From 8d3923b4371580b48c3c6668c828a7dd63e61255 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Sun, 26 Apr 2026 17:24:24 +0100
Subject: Add stubbed java output example

---
 examples/01-struct/output/java/.gitignore          |  2 +
 examples/01-struct/output/java/pom.xml             | 39 +++++++++++++++++++
 .../src/main/java/org/zwobble/example/Main.java    |  7 ++++
 .../zwobble/hobgoblin/compiler/ExampleTests.java   |  9 ++++-
 .../compiler/testing/ExecutionResult.java          | 11 ++++++
 .../compiler/testing/TestProcessRunner.java        | 45 ++++++++++++++++++++++
 6 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 examples/01-struct/output/java/.gitignore
 create mode 100644 examples/01-struct/output/java/pom.xml
 create mode 100644 examples/01-struct/output/java/src/main/java/org/zwobble/example/Main.java
 create mode 100644 src/test/java/org/zwobble/hobgoblin/compiler/testing/ExecutionResult.java
 create mode 100644 src/test/java/org/zwobble/hobgoblin/compiler/testing/TestProcessRunner.java

diff --git a/examples/01-struct/output/java/.gitignore b/examples/01-struct/output/java/.gitignore
new file mode 100644
index 0000000..ff511d4
--- /dev/null
+++ b/examples/01-struct/output/java/.gitignore
@@ -0,0 +1,2 @@
+/src/gen/
+/target/
diff --git a/examples/01-struct/output/java/pom.xml b/examples/01-struct/output/java/pom.xml
new file mode 100644
index 0000000..7493667
--- /dev/null
+++ b/examples/01-struct/output/java/pom.xml
@@ -0,0 +1,39 @@
+<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>org.zwobble.hobgoblin.examples</groupId>
+  <artifactId>example</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>25</maven.compiler.source>
+    <maven.compiler.target>25</maven.compiler.target>
+  </properties>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>build-helper-maven-plugin</artifactId>
+        <version>3.6.1</version>
+        <executions>
+          <execution>
+            <id>add-source</id>
+            <phase>generate-sources</phase>
+            <goals>
+              <goal>add-source</goal>
+            </goals>
+            <configuration>
+              <sources>
+                <source>src/gen/java</source>
+              </sources>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
diff --git a/examples/01-struct/output/java/src/main/java/org/zwobble/example/Main.java b/examples/01-struct/output/java/src/main/java/org/zwobble/example/Main.java
new file mode 100644
index 0000000..5e0e111
--- /dev/null
+++ b/examples/01-struct/output/java/src/main/java/org/zwobble/example/Main.java
@@ -0,0 +1,7 @@
+package org.zwobble.example;
+
+public class Main {
+    public static void main() {
+
+    }
+}
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/ExampleTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/ExampleTests.java
index e892cd9..8e68c09 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/ExampleTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/ExampleTests.java
@@ -2,6 +2,7 @@ package org.zwobble.hobgoblin.compiler;
 
 import org.junit.jupiter.api.DynamicTest;
 import org.junit.jupiter.api.TestFactory;
+import org.zwobble.hobgoblin.compiler.testing.TestProcessRunner;
 
 import java.io.IOException;
 import java.util.List;
@@ -17,7 +18,13 @@ public class ExampleTests {
             ));
     }
 
-    private void runTest(ExampleSet exampleSet) throws IOException {
+    private void runTest(ExampleSet exampleSet) throws IOException, InterruptedException {
         HobgoblinCompiler.compile(exampleSet.path(), List.of());
+
+        var javaProjectPath = exampleSet.path().resolve("output/java");
+        TestProcessRunner.command(List.of("mvn", "compile"))
+            .cwd(javaProjectPath)
+            .runCaptureOutput()
+            .throwOnError();
     }
 }
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/testing/ExecutionResult.java b/src/test/java/org/zwobble/hobgoblin/compiler/testing/ExecutionResult.java
new file mode 100644
index 0000000..553e41b
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/testing/ExecutionResult.java
@@ -0,0 +1,11 @@
+package org.zwobble.hobgoblin.compiler.testing;
+
+public record ExecutionResult(int exitCode, String stdout, String stderr) {
+    public ExecutionResult throwOnError() {
+        if (exitCode == 0) {
+            return this;
+        } else {
+            throw new AssertionError("exit code was " + exitCode + "\nstdout:\n" + stdout + "\nstderr:\n" + stderr);
+        }
+    }
+}
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/testing/TestProcessRunner.java b/src/test/java/org/zwobble/hobgoblin/compiler/testing/TestProcessRunner.java
new file mode 100644
index 0000000..f4074f8
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/testing/TestProcessRunner.java
@@ -0,0 +1,45 @@
+package org.zwobble.hobgoblin.compiler.testing;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class TestProcessRunner {
+    public static TestProcessRunner command(List<String> command) {
+        return new TestProcessRunner(
+            new ProcessBuilder().command(command)
+        );
+    }
+
+    private final ProcessBuilder processBuilder;
+
+    private TestProcessRunner(ProcessBuilder processBuilder) {
+        this.processBuilder = processBuilder;
+    }
+
+    public TestProcessRunner cwd(Path cwd) {
+        this.processBuilder.directory(cwd.toFile());
+        return this;
+    }
+
+    /**
+     * Run a process until it exits, capturing its stdout and stderr.
+     */
+    public ExecutionResult runCaptureOutput() throws IOException, InterruptedException {
+        var process = this.processBuilder.start();
+
+        var exitCode = process.waitFor();
+
+        try (
+            var stdoutReader = process.inputReader(StandardCharsets.UTF_8);
+            var stderrReader = process.errorReader(StandardCharsets.UTF_8)
+        ) {
+            var stdout = stdoutReader.lines().collect(Collectors.joining("\n"));
+            var stderr = stderrReader.lines().collect(Collectors.joining("\n"));
+
+            return new ExecutionResult(exitCode, stdout, stderr);
+        }
+    }
+}
-- 
cgit v1.2.3