Fix generic tagged unions with non-generic constituents (#428)

Author: vojtechhabarta

typescript-generator-core/src/main/java/cz/habarta/typescript/generator/compiler/ModelCompiler.java

@@ -902,7 +902,7 @@ private TsModel createAndUseTaggedUnions(final SymbolTable symbolTable, TsModel
                 final List<TsType> unionTypes = new ArrayList<>();
                 for (Class<?> cls : bean.getTaggedUnionClasses()) {
                     final TsType type;
-                    if (isGeneric) {
+                    if (isGeneric && cls.getTypeParameters().length != 0) {
                         final List<String> mappedGenericVariables = GenericsResolver.mapGenericVariablesToBase(cls, bean.getOrigin());
                         type = new TsType.GenericReferenceType(
                                 symbolTable.getSymbol(cls),

typescript-generator-core/src/test/java/cz/habarta/typescript/generator/TaggedUnionsTest.java

@@ -460,4 +460,36 @@ public void testBaseWithGenerics() {
         Assert.assertTrue(output.contains("type BaseUnion<A, B> = FlippedGenericParameters<B, A>"));
     }
 
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY)
+    @JsonSubTypes({
+        @JsonSubTypes.Type(value = Foo.class, name = "Foo"),
+        @JsonSubTypes.Type(value = Bar.class, name = "Bar")
+    })
+    public static abstract class Entity<T> {
+        public T id;
+    }
+
+    public static class Foo extends Entity<String> {
+    }
+
+    public static class Bar extends Entity<Integer> {
+    }
+
+    public class EntityCollection {
+        public List<Entity<?>> entities;
+    }
+
+    @Test
+    public void testGenericBaseWithNonGenericSubType() {
+        final Settings settings = TestUtils.settings();
+        settings.outputFileType = TypeScriptFileType.implementationFile;
+        settings.outputKind = TypeScriptOutputKind.module;
+        settings.mapClasses = ClassMapping.asClasses;
+        settings.mapEnum = EnumMapping.asEnum;
+        settings.nonConstEnums = true;
+        settings.mapPackagesToNamespaces = true;
+        final String output = new TypeScriptGenerator(settings).generateTypeScript(Input.from(EntityCollection.class));
+        Assert.assertTrue(output.contains("type EntityUnion<T> = cz.habarta.typescript.generator.TaggedUnionsTest.Foo | cz.habarta.typescript.generator.TaggedUnionsTest.Bar"));
+    }
+
 }