test(mpconfig): Have DirConfigSource.findDir() covered by tests.

Introducing some mocks to enable unit testing of findDir().
Needed to extend the base class constructors to be able to inject the mock.

Relates to payara#5006

P.S. Crossing fingers this runs on Windoze.

nucleus/payara-modules/nucleus-microprofile/config-service/src/main/java/fish/payara/nucleus/microprofile/config/source/DirConfigSource.java

@@ -39,6 +39,7 @@
  */
 package fish.payara.nucleus.microprofile.config.source;
 
+import fish.payara.nucleus.microprofile.config.spi.ConfigProviderResolverImpl;
 import org.eclipse.microprofile.config.spi.ConfigSource;
 
 import java.io.File;
@@ -231,8 +232,9 @@ public DirConfigSource() {
     }
 
     // Used for testing only with explicit dependency injection
-    DirConfigSource(Path directory) {
-        super(true);
+    // Used for testing only with explicit dependency injection
+    DirConfigSource(Path directory, ConfigProviderResolverImpl configService) {
+        super(configService);
         this.directory = directory;
     }
 
@@ -274,7 +276,7 @@ public String getName() {
         return "Directory";
     }
 
-    private Path findDir() throws IOException {
+    Path findDir() throws IOException {
         String path = configService.getMPConfig().getSecretDir();
         List<Path> candidates = new ArrayList<>();
 

nucleus/payara-modules/nucleus-microprofile/config-service/src/main/java/fish/payara/nucleus/microprofile/config/source/PayaraConfigSource.java

@@ -67,4 +67,12 @@ public PayaraConfigSource() {
         configService = null;
     }
 
+    /**
+     * Should only be used for test purposes
+     * @param configService Usually a mocked implementation
+     */
+    PayaraConfigSource(ConfigProviderResolverImpl configService) {
+        this.domainConfiguration = null;
+        this.configService = configService;
+    }
 }

nucleus/payara-modules/nucleus-microprofile/config-service/src/test/java/fish/payara/nucleus/microprofile/config/source/DirConfigSourceTest.java

@@ -39,6 +39,8 @@
  */
 package fish.payara.nucleus.microprofile.config.source;
 
+import fish.payara.nucleus.microprofile.config.spi.ConfigProviderResolverImpl;
+import fish.payara.nucleus.microprofile.config.spi.MicroprofileConfigConfiguration;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -65,18 +67,21 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.*;
 
 public class DirConfigSourceTest {
 
     private static Path testDirectory;
     private static DirConfigSource source;
     private static ScheduledExecutorService exec = Executors.newScheduledThreadPool(3);
+    private static ConfigProviderResolverImpl configService;
 
     @BeforeClass
     public static void setUp() throws IOException {
         testDirectory = Files.createTempDirectory("microprofile-config-test-");
+        configService = mock(ConfigProviderResolverImpl.class);
         // create & load
-        source = new DirConfigSource(testDirectory);
+        source = new DirConfigSource(testDirectory, configService);
     }
 
     @AfterClass
@@ -89,6 +94,33 @@ public static void tearDown() throws IOException, InterruptedException {
             .forEach(File::delete);
     }
 
+    @Test
+    public void testFindDir_AbsolutePath() throws IOException {
+        // given
+        MicroprofileConfigConfiguration config = mock(MicroprofileConfigConfiguration.class);
+        when(configService.getMPConfig()).thenReturn(config);
+        when(config.getSecretDir()).thenReturn(testDirectory.toString());
+        // when
+        Path sut = source.findDir();
+        // then
+        assertEquals(testDirectory, sut);
+    }
+
+    @Test
+    public void testFindDir_RelativePath() throws IOException {
+        // given
+        System.setProperty("com.sun.aas.instanceRoot", testDirectory.toString());
+        MicroprofileConfigConfiguration config = mock(MicroprofileConfigConfiguration.class);
+        when(configService.getMPConfig()).thenReturn(config);
+        when(config.getSecretDir()).thenReturn(".");
+
+        // when
+        Path sut = source.findDir();
+
+        // then
+        assertEquals(testDirectory, sut);
+    }
+
     @Test
     public void testIsAptDir() throws IOException {
         // given