Refactor download handling and improve test management

backend/src/main/java/com/devaulty/backend/application/impl/release/DownloadUpdateImpl.java

@@ -11,7 +11,7 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.nio.channels.AsynchronousFileChannel;
+import java.io.OutputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
@@ -94,27 +94,37 @@ private Flux<UpdateProgressInfo> startDownloadProcess(String downloadUrl, long t
         );
 
         return Flux.using(
-                () -> AsynchronousFileChannel.open(
+                () -> Files.newOutputStream(
                         targetPath,
                         StandardOpenOption.CREATE,
                         StandardOpenOption.WRITE,
                         StandardOpenOption.TRUNCATE_EXISTING
                 ),
 
-                fileChannel -> {
+                outputStream -> {
                     Flux<UpdateProgressInfo> downloadProgress = releasePort.downloadAsset(downloadUrl)
                             .timeout(DOWNLOAD_TIMEOUT)
                             .concatMap(dataBuffer -> {
-                                int chunkSize = dataBuffer.readableByteCount();
-                                long currentTotal = downloadedBytes.addAndGet(chunkSize);
-                                int percentage = knownSize ? (int) ((currentTotal * 100) / totalBytes) : 0;
-
-                                UpdateProgressInfo progressInfo = new UpdateProgressInfo(
-                                        UpdateStatus.DOWNLOADING, percentage, currentTotal, totalBytes, null
-                                );
-
-                                return DataBufferUtils.write(Flux.just(dataBuffer), fileChannel)
-                                        .then(Mono.just(progressInfo));
+                                try {
+                                    int chunkSize = dataBuffer.readableByteCount();
+
+                                    // Write the buffer contents to the output stream
+                                    byte[] bytes = new byte[chunkSize];
+                                    dataBuffer.read(bytes);
+                                    outputStream.write(bytes);
+
+                                    long currentTotal = downloadedBytes.addAndGet(chunkSize);
+                                    int percentage = knownSize ? (int) ((currentTotal * 100) / totalBytes) : 0;
+
+                                    return Mono.just(new UpdateProgressInfo(
+                                            UpdateStatus.DOWNLOADING, percentage, currentTotal, totalBytes, null
+                                    ));
+                                } catch (IOException e) {
+                                    return Mono.error(e);
+                                } finally {
+                                    // Always release the DataBuffer to prevent Netty ByteBuf leaks
+                                    DataBufferUtils.release(dataBuffer);
+                                }
                             })
                             .distinctUntilChanged(p -> knownSize ? p.percentage() : p.downloadedBytes())
                             .sample(PROGRESS_SAMPLE_INTERVAL)
@@ -126,7 +136,6 @@ private Flux<UpdateProgressInfo> startDownloadProcess(String downloadUrl, long t
                                     null
                             ))));
 
-
                     Mono<UpdateProgressInfo> installAndComplete = Mono
                             .fromRunnable(() -> installUpdateUseCase.execute(targetPath))
                             .subscribeOn(Schedulers.boundedElastic())
@@ -151,7 +160,7 @@ private Flux<UpdateProgressInfo> startDownloadProcess(String downloadUrl, long t
                             .concatWith(installAndComplete);
                 },
 
-                this::closeChannel
+                this::closeOutputStream
         ).onErrorResume(ex -> deleteQuietly(targetPath)
                 .then(Mono.just(new UpdateProgressInfo(
                         UpdateStatus.FAILED, 0, downloadedBytes.get(), totalBytes, ex.getMessage()
@@ -169,12 +178,13 @@ private Mono<Void> deleteQuietly(Path path) {
         });
     }
 
-    private void closeChannel(AsynchronousFileChannel channel) {
-        if (channel != null && channel.isOpen()) {
+    private void closeOutputStream(OutputStream outputStream) {
+        if (outputStream != null) {
             try {
-                channel.close();
+                outputStream.flush();
+                outputStream.close();
             } catch (Exception ignored) {
-                // Defensive channel closure
+                // Defensive stream closure
             }
         }
     }

backend/src/main/java/com/devaulty/backend/application/impl/release/InstallUpdateImpl.java

@@ -80,10 +80,13 @@ private void launchLinuxInstaller(String filePath, long currentPid) throws IOExc
         // Wait for the current process to exit, install the package with pkexec,
         // then relaunch the app fully detached (nohup + setsid) so it survives
         // after the installer script exits.
+        // Uses ";" instead of "&&" so the app always relaunches, even if the
+        // installation fails — the previous version is still installed and
+        // should remain usable.
         String script =
                 "PID=\"$1\"; FILE=\"$2\"; PROGRAM=\"$3\"; FLAG=\"$4\"; " +
                         "while kill -0 \"$PID\" 2>/dev/null; do sleep 0.2; done; " +
-                        "pkexec \"$PROGRAM\" \"$FLAG\" \"$FILE\" && " +
+                        "pkexec \"$PROGRAM\" \"$FLAG\" \"$FILE\"; " +
                         "nohup setsid devaulty >/dev/null 2>&1 &";
 
