JS: fix corner case in when translation (fix crash in KT-22544)

compiler/testData/codegen/box/when/switchOptimizationSingleStatementCase.kt

@@ -0,0 +1,27 @@
+// CHECK_CASES_COUNT: function=test1 count=2
+// CHECK_IF_COUNT: function=test1 count=0
+// CHECK_BREAKS_COUNT: function=test1 count=1
+
+// CHECK_CASES_COUNT: function=test2 count=2
+// CHECK_IF_COUNT: function=test2 count=0
+// CHECK_BREAKS_COUNT: function=test2 count=1
+
+fun test1(v: Int) {
+    when (v) {
+        1, 2 -> Unit
+    }
+}
+
+fun test2(v: Int) {
+    loop@ while(true) {
+        when (v) {
+            1, 2 -> break@loop
+        }
+    }
+}
+
+fun box(): String {
+    test1(1)
+    test2(1)
+    return "OK"
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -21489,6 +21489,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             doTest(fileName);
         }
 
+        @TestMetadata("switchOptimizationSingleStatementCase.kt")
+        public void testSwitchOptimizationSingleStatementCase() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSingleStatementCase.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("switchOptimizationSparse.kt")
         public void testSwitchOptimizationSparse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSparse.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -21489,6 +21489,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("switchOptimizationSingleStatementCase.kt")
+        public void testSwitchOptimizationSingleStatementCase() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSingleStatementCase.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("switchOptimizationSparse.kt")
         public void testSwitchOptimizationSparse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSparse.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -21489,6 +21489,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             doTest(fileName);
         }
 
+        @TestMetadata("switchOptimizationSingleStatementCase.kt")
+        public void testSwitchOptimizationSingleStatementCase() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSingleStatementCase.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("switchOptimizationSparse.kt")
         public void testSwitchOptimizationSparse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSparse.kt");

js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/EmptyStatementElimination.kt

@@ -75,7 +75,8 @@ internal class EmptyStatementElimination(private val root: JsStatement) {
                 for (case in x.cases) {
                     processStatements(case.statements)
                 }
-                if (x.cases.dropLast(1).none { it is JsDefault } && x.cases.dropLast(1).all { it.statements.isEmpty() }) {
+                if (x.cases.lastOrNull() is JsDefault &&
+                    x.cases.dropLast(1).all { it.statements.isEmpty() }) {
                     hasChanges = true
                     val conditionStatement = JsAstUtils.asSyntheticStatement(x.expression)
                     ctx.replaceMe(JsBlock(listOf(conditionStatement) + x.cases.last().statements))

js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/FunctionPostProcessor.kt

@@ -37,7 +37,10 @@ class FunctionPostProcessor(val root: JsFunction) {
 
     fun apply() {
         do {
-            val hasChanges = optimizations.fold(false) { existing, f -> existing or f() }
+            var hasChanges = false
+            for (opt in optimizations) {
+                hasChanges = hasChanges or opt()
+            }
         } while (hasChanges)
     }
 }

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -25251,6 +25251,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             doTest(fileName);
         }
 
+        @TestMetadata("switchOptimizationSingleStatementCase.kt")
+        public void testSwitchOptimizationSingleStatementCase() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSingleStatementCase.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("switchOptimizationSparse.kt")
         public void testSwitchOptimizationSparse() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/when/switchOptimizationSparse.kt");