3 files changed, 64 insertions, 1 deletions
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);
+        }
+    }
+}