Merge pull request #3 from metaobjectsdev/feat/fr019-cross-port

test(codegen-spring): pin TPH enum-@Discriminator as enum-typed

Author: dmealing

server/java/codegen-spring/src/test/java/com/metaobjects/generator/spring/TphDiscriminatorEnumConformanceTest.java

@@ -0,0 +1,65 @@
+package com.metaobjects.generator.spring;
+
+import com.metaobjects.loader.MetaDataLoader;
+import com.metaobjects.registry.SharedRegistryTestBase;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * FR-017 / typed-enum coherence guard: a TPH {@code @discriminator} that is declared
+ * {@code field.enum} MUST be typed in the generated DTO as the value-constrained enum (the
+ * cross-port typed-enum contract — TS string-literal union, Python {@code Literal}, C#/Kotlin/Java
+ * enum), NEVER as a raw {@code String}.
+ *
+ * <p>This is otherwise only exercised end-to-end by the docker-gated api-contract TPH corpus, where
+ * a regression to a {@code String}-typed discriminator would slip past the HTTP/JSON-seeding ports
+ * (it deserializes fine) and only break the direct-constructing Java lane. This fast unit-level
+ * assertion pins the static type so the discriminator can't silently regress to {@code String}.
+ * Loads the SAME shared fixture the integration lane uses
+ * ({@code fixtures/api-contract-conformance/tph/meta.json}: TPH base {@code Auth} with a
+ * {@code field.enum type} discriminator over {@code Bridge|Copay|PriorAuth}).</p>
+ */
+public class TphDiscriminatorEnumConformanceTest extends SharedRegistryTestBase {
+
+    @Rule
+    public TemporaryFolder tmp = new TemporaryFolder();
+
+    @Test
+    public void tphEnumDiscriminatorIsTypedAsTheEnumNotString() throws Exception {
+        Path repoRoot = Path.of(System.getProperty("user.dir")).resolve("../../..").normalize();
+        Path fixture = repoRoot.resolve("fixtures/api-contract-conformance/tph/meta.json");
+        assertTrue("shared TPH fixture must exist at " + fixture, Files.exists(fixture));
+        MetaDataLoader loader = SpringTestFixtures.loadFixture(
+            tmp.newFolder().toPath(), "tphDiscriminatorEnum", Files.readString(fixture));
+
+        Path out = tmp.newFolder().toPath();
+        Map<String, String> args = new HashMap<>();
+        args.put("outputDir", out.toString());
+        SpringDtoGenerator gen = new SpringDtoGenerator();
+        gen.setArgs(args);
+        gen.execute(loader);
+
+        // The TPH base's union DTO carries the discriminator.
+        Path dto = out.resolve("acme/auth/AuthDto.java");
+        assertTrue("AuthDto.java must be emitted", Files.exists(dto));
+        String src = Files.readString(dto);
+
+        // The discriminator component is the value-constrained enum, not a bare String.
+        assertTrue("the @discriminator field.enum must be typed as the generated enum; saw:\n" + src,
+            src.contains("AuthType type"));
+        assertTrue("the discriminator enum must be materialized with its @values; saw:\n" + src,
+            src.contains("public enum AuthType { Bridge, Copay, PriorAuth }"));
+        assertFalse("the @discriminator must NOT regress to a raw String component; saw:\n" + src,
+            src.contains("String type"));
+    }
+}