         List<String> command = List.of(
@@ -95,11 +98,16 @@ private void launchLinuxInstaller(String filePath, long currentPid) throws IOExc
     }
 
     private void launchMacInstaller(String filePath, long currentPid) throws IOException {
-        // Read the note about limitations at the top of the class
+        // Read the note about limitations at the top of the class.
+        // After mounting the DMG the app is always relaunched so the user is
+        // not left without a running instance.  The relaunch starts the
+        // currently-installed version; the user still needs to manually copy
+        // the new .app from the mounted image into /Applications.
         String script =
                 "PID=\"$1\"; FILE=\"$2\"; " +
                         "while kill -0 \"$PID\" 2>/dev/null; do sleep 0.2; done; " +
-                        "open \"$FILE\"";
+                        "open \"$FILE\"; " +
+                        "sleep 2; open -a Devaulty";
 
         List<String> command = List.of(
                 "bash", "-c", script, "bash",

backend/src/main/java/com/devaulty/backend/application/impl/release/ReleaseTempFolder.java

@@ -8,12 +8,22 @@
  * {@link InstallUpdateImpl} must resolve the same directory so that the
  * installer file written by the download step can be located by the install
  * step without path mismatches.
+ * Can be overridden via {@code -Ddevaulty.temp.dir} (e.g. in tests for isolation).
  */
 public final class ReleaseTempFolder {
 
     private ReleaseTempFolder() {}
 
     public static File resolve() {
+        String customDir = System.getProperty("devaulty.temp.dir");
+        if (customDir != null && !customDir.isBlank()) {
+            File tempDir = new File(customDir);
+            if (!tempDir.exists()) {
+                tempDir.mkdirs();
+            }
+            return tempDir;
+        }
+
         String userHome = System.getProperty("user.home");
         String os = System.getProperty("os.name").toLowerCase();
 

backend/src/main/resources/application.yaml

@@ -1,5 +1,5 @@
 app:
-  version: "0.1.4-alpha"
+  version: "0.1.5-alpha"
 
 spring:
   application:

backend/src/test/java/com/devaulty/backend/application/impl/release/DownloadUpdateImplTest.java

@@ -7,16 +7,20 @@
 import com.devaulty.backend.application.port.in.release.UpdateProgressInfo;
 import com.devaulty.backend.application.port.in.release.enums.UpdateStatus;
 import com.devaulty.backend.application.port.out.external.release.ReleasePort;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import reactor.core.publisher.Flux;
 
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
 import java.time.Instant;
 import java.util.List;
 
@@ -27,6 +31,9 @@
 @ExtendWith(MockitoExtension.class)
 class DownloadUpdateImplTest {
 
+    @TempDir
+    Path tempFolder;
+
     @Mock
     private ReleasePort releasePort;
 
@@ -39,6 +46,16 @@ class DownloadUpdateImplTest {
     @InjectMocks
     private DownloadUpdateImpl downloadUpdateUseCase;
 
+    @BeforeEach
+    void setUp() {
+        System.setProperty("devaulty.temp.dir", tempFolder.toString());
+    }
+
+    @AfterEach
+    void tearDown() {
+        System.clearProperty("devaulty.temp.dir");
+    }
+
     @Test
     @DisplayName("Should throw UpdateNotAvailableException when updateAvailable is false")
     void shouldThrowUpdateNotAvailableException_whenNoUpdateAvailable() {

backend/src/test/java/com/devaulty/backend/application/impl/release/InstallUpdateImplTest.java

@@ -1,9 +1,12 @@
 package com.devaulty.backend.application.impl.release;
 
 import com.devaulty.backend.application.exception.UpdateNotAvailableException;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.io.TempDir;
 import org.mockito.Mock;
 import org.mockito.Spy;
 import org.mockito.junit.jupiter.MockitoExtension;
@@ -21,12 +24,25 @@
 @ExtendWith(MockitoExtension.class)
 class InstallUpdateImplTest {
 
+    @TempDir
+    Path tempFolder;
+
     @Mock
     private ConfigurableApplicationContext applicationContext;
 
     @Spy
     private InstallUpdateImpl installUpdateUseCase = new InstallUpdateImpl(applicationContext);
 
