Emit type inheritance statements for concrete document types

This relates to issue #26126 where inheritance specified in the
schema was not propagated to the generated meta type, causing `is-a`
type checks to not give the expected results.

2 files changed, 50 insertions, 7 deletions

diff --git a/documentgen-test/src/test/java/com/yahoo/vespa/config/DocumentGenPluginTest.java b/documentgen-test/src/test/java/com/yahoo/vespa/config/DocumentGenPluginTest.java
index 680853ef687..bd2b057835c 100644
--- a/documentgen-test/src/test/java/com/yahoo/vespa/config/DocumentGenPluginTest.java
+++ b/documentgen-test/src/test/java/com/yahoo/vespa/config/DocumentGenPluginTest.java
@@ -47,8 +47,10 @@ import com.yahoo.vespa.documentgen.test.Book;
 import com.yahoo.vespa.documentgen.test.Book.Ss0;
 import com.yahoo.vespa.documentgen.test.Book.Ss1;
 import com.yahoo.vespa.documentgen.test.Common;
+import com.yahoo.vespa.documentgen.test.Common2;
 import com.yahoo.vespa.documentgen.test.ConcreteDocumentFactory;
 import com.yahoo.vespa.documentgen.test.Music;
+import com.yahoo.vespa.documentgen.test.Music2;
 import com.yahoo.vespa.documentgen.test.Music3;
 import com.yahoo.vespa.documentgen.test.Music4;
 import com.yahoo.vespa.documentgen.test.Parent;
@@ -1024,5 +1026,36 @@ public class DocumentGenPluginTest {
         assertTrue(docType.hasImportedField("my_foo"));
         assertFalse(docType.hasImportedField("some_field_that_does_not_exist"));
     }
+
+    @Test
+    public void subtypes_are_tagged_as_inheriting_supertypes() {
+        // music -> common
+        assertTrue(Music.type.isA("common"));
+        assertTrue(Music.type.inherits(Common.type));
+        // ... but not common2
+        assertFalse(Music.type.inherits(Common2.type));
+
+        // music3 -> (music2 -> common), common2
+        assertTrue(Music3.type.isA("common"));
+        assertTrue(Music3.type.isA("common2"));
+        assertTrue(Music3.type.isA("music2"));
+        assertTrue(Music3.type.inherits(Common.type));
+        assertTrue(Music3.type.inherits(Common2.type));
+        assertTrue(Music3.type.inherits(Music2.type));
+        // ... but not parent
+        assertFalse(Music3.type.isA("parent"));
+        assertFalse(Music3.type.inherits(Parent.type));
+
+        // music4 -> music3 -> (music2 -> common), common2
+        assertTrue(Music4.type.inherits(Common.type));
+        assertTrue(Music4.type.inherits(Common2.type));
+        assertTrue(Music4.type.inherits(Music2.type));
+        assertTrue(Music4.type.inherits(Music3.type));
+        // ... but not music
+        assertFalse(Music4.type.inherits(Music.type));
+
+        // parent has no explicit inheritance
+        assertFalse(Parent.type.isA("common"));
+    }
     
 }
diff --git a/vespa-documentgen-plugin/src/main/java/com/yahoo/vespa/DocumentGenMojo.java b/vespa-documentgen-plugin/src/main/java/com/yahoo/vespa/DocumentGenMojo.java
index 0f3531720ae..d753f3d9e73 100644
--- a/vespa-documentgen-plugin/src/main/java/com/yahoo/vespa/DocumentGenMojo.java
+++ b/vespa-documentgen-plugin/src/main/java/com/yahoo/vespa/DocumentGenMojo.java
@@ -448,7 +448,7 @@ public class DocumentGenMojo extends AbstractMojo {
         out.write(ind(1)+"@Override protected boolean isGenerated() { return true; }\n\n");
 
         Collection<Field> allUniqueFields = getAllUniqueFields(multiExtends, docType.getAllFields());
-        exportExtendedStructTypeGetter(className, docType.getName(), allUniqueFields, docType.getFieldSets(),
+        exportExtendedStructTypeGetter(className, docType.getName(), docType.getInherited(), allUniqueFields, docType.getFieldSets(),
                 docType.getImportedFieldNames(), out, 1, "getDocumentType", "com.yahoo.document.DocumentType");
         exportCopyConstructor(className, out, 1, true);
 
@@ -612,14 +612,17 @@ public class DocumentGenMojo extends AbstractMojo {
             out.write(ind(ind) + "importedFieldNames.add(\"" + importedField + "\");\n");
         }
     }
-    private static void exportExtendedStructTypeGetter(String className, String name, Collection<Field> fields, Set<FieldSet> fieldSets,
-                                                       Set<String> importedFieldNames, Writer out, int ind, String methodName, String retType) throws IOException {
+    private static void exportExtendedStructTypeGetter(String className, String name, Collection<NewDocumentType> parentTypes,
+                                                       Collection<Field> fields, Set<FieldSet> fieldSets,
+                                                       Set<String> importedFieldNames, Writer out, int ind,
+                                                       String methodName, String retType) throws IOException {
         out.write(ind(ind)+"private static "+retType+" "+methodName+"() {\n");
+        String bodyIndent = ind(ind + 1);
         if (importedFieldNames != null) {
             exportImportedFields(importedFieldNames, out, ind + 1);
-            out.write(ind(ind+1)+retType+" ret = new "+retType+"(\"" + name + "\", importedFieldNames);\n");
+            out.write(bodyIndent+retType+" ret = new "+retType+"(\"" + name + "\", importedFieldNames);\n");
         } else {
-            out.write(ind(ind+1)+retType+" ret = new "+retType+"(\""+name+"\");\n");
+            out.write(bodyIndent+retType+" ret = new "+retType+"(\""+name+"\");\n");
         }
         for (Field f : fields) {
             if (f.getDataType().equals(DataType.STRING)) {
@@ -631,8 +634,13 @@ public class DocumentGenMojo extends AbstractMojo {
         if (fieldSets != null) {
             exportFieldSetDefinition(fieldSets, out, ind+1);
         }
+        for (NewDocumentType parentType : parentTypes) {
+            if (!parentType.getName().equals("document")) {
+                out.write("%sret.inherit(%s.type);\n".formatted(bodyIndent, className(parentType.getName())));
+            }
+        }
 
-        out.write(ind(ind+1)+"return ret;\n");
+        out.write(bodyIndent+"return ret;\n");
         out.write(ind(ind)+"}\n\n");
     }
 
@@ -762,7 +770,9 @@ public class DocumentGenMojo extends AbstractMojo {
                 ind(ind+2)+"super("+structClassName+".type);\n" +
                 ind(ind+1)+"}\n\n");
                 exportCopyConstructor(structClassName, out, ind+1, false);
-                exportExtendedStructTypeGetter(structClassName, structType.getName(), structType.getFields(), null, null, out, ind+1, "getStructType", "com.yahoo.document.StructDataType");
+                exportExtendedStructTypeGetter(structClassName, structType.getName(), List.of(),
+                        structType.getFields(), null, null, out, ind+1, "getStructType",
+                        "com.yahoo.document.StructDataType");
                 exportAssign(structType, structClassName, out, ind+1);
                 exportFieldsAndAccessors(structClassName, structType.getFields(), out, ind+1, true);