Refactoring: Pull out resolving of configuration files

services/azure-servicebus/deployment/pom.xml

@@ -48,6 +48,10 @@
             <artifactId>quarkus-junit5-internal</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

services/azure-servicebus/deployment/src/main/java/io/quarkiverse/azure/servicebus/deployment/ServiceBusDevServicesConfig.java

@@ -2,8 +2,6 @@
 
 import static io.quarkiverse.azure.servicebus.deployment.ServiceBusDevServicesConfig.PREFIX;
 
-import java.nio.file.Files;
-import java.nio.file.Path;
 import java.util.Optional;
 import java.util.function.BooleanSupplier;
 
@@ -84,10 +82,6 @@ interface EmulatorConfig {
          */
         String DEFAULT_CONFIG_FILE_NAME = "config.json";
 
-        /**
-         * Location in the classpath from where the fallback configuration file can be loaded.
-         */
-        String FALLBACK_CONFIG_FILE_RESOURCE_PATH = "azure/servicebus-emulator/default-config.json";
         String EXAMPLE_CONFIG_FILE_URL = "https://github.com/Azure/azure-service-bus-emulator-installer/blob/main/ServiceBus-Emulator/Config/Config.json";
 
         /**
@@ -117,7 +111,7 @@ interface EmulatorConfig {
         String imageName();
 
         /**
-         * The name of the property to configure a custom Service Bus emulator configuration file location.
+         * The name of the property to configure a custom Service Bus emulator configuration file.
          */
         String CONFIG_KEY_CONFIG_FILE_PATH = PREFIX + ".config-file-path";
 
@@ -138,19 +132,6 @@ interface EmulatorConfig {
          * configuration file</a>
          */
         Optional<String> configFilePath();
-
-        /**
-         * The verified path to a Service Bus emulator configuration file.
-         * The default configuration file is only considered if no {@link #configFilePath()} is configured.
-         *
-         * @return an Optional containing the path to the configuration file
-         *         or an empty Optional if the file does not exist.
-         */
-        default Optional<Path> effectiveConfigFilePath() {
-            return configFilePath().isPresent()
-                    ? configFilePath().map(path -> Path.of(CONFIG_FILE_DIRECTORY, path)).filter(Files::exists)
-                    : Optional.of(Path.of(CONFIG_FILE_DIRECTORY, DEFAULT_CONFIG_FILE_NAME)).filter(Files::exists);
-        }
     }
 
     /**

services/azure-servicebus/deployment/src/main/java/io/quarkiverse/azure/servicebus/deployment/ServiceBusDevServicesProcessor.java

@@ -6,6 +6,7 @@
 import static io.quarkiverse.azure.servicebus.runtime.ServiceBusConfig.CONFIG_KEY_CONNECTION_STRING;
 import static io.quarkiverse.azure.servicebus.runtime.ServiceBusConfig.CONFIG_KEY_NAMESPACE;
 
+import java.io.FileNotFoundException;
 import java.nio.file.Path;
 import java.util.Collections;
 import java.util.List;
@@ -81,7 +82,6 @@ To use the Service Bus Dev Services, you must accept the license terms of the Se
                     SERVICEBUS_EULA_URL, MSSQL_SERVER_EULA_URL, CONFIG_KEY_LICENSE_ACCEPTED, CONFIG_KEY_DEVSERVICE_ENABLED))));
             return true;
         }
-
         return false;
     }
 
@@ -107,7 +107,7 @@ private List<RunningDevService> startServiceBusEmulator(ServiceBusDevServicesCon
         boolean useSharedNetwork = !devServicesSharedNetworkBuildItem.isEmpty();
         log.debug((useSharedNetwork ? "Using" : "Not using") + " a shared network");
 
-        MountableFile configFile = configFile(devServicesConfig.emulator());
+        MountableFile configFile = mountableConfigFile(devServicesConfig.emulator());
         log.debugf("Azure Service Bus emulator uses configuration file at '%s'", configFile.getResolvedPath());
 
         MSSQLServerContainer<?> database = new MSSQLServerContainer<>(devServicesConfig.database().imageName())
@@ -146,36 +146,23 @@ public Integer getMappedPort(int originalPort) {
         return List.of(databaseDevService, emulatorDevService);
     }
 
