Define Automatic-Module-Name via maven-jar-plugin

.claude/CLAUDE.md

@@ -79,8 +79,7 @@ public `Generator`/`TestCase`/`Generators`/`Hegel` surface stays in `dev.hegel`.
 
 ## Coverage notes
 
-Two genuinely-unreachable defensive catch blocks are excluded via `@Generated` (JaCoCo ignores
-`*Generated*`-named annotations): the `NoSuchAlgorithmException` for SHA-256 and the reflective
-dispatch in `HegelTestExtension`. Everything else is covered by real-engine integration tests plus
+One genuinely-unreachable defensive catch block is excluded via `@Generated` (JaCoCo ignores
+`*Generated*`-named annotations): the `NoSuchAlgorithmException` for SHA-256. Everything else is covered by real-engine integration tests plus
 `FakeLibhegel`-driven error-path tests. The engine's `collection_more`/`new_collection` out-params
 are read unconditionally (the engine signals exhaustion on the following draw, not at those calls).

.gitignore

@@ -2,3 +2,11 @@ target/
 .hegel/
 *.class
 *.pyc
+CLAUDE.local.md
+.claude/settings.local.json
+
+# whitelist .claude files, rather than blacklist. Some local claude files
+# (skills, agents) have to live in .claude - as opposed to eg CLAUDE.local.md,
+# which we gitignore at the top level.
+.claude/*
+!.claude/CLAUDE.md

RELEASE.md

@@ -0,0 +1,8 @@
+RELEASE_TYPE: minor
+
+Improve Java Platform Module System support:
+
+- Define `Automatic-Module-Name: dev.hegel` in the jar manifest, giving the artifact a stable
+  module name on the module path.
+- `@HegelTest` now invokes the test method through the JUnit platform's reflection support, so
+  modular consumers no longer have to open their test package to `dev.hegel`.

pom.xml

@@ -99,6 +99,19 @@
         <version>3.13.0</version>
       </plugin>
 
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
+        <version>3.4.2</version>
+        <configuration>
+          <archive>
+            <manifestEntries>
+              <Automatic-Module-Name>dev.hegel</Automatic-Module-Name>
+            </manifestEntries>
+          </archive>
+        </configuration>
+      </plugin>
+
       <!-- Filter src/main/java-templates into generated-sources, substituting ${libhegel.version}
            into BuildInfo.ENGINE_VERSION. build-helper (below) adds the output to the compile path. -->
       <plugin>
@@ -184,6 +197,26 @@
         </configuration>
       </plugin>
 
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-invoker-plugin</artifactId>
+        <version>3.9.0</version>
+        <configuration>
+          <projectsDirectory>src/it</projectsDirectory>
+          <cloneProjectsTo>${project.build.directory}/it</cloneProjectsTo>
+          <streamLogs>true</streamLogs>
+        </configuration>
+        <executions>
+          <execution>
+            <id>module-consumer-it</id>
+            <goals>
+              <goal>install</goal>
+              <goal>run</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+
       <plugin>
         <groupId>com.diffplug.spotless</groupId>
         <artifactId>spotless-maven-plugin</artifactId>

src/it/module-consumer/invoker.properties

@@ -0,0 +1,3 @@
+# `test` compiles the module (resolving `requires dev.hegel;`, the module-name guard) and runs
+# the @HegelTest against the real engine, consuming hegel on the module path end to end.
+invoker.goals = test

src/it/module-consumer/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>dev.hegel.it</groupId>
+  <artifactId>module-consumer</artifactId>
+  <version>1.0</version>
+  <packaging>jar</packaging>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.release>22</maven.compiler.release>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>dev.hegel</groupId>
+      <artifactId>hegel</artifactId>
+      <!-- Filtered by the invoker plugin to the version under test. -->
+      <version>@project.version@</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>5.11.4</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.13.0</version>
+      </plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.5.2</version>
+        <configuration>
+          <argLine>--enable-native-access=dev.hegel</argLine>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/it/module-consumer/src/main/java/module-info.java

@@ -0,0 +1,6 @@
+// The presence of `module-info.java` puts hegel on the module path. `requires dev.hegel;`
+// names the automatic module by its committed `Automatic-Module-Name`; if that name ever
+// changes, this no longer resolves and the build fails — which is the regression we guard.
+module dev.hegel.consumer {
+    requires dev.hegel;
+}

src/it/module-consumer/src/test/java/dev/hegel/consumer/ConsumerTest.java

@@ -0,0 +1,16 @@
+package dev.hegel.consumer;
+
+import static dev.hegel.Generators.integers;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import dev.hegel.HegelTest;
+import dev.hegel.TestCase;
+
+class ConsumerTest {
+    @HegelTest
+    void additionCommutes(TestCase tc) {
+        int x = tc.draw(integers().min(0).max(100));
+        int y = tc.draw(integers().min(0).max(100));
+        assertEquals(x + y, y + x);
+    }
+}

src/main/java/dev/hegel/HegelTestExtension.java

@@ -1,6 +1,5 @@
 package dev.hegel;
 
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.EnumSet;
@@ -14,6 +13,7 @@
 import org.junit.jupiter.api.extension.ReflectiveInvocationContext;
 import org.junit.jupiter.api.extension.TestTemplateInvocationContext;
 import org.junit.jupiter.api.extension.TestTemplateInvocationContextProvider;
+import org.junit.platform.commons.support.ReflectionSupport;
 
 /**
  * JUnit 5 extension backing {@link HegelTest}. Reports the property as a single test entry and
@@ -76,7 +76,7 @@ public void interceptTestTemplateMethod(
             HegelTest ann = method.getAnnotation(HegelTest.class);
             Settings settings = settingsFrom(ann, method.getName());
             Object target = invocationContext.getTarget().orElse(null);
-            Hegel.test(tc -> invoke(method, target, tc), settings);
+            Hegel.test(tc -> ReflectionSupport.invokeMethod(method, target, tc), settings);
         }
     }
 
@@ -120,21 +120,4 @@ static boolean isDefaultPhases(Phase[] phases) {
     static boolean isTestCaseParam(Class<?> type) {
         return type == TestCase.class;
     }
-
-    @Generated // thin reflective dispatch; failure propagation is verified end-to-end.
-    private static void invoke(Method method, Object target, TestCase tc) {
-        try {
-            method.setAccessible(true);
-            method.invoke(target, tc);
-        } catch (InvocationTargetException e) {
-            sneakyThrow(e.getCause());
-        } catch (IllegalAccessException e) {
-            throw new HegelException("Cannot invoke @HegelTest method " + method.getName(), e);
-        }
-    }
-
-    @SuppressWarnings("unchecked")
-    private static <E extends Throwable> void sneakyThrow(Throwable t) throws E {
-        throw (E) t;
-    }
 }