fix compilation for markers with empty bodies in Jupyter

core/generated-sources/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/codeGen/CodeGeneratorImpl.kt

@@ -226,8 +226,6 @@ internal open class ExtensionsCodeGeneratorImpl(
 
     private fun String.removeQuotes() = this.removeSurrounding("`")
 
-    private fun generateExtensionProperties(markers: List<Marker>) = markers.map { generateExtensionProperties(it) }
-
     private fun generatePropertyCode(
         marker: IsolatedMarker,
         shortMarkerName: String,
@@ -430,11 +428,6 @@ internal class CodeGeneratorImpl(typeRendering: TypeRenderingStrategy = FullyQua
         return CodeGenResult(code, context.generatedMarkers)
     }
 
-    private fun generateInterfaces(
-        schemas: List<Marker>,
-        fields: Boolean,
-    ) = schemas.map { generateInterface(it, fields) }
-
     private fun generateInterface(
         marker: Marker,
         fields: Boolean,
@@ -483,7 +476,7 @@ internal class CodeGeneratorImpl(typeRendering: TypeRenderingStrategy = FullyQua
                 append("\n}")
             }
         } else {
-            ""
+            " { }"
         }
         resultDeclarations.add(header + baseInterfacesDeclaration + body)
         return resultDeclarations.join()

core/generated-sources/src/test/kotlin/org/jetbrains/kotlinx/dataframe/codeGen/CodeGenerationTests.kt

@@ -60,7 +60,7 @@ class CodeGenerationTests : BaseTest() {
         val typeName = ReplCodeGeneratorImpl.markerInterfacePrefix
         val expectedDeclaration = """
             @DataSchema
-            interface $typeName
+            interface $typeName { }
 
         """.trimIndent() + "\n" + expectedProperties(typeName, typeName)
 
@@ -85,7 +85,7 @@ class CodeGenerationTests : BaseTest() {
         val typeName = ReplCodeGeneratorImpl.markerInterfacePrefix
         val expectedDeclaration = """
             @DataSchema
-            interface $typeName
+            interface $typeName { }
 
         """.trimIndent() + "\n" + expectedProperties(typeName, typeName)
 
@@ -104,7 +104,7 @@ class CodeGenerationTests : BaseTest() {
         val type2 = ReplCodeGeneratorImpl.markerInterfacePrefix
         val declaration1 = """
             @DataSchema(isOpen = false)
-            interface $type1
+            interface $type1 { }
 
             val $dfName<$type1>.city: $dataCol<$stringName?> @JvmName("${type1}_city") get() = this["city"] as $dataCol<$stringName?>
             val $dfRowName<$type1>.city: $stringName? @JvmName("${type1}_city") get() = this["city"] as $stringName?
@@ -119,7 +119,7 @@ class CodeGenerationTests : BaseTest() {
 
         val declaration2 = """
             @DataSchema
-            interface $type2
+            interface $type2 { }
 
             val $dfName<$type2>.age: $dataCol<$intName> @JvmName("${type2}_age") get() = this["age"] as $dataCol<$intName>
             val $dfRowName<$type2>.age: $intName @JvmName("${type2}_age") get() = this["age"] as $intName
@@ -146,7 +146,7 @@ class CodeGenerationTests : BaseTest() {
         val personClass = (Person::class).qualifiedName!!
         val expected = """
             @DataSchema
-            interface $personClass
+            interface $personClass { }
         """.trimIndent() + "\n" + expectedProperties(personClassName, personShortName)
 
         val code = CodeGenerator.create(useFqNames = false)
@@ -203,7 +203,7 @@ class CodeGenerationTests : BaseTest() {
         val code = codeGen.generate(df.schema(), "Person", false, true, true).code.declarations
         val expected = """
             @DataSchema
-            interface Person
+            interface Person { }
 
         """.trimIndent() + "\n" + expectedProperties("Person", "Person")
         code shouldBe expected

core/generated-sources/src/test/kotlin/org/jetbrains/kotlinx/dataframe/codeGen/ReplCodeGenTests.kt