-    private MountableFile configFile(EmulatorConfig emulatorConfig) {
-        Optional<Path> effectiveConfigFilePath = emulatorConfig.effectiveConfigFilePath();
+    private MountableFile mountableConfigFile(EmulatorConfig emulatorConfig) {
+        try {
+            var emulatorConfigResolver = new ServiceBusEmulatorConfigResolver(emulatorConfig.configFilePath());
+            Optional<MountableFile> mountableConfigFile = emulatorConfigResolver.getMountableConfigFile();
 
-        if (effectiveConfigFilePath.isPresent()) {
-            // either configured location or default location.
-            return MountableFile.forHostPath(effectiveConfigFilePath.get());
-        } else {
-            if (isConfigFilePathConfigured(emulatorConfig)) {
-                throw configurationExceptionForMissingConfigFile(emulatorConfig);
-            } else {
-                return fallbackConfiguration();
+            if (mountableConfigFile.isEmpty()) {
+                logFallbackConfigurationUsage();
             }
-        }
-    }
 
-    private static boolean isConfigFilePathConfigured(EmulatorConfig emulatorConfig) {
-        return emulatorConfig.configFilePath().isPresent();
-    }
-
-    private ConfigurationException configurationExceptionForMissingConfigFile(EmulatorConfig emulatorConfig) {
-        return new ConfigurationException(String.format(
-                """
-                        The Azure Service Bus emulator configuration file was not found at the location specified with '%s'.
-                        Either add a configuration file at '%s/%s' or disable the Service Bus Dev Services with '%s=false'.
-                        """,
-                EmulatorConfig.CONFIG_KEY_CONFIG_FILE_PATH, EmulatorConfig.CONFIG_FILE_DIRECTORY,
-                emulatorConfig.configFilePath().get(), CONFIG_KEY_DEVSERVICE_ENABLED));
+            return mountableConfigFile
+                    .orElse(ServiceBusEmulatorConfigResolver.getFallbackConfiguration());
+        } catch (FileNotFoundException e) {
+            throw configurationExceptionForMissingConfigFile(emulatorConfig);
+        }
     }
 
-    private MountableFile fallbackConfiguration() {
+    private void logFallbackConfigurationUsage() {
         log.warnf(
                 """
                         To use the Dev Services for Azure Service Bus, a configuration file for the Azure Service Bus emulator must be provided.
@@ -186,15 +173,36 @@ private MountableFile fallbackConfiguration() {
                 EmulatorConfig.EXAMPLE_CONFIG_FILE_URL);
         log.warn(
                 "Azure Service Bus emulator launching with a fallback configuration that provides a queue 'queue' and a topic 'topic' with a subscription 'subscription'.");
-        return MountableFile.forClasspathResource(EmulatorConfig.FALLBACK_CONFIG_FILE_RESOURCE_PATH);
+    }
+
+    private static ConfigurationException configurationExceptionForMissingConfigFile(EmulatorConfig emulatorConfig) {
+        return new ConfigurationException(String.format(
+                """
+                        The Azure Service Bus emulator configuration file was not found at the location specified with '%s'.
+                        Either add a configuration file at '%s/%s' or disable the Service Bus Dev Services with '%s=false'.
+                        """,
+                EmulatorConfig.CONFIG_KEY_CONFIG_FILE_PATH, EmulatorConfig.CONFIG_FILE_DIRECTORY,
+                emulatorConfig.configFilePath().get(), CONFIG_KEY_DEVSERVICE_ENABLED));
     }
 
     @BuildStep(onlyIf = { DevServicesConfig.Enabled.class, ServiceBusDevServicesConfig.Enabled.class, IsDevelopment.class })
     public HotDeploymentWatchedFileBuildItem watchEmulatorConfigFile(ServiceBusDevServicesConfig devServicesConfig) {
-        Optional<Path> configFilePath = devServicesConfig.emulator().effectiveConfigFilePath();
+        try {
+            return watchConfigFile(devServicesConfig.emulator());
+        } catch (FileNotFoundException e) {
+            // Configuration errors are treated at dev service startup,
+            // so we can safely ignore them here.
+            return null;
+        }
+    }
+
+    private HotDeploymentWatchedFileBuildItem watchConfigFile(EmulatorConfig emulatorConfig) throws FileNotFoundException {
+        var emulatorConfigResolver = new ServiceBusEmulatorConfigResolver(emulatorConfig.configFilePath());
+
+        Optional<Path> configFile = emulatorConfigResolver.getConfigFile();
 
