[JS IR] Add an explicit toString() call for concatenating Char values

^KT-59718 Fixed

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/JsStringConcatenationLowering.kt

@@ -9,12 +9,15 @@ import org.jetbrains.kotlin.backend.common.CommonBackendContext
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.util.overrides
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+import org.jetbrains.kotlin.utils.filterIsInstanceAnd
 
 class JsStringConcatenationLowering(val context: CommonBackendContext) : FileLoweringPass {
     override fun lower(irFile: IrFile) {
@@ -30,7 +33,9 @@ private class JsStringConcatenationTransformer(val context: CommonBackendContext
             // See KT-39891
             if (this !is IrSimpleType) return false
             return when (classifier.signature) {
-                IdSignatureValues.any, IdSignatureValues.comparable, IdSignatureValues.number, IdSignatureValues._long -> true
+                IdSignatureValues.any, IdSignatureValues.comparable, IdSignatureValues.number,
+                IdSignatureValues._long, IdSignatureValues._char
+                -> true
                 else -> false
             }
         }
@@ -43,7 +48,15 @@ private class JsStringConcatenationTransformer(val context: CommonBackendContext
                 extensionReceiver = this@explicitlyConvertedToString
             }
         } else {
-            JsIrBuilder.buildCall(context.ir.symbols.memberToString).apply {
+            val anyToStringMethodSymbol = context.ir.symbols.memberToString
+            val toStringMethodSymbol = type.classOrNull?.let {
+                val toStringMethods = it.owner.declarations.filterIsInstanceAnd<IrSimpleFunction> { f ->
+                    f.overrides(anyToStringMethodSymbol.owner)
+                }
+                toStringMethods.singleOrNull()?.symbol
+            } ?: anyToStringMethodSymbol
+
+            JsIrBuilder.buildCall(toStringMethodSymbol).apply {
                 dispatchReceiver = this@explicitlyConvertedToString
             }
         }

js/js.translator/testData/box/char/charNoBoxing.kt

@@ -1,42 +1,98 @@
+// KJS_WITH_FULL_RUNTIME
+
 fun getC(c: Char) = c
 inline fun getCInline(c: Char) = c
 
-// CHECK_NEW_COUNT: function=testNonInline1 count=0
-fun testNonInline1(a: Char, b: Char) : Boolean {
+// CHECK_NEW_COUNT: function=testNonInlineEquals1 count=0
+fun testNonInlineEquals1(a: Char, b: Char) : Boolean {
     return getC(a) == getC(b)
 }
 
-// CHECK_NEW_COUNT: function=testNonInline2 count=0
-fun testNonInline2(a: Char, b: Char) : Boolean {
+// CHECK_NEW_COUNT: function=testNonInlineEquals2 count=0
+fun testNonInlineEquals2(a: Char, b: Char) : Boolean {
     val a1 = getC(a)
     val b1 = getC(b)
     return a1 == b1
 }
 
-// CHECK_NEW_COUNT: function=testInline1 count=0
-fun testInline1(a: Char, b: Char) : Boolean {
+// CHECK_NEW_COUNT: function=testInlineEquals1 count=0
+fun testInlineEquals1(a: Char, b: Char) : Boolean {
     return getCInline(a) == getCInline(b)
 }
 
-// CHECK_NEW_COUNT: function=testInline2 count=0
-fun testInline2(a: Char, b: Char) : Boolean {
+// CHECK_NEW_COUNT: function=testInlineEquals2 count=0
+fun testInlineEquals2(a: Char, b: Char) : Boolean {
     val a1 = getCInline(a)
     val b1 = getCInline(b)
     return a1 == b1
 }
 
+// CHECK_NEW_COUNT: function=testStringAppend1 count=0
+fun testStringAppend1(s1: String, b: Char, s2: String) : Boolean {
+    val s = s1 + b
+    return s == s2
+}
+
+// CHECK_NEW_COUNT: function=testStringAppend2 count=0
+fun testStringAppend2(a: Char, s1: String, s2: String) : Boolean {
+    val s = a + s1
+    return s == s2
+}
+
+// CHECK_NEW_COUNT: function=testStringAppendInline1 count=0
+fun testStringAppendInline1(s1: String, b: Char, s2: String) : Boolean {
+    val s = s1 + getCInline(b)
+    return s == s2
+}
+
+// CHECK_NEW_COUNT: function=testStringAppendInline2 count=0
+fun testStringAppendInline2(a: Char, s1: String, s2: String) : Boolean {
+    val s = getCInline(a) + s1
+    return s == s2
+}
+
+// CHECK_NEW_COUNT: function=testStringBuild count=0
+fun testStringBuild(s1: String, b: Char, s2: String) : Boolean {
+    val s = "$s1 $b "
+    return s == s2
+}
+
+// CHECK_NEW_COUNT: function=testStringBuildInline count=0
+fun testStringBuildInline(s1: String, b: Char, s2: String) : Boolean {
+    val s = "$s1 ${getCInline(b)} "
+    return s == s2
+}
+
 fun box(): String {
-    if (!testNonInline1('a', 'a')) {
-        return "Fail testNonInline1"
+    if (!testNonInlineEquals1('a', 'a')) {
+        return "Fail testNonInlineEquals1"
     }
-    if (!testNonInline2('b', 'b')) {
-        return "Fail testNonInline2"
+    if (!testNonInlineEquals2('b', 'b')) {
+        return "Fail testNonInlineEquals2"
     }
-    if (!testInline1('c', 'c')) {
-        return "Fail testInline1"
+    if (!testInlineEquals1('c', 'c')) {
+        return "Fail testInlineEquals1"
     }
-    if (!testInline2('d', 'd')) {
-        return "Fail testInline2"
+    if (!testInlineEquals2('d', 'd')) {
+        return "Fail testInlineEquals2"
+    }
+    if (!testStringAppend1("hello", 'x', "hellox")) {
+        return "Fail testStringAppend1"
+    }
+    if (!testStringAppend2('x', "hello", "xhello")) {
+        return "Fail testStringAppend2"
+    }
+    if (!testStringAppendInline1("hello", 'x', "hellox")) {
+        return "Fail testStringAppendInline1"
+    }
+    if (!testStringAppendInline2('x', "hello", "xhello")) {
+        return "Fail testStringAppendInline2"
+    }
+    if (!testStringBuild("hello", 'x', "hello x ")) {
+        return "Fail testStringBuild"
+    }
+    if (!testStringBuildInline("hello", 'x', "hello x ")) {
+        return "Fail testStringBuildInline"
     }
     return "OK"
 }