@@ -75,7 +75,7 @@ class ReplCodeGenTests : BaseTest() {
 
         val expected = """
             @DataSchema
-            interface $marker
+            interface $marker { }
 
             val $dfName<$marker>.age: $dataCol<$intName> @JvmName("${marker}_age") get() = this["age"] as $dataCol<$intName>
             val $dfRowName<$marker>.age: $intName @JvmName("${marker}_age") get() = this["age"] as $intName
@@ -104,7 +104,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker3 = marker + "1"
         val expected3 = """
             @DataSchema
-            interface $marker3 : $markerFull
+            interface $marker3 : $markerFull { }
 
             val $dfName<$marker3>.city: $dataCol<$stringName> @JvmName("${marker3}_city") get() = this["city"] as $dataCol<$stringName>
             val $dfRowName<$marker3>.city: $stringName @JvmName("${marker3}_city") get() = this["city"] as $stringName
@@ -122,7 +122,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker5 = marker + "2"
         val expected5 = """
             @DataSchema
-            interface $marker5 : $markerFull
+            interface $marker5 : $markerFull { }
 
             val $dfName<$marker5>.weight: $dataCol<$intName> @JvmName("${marker5}_weight") get() = this["weight"] as $dataCol<$intName>
             val $dfRowName<$marker5>.weight: $intName @JvmName("${marker5}_weight") get() = this["weight"] as $intName
@@ -145,7 +145,7 @@ class ReplCodeGenTests : BaseTest() {
 
         val expected = """
             @DataSchema
-            interface ${Test2._DataFrameType2::class.simpleName!!} : ${Test2._DataFrameType::class.qualifiedName}, ${Test2._DataFrameType1::class.qualifiedName}
+            interface ${Test2._DataFrameType2::class.simpleName!!} : ${Test2._DataFrameType::class.qualifiedName}, ${Test2._DataFrameType1::class.qualifiedName} { }
 
         """.trimIndent()
 
@@ -164,7 +164,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker = Test2._DataFrameType2::class.simpleName!!
         val expected = """
             @DataSchema
-            interface $marker : ${Test2._DataFrameType::class.qualifiedName}
+            interface $marker : ${Test2._DataFrameType::class.qualifiedName} { }
 
             val $dfName<$marker>.city: $dataCol<$stringName?> @JvmName("${marker}_city") get() = this["city"] as $dataCol<$stringName?>
             val $dfRowName<$marker>.city: $stringName? @JvmName("${marker}_city") get() = this["city"] as $stringName?

core/generated-sources/src/test/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/CodeGenerationTests.kt

@@ -51,4 +51,14 @@ class CodeGenerationTests : DataFrameJupyterTest() {
             row.a
         """.checkCompilation()
     }
+
+    @Test
+    fun `interface without body compiled correctly`() {
+        """
+            val a = dataFrameOf("a")(1, 2, 3)
+            val b = dataFrameOf("b")(1, 2, 3)
+            val ab = dataFrameOf("a", "b")(1, 2)
+            ab.a
+        """.checkCompilation()
+    }
 }

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/codeGen/CodeGeneratorImpl.kt

@@ -226,8 +226,6 @@ internal open class ExtensionsCodeGeneratorImpl(
 
     private fun String.removeQuotes() = this.removeSurrounding("`")
 
-    private fun generateExtensionProperties(markers: List<Marker>) = markers.map { generateExtensionProperties(it) }
-
     private fun generatePropertyCode(
         marker: IsolatedMarker,
         shortMarkerName: String,
@@ -430,11 +428,6 @@ internal class CodeGeneratorImpl(typeRendering: TypeRenderingStrategy = FullyQua
         return CodeGenResult(code, context.generatedMarkers)
     }
 
-    private fun generateInterfaces(
-        schemas: List<Marker>,
-        fields: Boolean,
-    ) = schemas.map { generateInterface(it, fields) }
-
     private fun generateInterface(
         marker: Marker,
         fields: Boolean,
@@ -483,7 +476,7 @@ internal class CodeGeneratorImpl(typeRendering: TypeRenderingStrategy = FullyQua
                 append("\n}")
             }
         } else {
-            ""
+            " { }"
         }
         resultDeclarations.add(header + baseInterfacesDeclaration + body)
         return resultDeclarations.join()

core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/codeGen/CodeGenerationTests.kt

@@ -60,7 +60,7 @@ class CodeGenerationTests : BaseTest() {
         val typeName = ReplCodeGeneratorImpl.markerInterfacePrefix
         val expectedDeclaration = """
             @DataSchema
-            interface $typeName
+            interface $typeName { }
 
         """.trimIndent() + "\n" + expectedProperties(typeName, typeName)
 
@@ -85,7 +85,7 @@ class CodeGenerationTests : BaseTest() {
         val typeName = ReplCodeGeneratorImpl.markerInterfacePrefix
         val expectedDeclaration = """
             @DataSchema
-            interface $typeName
+            interface $typeName { }
 
         """.trimIndent() + "\n" + expectedProperties(typeName, typeName)
 
