Add a CLI to convert message files

java/cli/pom.xml

@@ -0,0 +1,102 @@
+<?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>
+
+    <parent>
+        <groupId>io.cucumber</groupId>
+        <artifactId>junit-xml-formatter-parent</artifactId>
+        <version>0.5.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>junit-xml-formatter-cli</artifactId>
+    <packaging>jar</packaging>
+    <name>JUnit XML Formatter CLI</name>
+    <description>CLI to render Cucumber Messages as JUnit XML</description>
+    <url>https://github.com/cucumber/junit-xml-formatter</url>
+
+    <properties>
+        <java.version>21</java.version>
+        <project.Automatic-Module-Name>io.cucumber.junitxmlformatter.cli</project.Automatic-Module-Name>
+    </properties>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.junit</groupId>
+                <artifactId>junit-bom</artifactId>
+                <version>5.11.3</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+
+            <dependency>
+                <groupId>com.fasterxml.jackson</groupId>
+                <artifactId>jackson-bom</artifactId>
+                <version>2.18.0</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>info.picocli</groupId>
+            <artifactId>picocli</artifactId>
+            <version>4.7.6</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.cucumber</groupId>
+            <artifactId>junit-xml-formatter</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jdk8</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.module</groupId>
+            <artifactId>jackson-module-parameter-names</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.26.3</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <mainClass>io.cucumber.junitxmlformatter.cli.JunitXmlFormatter</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