-        if (configFilePath.isPresent()) {
-            Path path = configFilePath.get();
+        if (configFile.isPresent()) {
+            Path path = configFile.get();
             log.debugf("Watching '%s' for changes", path);
             return new HotDeploymentWatchedFileBuildItem(path.toAbsolutePath().toString());
         } else {

services/azure-servicebus/deployment/src/main/java/io/quarkiverse/azure/servicebus/deployment/ServiceBusEmulatorConfigResolver.java

@@ -0,0 +1,90 @@
+package io.quarkiverse.azure.servicebus.deployment;
+
+import static io.quarkiverse.azure.servicebus.deployment.ServiceBusDevServicesConfig.EmulatorConfig.CONFIG_FILE_DIRECTORY;
+import static io.quarkiverse.azure.servicebus.deployment.ServiceBusDevServicesConfig.EmulatorConfig.DEFAULT_CONFIG_FILE_NAME;
+
+import java.io.FileNotFoundException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+
+import org.testcontainers.utility.MountableFile;
+
+class ServiceBusEmulatorConfigResolver {
+
+    /**
+     * Location in the classpath from where the fallback configuration file can be loaded.
+     */
+    private static final String FALLBACK_CONFIG_FILE_RESOURCE_PATH = "azure/servicebus-emulator/default-config.json";
+
+    private final Path path;
+    private final boolean exists;
+
+    /**
+     * Creates a {@link ServiceBusEmulatorConfigResolver} for the given configuration file path.
+     *
+     * @param configFilePath the config file path to search in the default configuration directory
+     * @throws FileNotFoundException if a config file path was given and the file does not exist
+     *
+     * @see ServiceBusDevServicesConfig.EmulatorConfig#CONFIG_KEY_CONFIG_FILE_PATH
+     */
+    public ServiceBusEmulatorConfigResolver(Optional<String> configFilePath) throws FileNotFoundException {
+        this(configFilePath, CONFIG_FILE_DIRECTORY);
+    }
+
+    /**
+     * Creates a {@link ServiceBusEmulatorConfigResolver} for the given configuration file path in a custom
+     * configuration directory.
+     * For tests only.
+     *
+     * @param configFilePath the config file path to search in {@code configFileDirectory}
+     * @param configFileDirectory the root directory for Service Bus emulator configuration files, relative to the project root
+     * @throws FileNotFoundException if a config file path was given and the file does not exist
+     *
+     * @see ServiceBusDevServicesConfig.EmulatorConfig#CONFIG_KEY_CONFIG_FILE_PATH
+     */
+    ServiceBusEmulatorConfigResolver(Optional<String> configFilePath, String configFileDirectory) throws FileNotFoundException {
+        this.path = Path.of(configFileDirectory, configFilePath.orElse(DEFAULT_CONFIG_FILE_NAME));
+        this.exists = Files.exists(path);
+        if (configFilePath.isPresent() && !exists) {
+            throw new FileNotFoundException(
+                    String.format("Azure Service Bus emulator configuration file '%s' does not exist", path));
+        }
+    }
+
+    /**
+     * Gets the verified {@link Path} to an existing Service Bus emulator configuration file.
+     * <p>
+     * The configuration file is resolved according to these rules:
+     * <ul>
+     * <li>If a config file path is configured and the config file exists, the path
+     * to that file is returned.</li>
+     * <li>If no config file path is configured but a config file exists at the
+     * default location, the path to it is returned.</li>
+     * <li>If no config file path is configured and no default config file exists,
+     * an empty {@link Optional} is returned.</li>
+     * </ul>
+     *
+     * @see ServiceBusDevServicesConfig.EmulatorConfig#CONFIG_KEY_CONFIG_FILE_PATH
+     * @see ServiceBusDevServicesConfig.EmulatorConfig#DEFAULT_CONFIG_FILE_NAME
+     * @see ServiceBusDevServicesConfig.EmulatorConfig#CONFIG_FILE_DIRECTORY
+     */
+    public Optional<Path> getConfigFile() {
+        return exists ? Optional.of(path) : Optional.empty();
+    }
+
+    /**
+     * Returns the Service Bus emulator configuration file as a {@link MountableFile} that can be
+     * mounted into a container.
+     * <p>
+     * Resolution of the config file is delegated to {@link #getConfigFile()}.
+     */
+    public Optional<MountableFile> getMountableConfigFile() {
+        return getConfigFile().map(MountableFile::forHostPath);
+    }
+
+    public static MountableFile getFallbackConfiguration() {
+        return MountableFile.forClasspathResource(FALLBACK_CONFIG_FILE_RESOURCE_PATH);
+    }
+
+}

services/azure-servicebus/deployment/src/test/java/io/quarkiverse/azure/servicebus/deployment/ServiceBusEmulatorConfigResolverTest.java

