Merge pull request #1202 from quickfix-j/copilot/ensure-message-code-generator-consistency

Add golden-file regression tests for FIX42, FIX44, FixLatest code generation

Author: chrjohn

quickfixj-codegenerator/src/main/java/org/quickfixj/codegenerator/MessageCodeGenerator.java

@@ -81,7 +81,7 @@ protected void logInfo(String msg) {
     }
 
     protected void logDebug(String msg) {
-        System.out.println(msg);
+        // no-op by default; override (e.g. MavenMessageCodeGenerator) to enable debug output
     }
 
     protected void logError(String msg, Throwable e) {

quickfixj-codegenerator/src/test/java/org/quickfixj/codegenerator/GoldenFileTest.java

@@ -0,0 +1,179 @@
+package org.quickfixj.codegenerator;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+/**
+ * Golden-file regression test for the code generator.
+ *
+ * <p>The test runs {@link MessageCodeGenerator} against the real FIX42 and FIX44 dictionaries
+ * and compares every generated {@code .java} file byte-for-byte against the committed golden
+ * files stored in {@code src/test/resources/golden/fix42} and
+ * {@code src/test/resources/golden/fix44}.
+ *
+ * <p>FIX42 is used because it contains repeating groups (38 of them), while still being
+ * smaller than FIX44. FIX44 is used because it contains 233 groups, including nested ones
+ * (relevant to issue #1084).
+ *
+ * <p>If the generator output must intentionally change, regenerate the golden files by running
+ * the {@code GenerateGoldenFiles} utility in the {@code src/test/java} tree and committing the
+ * updated golden files together with the generator changes.
+ */
+public class GoldenFileTest {
+
+    @Rule
+    public TemporaryFolder tempFolder = new TemporaryFolder();
+
+    private File schemaDirectory = new File("./src/main/resources/org/quickfixj/codegenerator");
+    private File goldenBase = new File("./src/test/resources/golden");
+
+    private File fix42DictFile = new File(
+            "../quickfixj-messages/quickfixj-messages-fix42/src/main/resources/FIX42.xml");
+    private File fix44DictFile = new File(
+            "../quickfixj-messages/quickfixj-messages-fix44/src/main/resources/FIX44.xml");
+
+    private MessageCodeGenerator generator;
+
+    @Before
+    public void setup() {
+        generator = new MessageCodeGenerator();
+    }
+
+    // -------------------------------------------------------------------------
+    // FIX42 – has fields, messages, and repeating groups (no components)
+    // -------------------------------------------------------------------------
+
+    @Test
+    public void testFix42GenerationMatchesGolden() throws Exception {
+        File outputDir = tempFolder.newFolder("fix42");
+        generateCode(fix42DictFile, "FIX42", "quickfix.fix42", outputDir);
+        assertMatchesGolden(new File(goldenBase, "fix42"), outputDir, "FIX42");
+    }
+
+    // -------------------------------------------------------------------------
+    // FIX44 – has fields, messages, components, and 233 groups (incl. nested)
+    // -------------------------------------------------------------------------
+
+    @Test
+    public void testFix44GenerationMatchesGolden() throws Exception {
+        File outputDir = tempFolder.newFolder("fix44");
+        generateCode(fix44DictFile, "FIX44", "quickfix.fix44", outputDir);
+        assertMatchesGolden(new File(goldenBase, "fix44"), outputDir, "FIX44");
+    }
+
+    // -------------------------------------------------------------------------
+    // Helpers
+    // -------------------------------------------------------------------------
+
+    private void generateCode(File dictFile, String name, String messagePackage, File outputDir)
+            throws Exception {
+        MessageCodeGenerator.Task task = new MessageCodeGenerator.Task();
+        task.setName(name);
+        task.setSpecification(dictFile);
+        task.setTransformDirectory(schemaDirectory);
+        task.setMessagePackage(messagePackage);
+        task.setOutputBaseDirectory(outputDir);
+        task.setFieldPackage("quickfix.field");
+        task.setOverwrite(true);
+        task.setOrderedFields(true);
+        task.setDecimalGenerated(true);
+        generator.generate(task);
+    }
+
+    /**
+     * Recursively walks the golden directory and verifies that each {@code .java} file has an
+     * identical counterpart in the generated output directory.  Also checks that no extra files
+     * were generated that are absent from the golden directory.
+     */
+    private void assertMatchesGolden(File goldenDir, File generatedDir, String label)
+            throws IOException {
+        List<String> errors = new ArrayList<>();
+
+        // Collect relative paths of all .java files in the golden directory
+        List<String> goldenRelPaths = collectJavaPaths(goldenDir.toPath());
+
+        // Collect relative paths of all .java files in the generated output directory
+        List<String> generatedRelPaths = collectJavaPaths(generatedDir.toPath());
+
+        // Files present in golden but missing from generated output
+        List<String> missingFromGenerated = new ArrayList<>(goldenRelPaths);
+        missingFromGenerated.removeAll(generatedRelPaths);
+        for (String missing : missingFromGenerated) {
+            errors.add("[" + label + "] Missing generated file: " + missing);
+        }
+
+        // Extra files in generated output that are not in golden
+        List<String> extraInGenerated = new ArrayList<>(generatedRelPaths);
+        extraInGenerated.removeAll(goldenRelPaths);
+        for (String extra : extraInGenerated) {
+            errors.add("[" + label + "] Unexpected generated file (not in golden): " + extra);
+        }
+
+        // Compare content of files present in both
+        for (String relPath : goldenRelPaths) {
+            if (!generatedRelPaths.contains(relPath)) {
+                continue; // already reported as missing above
+            }
+            File goldenFile = new File(goldenDir, relPath);
+            File generatedFile = new File(generatedDir, relPath);
+            compareFileContent(goldenFile, generatedFile, relPath, label, errors);
+        }
+
+        if (!errors.isEmpty()) {
+            fail(errors.size() + " golden file assertion(s) failed:\n"
+                    + String.join("\n", errors));
+        }
+    }
+
+    private List<String> collectJavaPaths(Path root) throws IOException {
+        if (!root.toFile().exists()) {
+            return new ArrayList<>();
+        }
+        try (Stream<Path> stream = Files.walk(root)) {
+            return stream
+                    .filter(p -> p.toString().endsWith(".java"))
+                    .map(p -> root.relativize(p).toString())
+                    .sorted()
+                    .collect(Collectors.toList());
+        }
+    }
+
+    private void compareFileContent(File goldenFile, File generatedFile, String relPath,
+            String label, List<String> errors) throws IOException {
+        List<String> goldenLines = Files.readAllLines(goldenFile.toPath());
+        List<String> generatedLines = Files.readAllLines(generatedFile.toPath());
+
+        int maxLines = Math.max(goldenLines.size(), generatedLines.size());
+        for (int i = 0; i < maxLines; i++) {
+            String goldenLine = i < goldenLines.size() ? goldenLines.get(i) : "<EOF>";
+            String generatedLine = i < generatedLines.size() ? generatedLines.get(i) : "<EOF>";
+            if (!goldenLine.equals(generatedLine)) {
+                errors.add(String.format(
+                        "[%s] %s line %d differs:%n  golden:    %s%n  generated: %s",
+                        label, relPath, i + 1, goldenLine, generatedLine));
+                // Report only the first differing line per file to keep output manageable
+                break;
+            }
+        }
+        if (goldenLines.size() != generatedLines.size() && errors.isEmpty()) {
+            // Line counts differ but all shared lines matched – report the length mismatch
+            errors.add(String.format(
+                    "[%s] %s line count differs: golden=%d, generated=%d",
+                    label, relPath, goldenLines.size(), generatedLines.size()));
+        }
+    }
+}