@@ -104,7 +104,7 @@ class CodeGenerationTests : BaseTest() {
         val type2 = ReplCodeGeneratorImpl.markerInterfacePrefix
         val declaration1 = """
             @DataSchema(isOpen = false)
-            interface $type1
+            interface $type1 { }
 
             val $dfName<$type1>.city: $dataCol<$stringName?> @JvmName("${type1}_city") get() = this["city"] as $dataCol<$stringName?>
             val $dfRowName<$type1>.city: $stringName? @JvmName("${type1}_city") get() = this["city"] as $stringName?
@@ -119,7 +119,7 @@ class CodeGenerationTests : BaseTest() {
 
         val declaration2 = """
             @DataSchema
-            interface $type2
+            interface $type2 { }
 
             val $dfName<$type2>.age: $dataCol<$intName> @JvmName("${type2}_age") get() = this["age"] as $dataCol<$intName>
             val $dfRowName<$type2>.age: $intName @JvmName("${type2}_age") get() = this["age"] as $intName
@@ -146,7 +146,7 @@ class CodeGenerationTests : BaseTest() {
         val personClass = (Person::class).qualifiedName!!
         val expected = """
             @DataSchema
-            interface $personClass
+            interface $personClass { }
         """.trimIndent() + "\n" + expectedProperties(personClassName, personShortName)
 
         val code = CodeGenerator.create(useFqNames = false)
@@ -203,7 +203,7 @@ class CodeGenerationTests : BaseTest() {
         val code = codeGen.generate(df.schema(), "Person", false, true, true).code.declarations
         val expected = """
             @DataSchema
-            interface Person
+            interface Person { }
 
         """.trimIndent() + "\n" + expectedProperties("Person", "Person")
         code shouldBe expected

core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/codeGen/ReplCodeGenTests.kt

@@ -75,7 +75,7 @@ class ReplCodeGenTests : BaseTest() {
 
         val expected = """
             @DataSchema
-            interface $marker
+            interface $marker { }
 
             val $dfName<$marker>.age: $dataCol<$intName> @JvmName("${marker}_age") get() = this["age"] as $dataCol<$intName>
             val $dfRowName<$marker>.age: $intName @JvmName("${marker}_age") get() = this["age"] as $intName
@@ -104,7 +104,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker3 = marker + "1"
         val expected3 = """
             @DataSchema
-            interface $marker3 : $markerFull
+            interface $marker3 : $markerFull { }
 
             val $dfName<$marker3>.city: $dataCol<$stringName> @JvmName("${marker3}_city") get() = this["city"] as $dataCol<$stringName>
             val $dfRowName<$marker3>.city: $stringName @JvmName("${marker3}_city") get() = this["city"] as $stringName
@@ -122,7 +122,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker5 = marker + "2"
         val expected5 = """
             @DataSchema
-            interface $marker5 : $markerFull
+            interface $marker5 : $markerFull { }
 
             val $dfName<$marker5>.weight: $dataCol<$intName> @JvmName("${marker5}_weight") get() = this["weight"] as $dataCol<$intName>
             val $dfRowName<$marker5>.weight: $intName @JvmName("${marker5}_weight") get() = this["weight"] as $intName
@@ -145,7 +145,7 @@ class ReplCodeGenTests : BaseTest() {
 
         val expected = """
             @DataSchema
-            interface ${Test2._DataFrameType2::class.simpleName!!} : ${Test2._DataFrameType::class.qualifiedName}, ${Test2._DataFrameType1::class.qualifiedName}
+            interface ${Test2._DataFrameType2::class.simpleName!!} : ${Test2._DataFrameType::class.qualifiedName}, ${Test2._DataFrameType1::class.qualifiedName} { }
 
         """.trimIndent()
 
@@ -164,7 +164,7 @@ class ReplCodeGenTests : BaseTest() {
         val marker = Test2._DataFrameType2::class.simpleName!!
         val expected = """
             @DataSchema
-            interface $marker : ${Test2._DataFrameType::class.qualifiedName}
+            interface $marker : ${Test2._DataFrameType::class.qualifiedName} { }
 
             val $dfName<$marker>.city: $dataCol<$stringName?> @JvmName("${marker}_city") get() = this["city"] as $dataCol<$stringName?>
             val $dfRowName<$marker>.city: $stringName? @JvmName("${marker}_city") get() = this["city"] as $stringName?

core/src/test/kotlin/org/jetbrains/kotlinx/dataframe/jupyter/CodeGenerationTests.kt

@@ -51,4 +51,14 @@ class CodeGenerationTests : DataFrameJupyterTest() {
             row.a
         """.checkCompilation()
     }
+
+    @Test
+    fun `interface without body compiled correctly`() {
+        """
+            val a = dataFrameOf("a")(1, 2, 3)
+            val b = dataFrameOf("b")(1, 2, 3)
+            val ab = dataFrameOf("a", "b")(1, 2)
+            ab.a
+        """.checkCompilation()
+    }
 }