Add SIR builder and printer for classes #KT-65905 fixed

Merge-request: KT-MR-14478
Merged-by: Artem Olkov <artem.olkov@jetbrains.com>

native/swift/sir-printer/src/org/jetbrains/sir/printer/SirAsSwiftSourcesPrinter.kt

@@ -41,9 +41,22 @@ public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVi
         println("import ${import.moduleName}")
     }
 
+    override fun visitClass(klass: SirClass): Unit = with(printer) {
+        printVisibility(klass)
+        println(
+            "class ",
+            klass.name.swiftIdentifier,
+            " {"
+        )
+        withIndent {
+            klass.acceptChildren(this@SirAsSwiftSourcesPrinter)
+        }
+        println("}")
+    }
+
     override fun visitVariable(variable: SirVariable): Unit = with(printer) {
+        printVisibility(variable)
         print(
-            variable.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " } ?: "",
             if (variable.isStatic) "static " else "",
             "var ",
             variable.name.swiftIdentifier,
@@ -82,8 +95,8 @@ public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVi
 
     override fun visitFunction(function: SirFunction): Unit = with(printer) {
         function.documentation?.let { println(it) }
+        printVisibility(function)
         print(
-            function.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " } ?: "",
             if (function.isStatic) {
                 "static "
             } else {
@@ -121,8 +134,8 @@ public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVi
     }
 
     override fun visitEnum(enum: SirEnum): Unit = with(printer) {
+        printVisibility(enum)
         println(
-            enum.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " } ?: "",
             "enum ",
             enum.name.swiftIdentifier,
             " {"
@@ -167,4 +180,10 @@ private val SirNamedDeclaration.swiftFqName: String
 
 private val simpleIdentifierRegex = Regex("[_a-zA-Z][_a-zA-Z0-9]*")
 
-private val String.swiftIdentifier get() = if (simpleIdentifierRegex.matches(this)) this else "`$this`"
+private val String.swiftIdentifier get() = if (simpleIdentifierRegex.matches(this)) this else "`$this`"
+
+internal fun SmartPrinter.printVisibility(decl: SirDeclaration) {
+    print(
+        decl.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " } ?: ""
+    )
+}

native/swift/sir-printer/testData/empty_class.golden.swift

@@ -0,0 +1,2 @@
+public class Foo {
+}

native/swift/sir-printer/testData/empty_class_inside_class.golden.swift

@@ -0,0 +1,4 @@
+public class OUTER_CLASS {
+    public class INNER_CLASS {
+    }
+}

native/swift/sir-printer/testData/empty_class_inside_enum.golden.swift

@@ -0,0 +1,4 @@
+public enum MyEnum {
+    public class Foo {
+    }
+}

native/swift/sir-printer/tests/org/jetbrains/kotlin/sir/printer/SirAsSwiftSourcesPrinterTests.kt

@@ -6,6 +6,8 @@
 package org.jetbrains.kotlin.sir.printer
 
 import org.jetbrains.kotlin.sir.*
+import org.jetbrains.kotlin.sir.builder.buildClass
+import org.jetbrains.kotlin.sir.builder.buildEnum
 import org.jetbrains.kotlin.sir.builder.buildFunction
 import org.jetbrains.kotlin.sir.builder.buildModule
 import org.jetbrains.kotlin.sir.util.SirSwiftModule
@@ -275,6 +277,72 @@ class SirAsSwiftSourcesPrinterTests {
         )
     }
 
+    @Test
+    fun `should print empty class`() {
+
+        val module = buildModule {
+            name = "Test"
+            declarations.add(
+                buildClass {
+                    origin = SirOrigin.Unknown
+                    visibility = SirVisibility.PUBLIC
+                    name = "Foo"
+                }
+            )
+        }
+
+        runTest(
+            module,
+            "testData/empty_class"
+        )
+    }
+
+    @Test
+    fun `should print empty class inside enum`() {
+
+        val module = buildModule {
+            name = "Test"
+            declarations.add(
+                buildEnum {
+                    origin = SirOrigin.Unknown
+                    name = "MyEnum"
+
+                    declarations.add(
+                        buildClass {
+                            origin = SirOrigin.Unknown
+                            visibility = SirVisibility.PUBLIC
+                            name = "Foo"
+                        })})}
+
+        runTest(
+            module,
+            "testData/empty_class_inside_enum"
+        )
+    }
+
+    @Test
+    fun `should print empty class inside class`() {
+
+        val module = buildModule {
+            name = "Test"
+            declarations.add(
+                buildClass {
+                    origin = SirOrigin.Unknown
+                    name = "OUTER_CLASS"
+
+                    declarations.add(
+                        buildClass {
+                            origin = SirOrigin.Unknown
+                            visibility = SirVisibility.PUBLIC
+                            name = "INNER_CLASS"
+                        })})}
+
+        runTest(
+            module,
+            "testData/empty_class_inside_class"
+        )
+    }
+
     private fun runTest(module: SirModule, goldenDataFile: String) {
         val expectedSwiftSrc = File(KtTestUtil.getHomeDirectory()).resolve("$goldenDataFile.golden.swift")