quickfixj-codegenerator/src/test/resources/golden/README.md

@@ -0,0 +1,76 @@
+# Golden Files for Code Generator Regression Tests
+
+This directory contains the reference ("golden") output of `MessageCodeGenerator`
+for **FIX42** and **FIX44**.  They are used by `GoldenFileTest` to catch
+unintended changes to generated code.
+
+## Directory layout
+
+```
+golden/
+  fix42/   – output generated from quickfixj-messages-fix42/src/main/resources/FIX42.xml
+  fix44/   – output generated from quickfixj-messages-fix44/src/main/resources/FIX44.xml
+```
+
+## What the test does
+
+`GoldenFileTest` runs `MessageCodeGenerator` against both dictionaries into a
+temporary folder, then walks every `.java` file and asserts line-by-line equality
+with the corresponding file here.  Missing or extra files also fail the test.
+
+## When the generator output changes intentionally
+
+1. Make your generator changes.
+2. Rebuild the module to pick up the new code:
+   ```bash
+   ./mvnw package -pl quickfixj-codegenerator -DskipTests
+   ```
+3. Regenerate the golden files by running the generator against both dictionaries
+   from the `quickfixj-codegenerator` directory:
+   ```bash
+   # FIX42
+   java -cp "target/quickfixj-codegenerator-*-SNAPSHOT.jar:$(./mvnw -q dependency:build-classpath -DincludeScope=compile -Dmdep.outputFile=/dev/stdout)" \
+        org.quickfixj.codegenerator.MessageCodeGenerator \
+        --spec ../quickfixj-messages/quickfixj-messages-fix42/src/main/resources/FIX42.xml \
+        --transform src/main/resources/org/quickfixj/codegenerator \
+        --out src/test/resources/golden/fix42 \
+        --messagePackage quickfix.fix42 --fieldPackage quickfix.field \
+        --orderedFields --decimal
+   ```
+   The easiest way is to use the existing `GoldenFileTest` parameters as a guide
+   and write a small standalone `main` — or simply copy the generated output from
+   the temporary folder that `GoldenFileTest` creates (set a breakpoint, or change
+   `tempFolder` to a fixed path temporarily).
+
+   Alternatively, run the following Maven snippet from the repo root, which uses
+   the same settings as the test:
+   ```bash
+   ./mvnw test -pl quickfixj-codegenerator -Dtest=GenerateGoldenFilesManual
+   ```
+   *(Create a one-off test class that calls the generator and copies output to
+   `src/test/resources/golden/` if you prefer a scripted approach.)*
+
+4. Verify only the expected files changed:
+   ```bash
+   git diff --stat quickfixj-codegenerator/src/test/resources/golden/
+   ```
+5. Run the full test suite to confirm the updated golden files now match:
+   ```bash
+   ./mvnw test -pl quickfixj-codegenerator
+   ```
+6. Commit the updated golden files **together with your generator changes** in the
+   same commit (or PR) so reviewers can see the diff side-by-side.
+
+## Why FIX42 and FIX44?
+
+| Coverage area          | FIX42 | FIX44 |
+|------------------------|-------|-------|
+| Fields                 | ✓     | ✓     |
+| Messages               | ✓     | ✓     |
+| Components             |       | ✓     |
+| Repeating groups       | ✓ (38)| ✓ (233, incl. nested) |
+| Message cracker/factory| ✓     | ✓     |
+
+FIX42 is small enough to keep test times short while still exercising the
+group-generation path.  FIX44's 233 groups (including nested groups relevant to
+issue #1084) provide thorough coverage without needing all FIX versions.