+    @BeforeEach
+    void setUp() {
+        System.setProperty("devaulty.temp.dir", tempFolder.toString());
+    }
+
+    @AfterEach
+    void tearDown() {
+        System.clearProperty("devaulty.temp.dir");
+    }
+
     @Test
     @DisplayName("Should throw UpdateNotAvailableException when installer file does not exist")
     void shouldThrowUpdateNotAvailableException_whenInstallerFileDoesNotExist() {
@@ -52,26 +68,9 @@ void shouldThrowIllegalStateException_whenInstallerFileOutsideTempDir() throws I
     @DisplayName("Should launch installer process without executing real system commands during unit tests")
     void shouldLaunchInstallerProcess_withoutExecutingRealSystemCommands() throws IOException {
         // Arrange
-        String userHome = System.getProperty("user.home");
-        String os = System.getProperty("os.name").toLowerCase();
-        File tempDir;
-        if (os.contains("win")) {
-            String localAppData = System.getenv("LOCALAPPDATA");
-            File base = localAppData != null ? new File(localAppData) : new File(userHome, "AppData/Local");
-            tempDir = new File(base, "devaulty/temp");
-        } else if (os.contains("mac")) {
-            tempDir = new File(userHome, "Library/Caches/devaulty/temp");
-        } else {
-            tempDir = new File(userHome, ".config/devaulty/temp");
-        }
-
-        if (!tempDir.exists()) {
-            tempDir.mkdirs();
-        }
-
+        File tempDir = tempFolder.toFile();
         File testInstaller = new File(tempDir, "test_installer.deb");
         testInstaller.createNewFile();
-        testInstaller.deleteOnExit();
 
         // Prevent real pkexec / msiexec execution during unit test by mocking startDetached
         doNothing().when(installUpdateUseCase).startDetached(anyList());

frontend/src/components/RootLayout.tsx

@@ -17,8 +17,10 @@ import {
   useCheckUpdatesMutation,
 } from "~features/releases/hooks/useReleases";
 import { UpdateModal } from "~features/releases/components/UpdateModal";
+import { formatVersionTag } from "../utils/versionUtils";
 import type { AppUpdateInfoResponse } from "~types/api";
 
+
 // ──────────────────────────────────────────────────────────────
 // Edge toggle button — floats half in / half out of the sidebar.
 // Uses a CSS custom property so its `left` transitions in sync
@@ -65,13 +67,14 @@ const NavigationSidebar: React.FC<{
   const activeProjects = projects.filter((p) => !p.archived);
 
   const handleManualCheck = async () => {
+
     try {
       const res = await checkUpdatesMutation.mutateAsync();
       if (res.updateAvailable) {
         onOpenUpdateModal(res);
       } else {
         toast.success(
-          `Devaulty is up to date (v${res.currentVersion || versionData?.actualVersion || ""})`
+          `Devaulty is up to date (${formatVersionTag(res.currentVersion || versionData?.actualVersion)})`
         );
       }
     } catch {
@@ -102,7 +105,8 @@ const NavigationSidebar: React.FC<{
                 className="text-[10px] font-mono text-muted-foreground/70 hover:text-foreground transition-colors border border-border/40 px-2 py-0.5 rounded-full bg-secondary/20 cursor-pointer flex items-center gap-1"
                 title="Click to check for updates"
               >
-                <span>v{versionData.actualVersion}</span>
+                <span>{formatVersionTag(versionData.actualVersion)}</span>
+
                 {checkUpdatesMutation.isPending && (
                   <Icons.Loader2 size={10} className="animate-spin text-primary" />
                 )}

frontend/src/features/releases/components/UpdateModal.module.css

@@ -158,14 +158,72 @@
   border-radius: var(--radius-md, 8px);
   padding: 1rem;
   font-size: 0.82rem;
-  line-height: 1.5;
+  line-height: 1.6;
   color: var(--color-foreground, #cbd5e1);
-  max-height: 180px;
+  max-height: 220px;
   overflow-y: auto;
-  white-space: pre-wrap;
   overflow-wrap: anywhere;
 }
 
+.releaseNotesContent p {
+  margin: 0 0 0.5rem 0;
+}
+
+.releaseNotesContent p:last-child {
+  margin-bottom: 0;
+}
+
+.releaseNotesContent a {
+  color: var(--color-primary, #6366f1);
+  text-decoration: underline;
+  word-break: break-all;
+  transition: color 0.15s ease;
+}
+
+.releaseNotesContent a:hover {
+  color: #818cf8;
+}
+
+.releaseNotesContent strong,
+.releaseNotesContent b {
+  color: #f3f4f6;
+  font-weight: 600;
+}
+
+.releaseNotesContent ul,
+.releaseNotesContent ol {
+  margin: 0.25rem 0 0.5rem 1.25rem;
+  padding: 0;
+}
+
+.releaseNotesContent li {
+  margin-bottom: 0.25rem;
+}
+
+.releaseNotesContent code {
+  font-family: var(--font-mono, monospace);
+  background: rgba(255, 255, 255, 0.1);
+  padding: 0.15rem 0.35rem;
+  border-radius: 4px;
+  font-size: 0.78rem;
+  color: #a5b4fc;
+}
+
+.releaseNotesContent pre {
+  background: #090d16;
+  border: 1px solid rgba(255, 255, 255, 0.1);
+  border-radius: 6px;
+  padding: 0.75rem;
+  overflow-x: auto;
+  margin: 0.5rem 0;
+}
+
+.releaseNotesContent pre code {
+  background: transparent;
+  padding: 0;
+}
+
+
 /* Progress & Installation State */
 .progressSection {
   display: flex;