Add serialization to binary format of empty WASM module

5 files changed, 95 insertions, 17 deletions

diff --git a/src/test/java/org/shedlang/compiler/backends/ExampleTests.java b/src/test/java/org/shedlang/compiler/backends/ExampleTests.java
index df0aae24..c5f584d8 100644
--- a/src/test/java/org/shedlang/compiler/backends/ExampleTests.java
+++ b/src/test/java/org/shedlang/compiler/backends/ExampleTests.java
@@ -6,13 +6,12 @@ import org.shedlang.compiler.ShedCompiler;
 import org.shedlang.compiler.backends.llvm.ExecutionResult;
 import org.shedlang.compiler.config.ProjectConfig;
 import org.shedlang.compiler.filesystem.ShedCompilerFiles;
+import org.shedlang.compiler.testing.ProcessRunner;
 import org.shedlang.compiler.util.P;
 
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Optional;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -50,21 +49,7 @@ public abstract class ExampleTests {
             .orElse(P.vector())
             .plus(executableName(binary));
 
-        var process = new ProcessBuilder()
-            .command(fullCommand)
-            .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());
-            var stderr = stderrReader.lines().collect(Collectors.joining());
-
-            return new ExecutionResult(exitCode, stdout, stderr);
-        }
+        return ProcessRunner.run(fullCommand);
     }
 
     protected abstract Backend backend();
diff --git a/src/test/java/org/shedlang/compiler/backends/llvm/ExecutionResult.java b/src/test/java/org/shedlang/compiler/backends/llvm/ExecutionResult.java
index 1136e243..d977d70d 100644
--- a/src/test/java/org/shedlang/compiler/backends/llvm/ExecutionResult.java
+++ b/src/test/java/org/shedlang/compiler/backends/llvm/ExecutionResult.java
@@ -1,4 +1,11 @@
 package org.shedlang.compiler.backends.llvm;
 
 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/shedlang/compiler/backends/wasm/structure/WasmBinaryFormatModuleTests.java b/src/test/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormatModuleTests.java
new file mode 100644
index 00000000..5ddad366
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/backends/wasm/structure/WasmBinaryFormatModuleTests.java
@@ -0,0 +1,52 @@
+package org.shedlang.compiler.backends.wasm.structure;
+
+import au.com.origin.snapshots.Expect;
+import au.com.origin.snapshots.junit5.SnapshotExtension;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.shedlang.compiler.backends.wasm.structure.ast.WasmModule;
+import org.shedlang.compiler.testing.ProcessRunner;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+@ExtendWith({SnapshotExtension.class})
+public class WasmBinaryFormatModuleTests {
+    private Expect expect;
+
+    @Test
+    public void canSerializeEmptyModule() throws IOException, InterruptedException {
+        var module = WasmModule.builder()
+            .build();
+
+        var result = serializeModule(module);
+
+        expect.toMatchSnapshot(result);
+    }
+
+    private String serializeModule(WasmModule module) throws IOException, InterruptedException {
+        Files.createDirectories(Path.of("tests-tmp"));
+        var temporaryDirectory = Files.createTempDirectory(Path.of("tests-tmp"), "WasmBinaryFormat");
+        var modulePath = temporaryDirectory.resolve("module.wasm");
+
+        try (var outputStream = new FileOutputStream(modulePath.toFile())) {
+            WasmBinaryFormat.serializeModule(module, outputStream);
+        }
+
+        validate(modulePath);
+
+        return objdump(modulePath);
+    }
+
+    private void validate(Path path) throws IOException, InterruptedException {
+        ProcessRunner.run(List.of("wasm-validate", "--enable-exceptions", path.toString()))
+            .throwOnError();
+    }
+
+    private String objdump(Path path) throws IOException, InterruptedException {
+        return ProcessRunner.run(List.of("wasm-objdump", "-dx", path.toString())).throwOnError().stdout();
+    }
+}
diff --git a/src/test/java/org/shedlang/compiler/backends/wasm/structure/snapshots/WasmBinaryFormatModuleTests.snap b/src/test/java/org/shedlang/compiler/backends/wasm/structure/snapshots/WasmBinaryFormatModuleTests.snap
new file mode 100644
index 00000000..370ab0d6
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/backends/wasm/structure/snapshots/WasmBinaryFormatModuleTests.snap
@@ -0,0 +1,3 @@
+org.shedlang.compiler.backends.wasm.structure.WasmBinaryFormatModuleTests.canSerializeEmptyModule=[
+module.wasm:	file format wasm 0x1Section Details:Code Disassembly:
+]
\ No newline at end of file
diff --git a/src/test/java/org/shedlang/compiler/testing/ProcessRunner.java b/src/test/java/org/shedlang/compiler/testing/ProcessRunner.java
new file mode 100644
index 00000000..c1bfd481
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/testing/ProcessRunner.java
@@ -0,0 +1,31 @@
+package org.shedlang.compiler.testing;
+
+import org.shedlang.compiler.backends.llvm.ExecutionResult;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ProcessRunner {
+    private ProcessRunner() {
+    }
+
+    public static ExecutionResult run(List<String> command) throws IOException, InterruptedException {
+        var process = new ProcessBuilder()
+            .command(command)
+            .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());
+            var stderr = stderrReader.lines().collect(Collectors.joining());
+
+            return new ExecutionResult(exitCode, stdout, stderr);
+        }
+    }
+}