quickfixj-codegenerator/src/test/resources/golden/fix42/quickfix/field/Account.java

@@ -0,0 +1,38 @@
+/* Generated Java Source File */
+/*******************************************************************************
+ * Copyright (c) quickfixengine.org  All rights reserved.
+ *
+ * This file is part of the QuickFIX FIX Engine
+ *
+ * This file may be distributed under the terms of the quickfixengine.org
+ * license as defined by quickfixengine.org and appearing in the file
+ * LICENSE included in the packaging of this file.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
+ * THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE.
+ *
+ * See http://www.quickfixengine.org/LICENSE for licensing information.
+ *
+ * Contact ask@quickfixengine.org if any conditions of this licensing
+ * are not clear to you.
+ ******************************************************************************/
+
+package quickfix.field;
+
+import quickfix.StringField;
+
+public class Account extends StringField {
+
+    static final long serialVersionUID = 20050617;
+
+    public static final int FIELD = 1;
+    
+    public Account() {
+        super(1);
+    }
+
+    public Account(String data) {
+        super(1, data);
+    }
+}

quickfixj-codegenerator/src/test/resources/golden/fix42/quickfix/field/AccruedInterestAmt.java

@@ -0,0 +1,42 @@
+/* Generated Java Source File */
+/*******************************************************************************
+ * Copyright (c) quickfixengine.org  All rights reserved.
+ *
+ * This file is part of the QuickFIX FIX Engine
+ *
+ * This file may be distributed under the terms of the quickfixengine.org
+ * license as defined by quickfixengine.org and appearing in the file
+ * LICENSE included in the packaging of this file.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
+ * THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE.
+ *
+ * See http://www.quickfixengine.org/LICENSE for licensing information.
+ *
+ * Contact ask@quickfixengine.org if any conditions of this licensing
+ * are not clear to you.
+ ******************************************************************************/
+
+package quickfix.field;
+
+import quickfix.DecimalField;
+
+public class AccruedInterestAmt extends DecimalField {
+
+    static final long serialVersionUID = 20050617;
+
+    public static final int FIELD = 159;
+    
+    public AccruedInterestAmt() {
+        super(159);
+    }
+
+    public AccruedInterestAmt(java.math.BigDecimal data) {
+        super(159, data);
+    }
+
+    public AccruedInterestAmt(double data) {
+        super(159, new java.math.BigDecimal(data));
+    }
+}

quickfixj-codegenerator/src/test/resources/golden/fix42/quickfix/field/AccruedInterestRate.java

@@ -0,0 +1,38 @@
+/* Generated Java Source File */
+/*******************************************************************************
+ * Copyright (c) quickfixengine.org  All rights reserved.
+ *
+ * This file is part of the QuickFIX FIX Engine
+ *
+ * This file may be distributed under the terms of the quickfixengine.org
+ * license as defined by quickfixengine.org and appearing in the file
+ * LICENSE included in the packaging of this file.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
+ * THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE.
+ *
+ * See http://www.quickfixengine.org/LICENSE for licensing information.
+ *
+ * Contact ask@quickfixengine.org if any conditions of this licensing
+ * are not clear to you.
+ ******************************************************************************/
+
+package quickfix.field;
+
+import quickfix.DoubleField;
+
+public class AccruedInterestRate extends DoubleField {
+
+    static final long serialVersionUID = 20050617;
+
+    public static final int FIELD = 158;
+    
+    public AccruedInterestRate() {
+        super(158);
+    }
+
+    public AccruedInterestRate(double data) {
+        super(158, data);
+    }
+}