@@ -0,0 +1,107 @@
+package io.quarkiverse.azure.servicebus.deployment;
+
+import static io.quarkiverse.azure.servicebus.deployment.ServiceBusDevServicesConfig.EmulatorConfig.DEFAULT_CONFIG_FILE_NAME;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+import java.io.FileNotFoundException;
+import java.nio.file.Path;
+import java.util.Optional;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.utility.MountableFile;
+
+class ServiceBusEmulatorConfigResolverTest {
+
+    @Test
+    @DisplayName("Path unconfigured and no file exists at default location")
+    void noDefaultFileExists() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.empty(),
+                "src/test/resources/servicebus-emulator-empty");
+
+        assertThat(configResolver.getConfigFile())
+                .isEmpty();
+    }
+
+    @Test
+    @DisplayName("Path unconfigured but file exists at default location")
+    void fileExistsInDefaultLocation() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.empty(),
+                "src/test/resources/servicebus-emulator");
+
+        assertThat(configResolver.getConfigFile())
+                .hasValueSatisfying(path -> assertThat(path)
+                        .endsWith(Path.of("servicebus-emulator/config.json")));
+    }
+
+    @Test
+    @DisplayName("Path configured to existing file at default location")
+    void fileExistsInDefaultLocationAndIsConfigured() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.of(DEFAULT_CONFIG_FILE_NAME),
+                "src/test/resources/servicebus-emulator");
+
+        assertThat(configResolver.getConfigFile())
+                .hasValueSatisfying(path -> assertThat(path)
+                        .endsWith(Path.of("servicebus-emulator/config.json")));
+    }
+
+    @Test
+    @DisplayName("Path configured to existing file at custom location")
+    void customFileExists() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.of("custom-config.json"),
+                "src/test/resources/servicebus-emulator");
+
+        assertThat(configResolver.getConfigFile())
+                .hasValueSatisfying(path -> assertThat(path)
+                        .endsWith(Path.of("servicebus-emulator/custom-config.json")));
+    }
+
+    @Test
+    @DisplayName("Path configured to non-existent file at default location")
+    void customFileAtDefaultLocationDoesNotExist() {
+        assertThatExceptionOfType(FileNotFoundException.class)
+                .isThrownBy(
+                        () -> new ServiceBusEmulatorConfigResolver(Optional.of(DEFAULT_CONFIG_FILE_NAME),
+                                "src/test/resources/servicebus-emulator-empty"));
+    }
+
+    @Test
+    @DisplayName("Path configured to non-existent file at custom location")
+    void customFileDoesNotExist() {
+        assertThatExceptionOfType(FileNotFoundException.class)
+                .isThrownBy(
+                        () -> new ServiceBusEmulatorConfigResolver(Optional.of("does-not-exist"),
+                                "src/test/resources/servicebus-emulator"));
+    }
+
+    @Test
+    @DisplayName("MountableFile for existing file")
+    void mountableFileForExistingFile() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.of("custom-config.json"),
+                "src/test/resources/servicebus-emulator");
+
+        assertThat(configResolver.getMountableConfigFile())
+                .hasValueSatisfying(mountableFile -> assertThat(mountableFile.getResolvedPath())
+                        .endsWith("custom-config.json"));
+    }
+
+    @Test
+    @DisplayName("MountableFile if no config file exists")
+    void mountableFileForNonExistingFile() throws FileNotFoundException {
+        var configResolver = new ServiceBusEmulatorConfigResolver(Optional.empty(),
+                "src/test/resources/servicebus-emulator-empty");
+
+        assertThat(configResolver.getMountableConfigFile())
+                .isEmpty();
+    }
+
+    @Test
+    @DisplayName("Fallback configuration is loaded from the classpath")
+    void fallbackConfiguration() {
+        MountableFile fallbackConfiguration = ServiceBusEmulatorConfigResolver.getFallbackConfiguration();
+
+        assertThat(fallbackConfiguration.getResolvedPath())
+                .endsWith("default-config.json");
+    }
+}