java/cli/src/main/java/io/cucumber/junitxmlformatter/cli/JunitXmlFormatter.java

@@ -0,0 +1,179 @@
+package io.cucumber.junitxmlformatter.cli;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.cfg.ConstructorDetector;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;
+import com.fasterxml.jackson.module.paramnames.ParameterNamesModule;
+import io.cucumber.junitxmlformatter.MessagesToJunitXmlWriter;
+import io.cucumber.messages.NdjsonToMessageIterable;
+import io.cucumber.messages.NdjsonToMessageIterable.Deserializer;
+import io.cucumber.messages.types.Envelope;
+import io.cucumber.query.NamingStrategy.ExampleName;
+import picocli.CommandLine;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.Model.CommandSpec;
+import picocli.CommandLine.Option;
+import picocli.CommandLine.ParameterException;
+import picocli.CommandLine.Parameters;
+import picocli.CommandLine.Spec;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.Callable;
+
+import static io.cucumber.junitxmlformatter.cli.JunitXmlFormatter.*;
+import static java.nio.file.Files.newOutputStream;
+import static java.nio.file.StandardOpenOption.CREATE;
+import static java.nio.file.StandardOpenOption.TRUNCATE_EXISTING;
+
+@Command(
+        name = JUNIT_XML_FORMATTER_NAME,
+        mixinStandardHelpOptions = true,
+        header = "Converts Cucumber messages to JUnit XML",
+        versionProvider = ManifestVersionProvider.class
+)
+class JunitXmlFormatter implements Callable<Integer> {
+    static final String JUNIT_XML_FORMATTER_NAME = "junit-xml-formatter";
+
+    @Spec
+    private CommandSpec spec;
+
+    @Parameters(
+            index = "0",
+            paramLabel = "file",
+            description = "The input file containing Cucumber messages. " +
+                    "Use - to read from the standard input."
+    )
+    private Path source;
+
+    @Option(
+            names = {"-o", "--output"},
+            arity = "0..1",
+            paramLabel = "file",
+            description = "The output file containing JUnit XML. " +
+                    "If file is a directory, a new file be " +
+                    "created by taking the name of the input file and " +
+                    "replacing the suffix with '.xml'. If the file is omitted " +
+                    "the current working directory is used."
+    )
+    private Path output;
+
+    @Option(
+            names = {"-e","--example-naming-strategy"},
+            paramLabel = "strategy",
+            description = "How to name examples. Valid values: ${COMPLETION-CANDIDATES}",
+            defaultValue = "NUMBER_AND_PICKLE_IF_PARAMETERIZED"
+    )
+    private ExampleName exampleNameStrategy;
+
+    @Override
+    public Integer call() throws IOException {
+        if (isSourceSystemIn()) {
+            if (isDestinationDirectory()) {
+                throw new ParameterException(
+                        spec.commandLine(),
+                        ("Invalid value '%s' for option '--output': When " +
+                                "reading from standard input, output can not " +
+                                "be a directory").formatted(output)
+                );
+            }
+        }
+
+        try (var envelopes = new NdjsonToMessageIterable(sourceInputStream(), deserializer());
+             var writer = new MessagesToJunitXmlWriter(exampleNameStrategy, outputPrintWriter())
+        ) {
+            for (var envelope : envelopes) {
+                // TODO: What if exception while writing?
+                writer.write(envelope);
+            }
+        }
+        return 0;
+    }
+
+    public static void main(String... args) {
+        var exitCode = new CommandLine(new JunitXmlFormatter()).execute(args);
+        System.exit(exitCode);
+    }
+
+    private boolean isSourceSystemIn() {
+        return source.getFileName().toString().equals("-");
+    }
+
+    private boolean isDestinationDirectory() {
+        return output != null && Files.isDirectory(output);
+    }
+
+    private static Deserializer deserializer() {
+        var jsonMapper = JsonMapper.builder()
+                .addModule(new Jdk8Module())
+                .addModule(new ParameterNamesModule(JsonCreator.Mode.PROPERTIES))
+                .constructorDetector(ConstructorDetector.USE_PROPERTIES_BASED)
+                .enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING)
+                .enable(DeserializationFeature.USE_LONG_FOR_INTS)
+                .disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
+                .build();
+        return json -> jsonMapper.readValue(json, Envelope.class);
+    }
+
+    private PrintWriter outputPrintWriter() {
+        if (output == null) {
+            return spec.commandLine().getOut();
+        }
+        Path path = outputPath();
+        try {
+            return new PrintWriter(
+                    new OutputStreamWriter(
+                            newOutputStream(path, CREATE, TRUNCATE_EXISTING),
+                            StandardCharsets.UTF_8
+                    )
+            );
+        } catch (IOException e) {
+            throw new ParameterException(
+                    spec.commandLine(),
+                    ("Invalid value '%s' for option '--output': Could not " +
+                            "write to '%s'"
+                    ).formatted(output, path), e);
+        }
+    }
+
+    private Path outputPath() {
+        if (!isDestinationDirectory()) {
+            return output;
+        }
+
+        // Given a directory, decide on a file name
+        var fileName = source.getFileName().toString();
+        var index = fileName.lastIndexOf(".");
+        if (index >= 0) {
+            fileName = fileName.substring(0, index);
+        }
+        var candidate = output.resolve(fileName + ".xml");
+
+        // Avoid overwriting existing files when we decided the file name.
+        var counter = 1;
+        while(Files.exists(candidate)) {
+            candidate = output.resolve(fileName + "." + counter + ".xml");
+        }
+        return candidate;
+    }
+
+    private InputStream sourceInputStream() {
+        if (isSourceSystemIn()) {
+            return System.in;
+        }
+        try {
+            return Files.newInputStream(source);
+        } catch (IOException e) {
+            throw new ParameterException(spec.commandLine(), "Invalid argument, could not read '%s'".formatted(source), e);
+        }
+    }
+
+
+}

java/cli/src/main/java/io/cucumber/junitxmlformatter/cli/ManifestVersionProvider.java

@@ -0,0 +1,21 @@
+package io.cucumber.junitxmlformatter.cli;
+
+import picocli.CommandLine.IVersionProvider;
+
+import java.util.Optional;
+import java.util.function.Function;
+
+import static io.cucumber.junitxmlformatter.cli.JunitXmlFormatter.JUNIT_XML_FORMATTER_NAME;
+
+public class ManifestVersionProvider implements IVersionProvider {
+
+    @Override
+    public String[] getVersion() {
+        var version = getAttribute(Package::getImplementationVersion).orElse("DEVELOPMENT");
+        return new String[]{JUNIT_XML_FORMATTER_NAME + " " + version};
+    }
+
+    private static Optional<String> getAttribute(Function<Package, String> function) {
+        return Optional.ofNullable(ManifestVersionProvider.class.getPackage()).map(function);
+    }
+}