.elementType == RPAR && it.treePrev?.elementType != COMMA && !isNewLinePrev)
         }
         .toList()
         .takeIf { it.isNotEmpty() }
         ?.let { invalidCommas ->
-            val warnText = if (node.getParentIdentifier() != null) {
+            val warnText = node.getParentIdentifier()?.let {
                 "$entryType should be placed on different lines in declaration of <${node.getParentIdentifier()}>"
-            } else {
-                "$entryType should be placed on different lines"
-            }
+            } ?: "$entryType should be placed on different lines"
             WRONG_NEWLINES.warnAndFix(configRules, emitWarn, isFixMode,
                 warnText, node.startOffset, node) {
                 invalidCommas.forEach { commaOrRpar ->
@@ -535,7 +534,7 @@ class NewlinesRule(configRules: List<RulesConfig>) : DiktatRule(
                             commaOrRpar.appendNewlineMergingWhiteSpace(nextWhiteSpace, nextWhiteSpace.treeNext)
                         } ?: commaOrRpar.treeNext?.treeParent?.appendNewlineMergingWhiteSpace(nextWhiteSpace, commaOrRpar.treeNext)
                     } else {
-                        commaOrRpar.treeParent.appendNewlineMergingWhiteSpace(nextWhiteSpace, commaOrRpar)
+                        commaOrRpar.treeParent?.appendNewlineMergingWhiteSpace(nextWhiteSpace, commaOrRpar)
                     }
                 }
             }

diff --git a/...les/src/test/kotlin/com/saveourtool/diktat/ruleset/chapter3/files/NewlinesRuleWarnTest.kt b/...les/src/test/kotlin/com/saveourtool/diktat/ruleset/chapter3/files/NewlinesRuleWarnTest.kt
@@ -1158,6 +1158,20 @@ class NewlinesRuleWarnTest : LintTestBase(::NewlinesRule) {
         )
     }
 
+    @Test
+    @Tag(WarningNames.WRONG_NEWLINES)
+    fun `shouldn't fall with NPE`() {
+        lintMethod(
+            """
+                |val TEST_FUNC = { _: Int, _: Set<Int>, _: Int, ->
+                |}
+            """.trimMargin(),
+            DiktatError(1, 19, ruleId, "${WRONG_NEWLINES.warnText()} " +
+                    "first parameter should be placed on a separate line or all other parameters should be aligned with it in declaration of <null>", true),
+            DiktatError(1, 19, ruleId, "${WRONG_NEWLINES.warnText()} value parameters should be placed on different lines", true),
+            )
+    }
+
     @Test
     @Tag(WarningNames.WRONG_NEWLINES)
     fun `not complaining on fun without return type`() {