fix: give better error messages

app.yml

@@ -34,5 +34,6 @@ actions:
   build: ./mvnw spotless:apply package -DskipTests
   run: ./target/binary/bin/jpm
   test: ./mvnw test
+  format: ./mvnw spotless:apply
   buildj: javac -cp {{deps}} -d classes --source-path src/main/java src/main/java/org/codejive/jpm/Main.java
   runj: java -cp classes:{{deps}} org.codejive.jpm.Main

src/main/java/org/codejive/jpm/Main.java

@@ -16,13 +16,15 @@
 import java.io.*;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.nio.file.Path;
 import java.util.*;
 import java.util.concurrent.Callable;
 import java.util.stream.Collectors;
 import org.codejive.jpm.config.UserConfig;
 import org.codejive.jpm.search.Search.Backends;
+import org.codejive.jpm.util.FileUtils;
 import org.codejive.jpm.util.SyncResult;
 import org.codejive.jpm.util.Version;
 import org.jline.consoleui.elements.InputValue;
@@ -612,13 +614,15 @@ String actionName() {
     }
 
     static class DepsMixin {
+        private static final String DEFAULT_DIRECTORY = "deps";
+
         // Cached user configuration loaded from ~/.config/jpm/config.yml or ~/.jpmcfg.yml
         private transient UserConfig userConfig;
 
         @Option(
                 names = {"-d", "--directory"},
                 description = "Directory to copy artifacts to (default: 'deps')")
-        Path directory;
+        String directory;
 
         @Option(
                 names = {"-L", "--no-links"},
@@ -636,7 +640,7 @@ static class DepsMixin {
                 names = {"-c", "--cache"},
                 description =
                         "Directory where downloaded artifacts will be cached (default: value of JPM_CACHE environment variable; whatever is set in Maven's settings.xml or $HOME/.m2/repository")
-        Path cacheDir;
+        String cacheDir;
 
         /**
          * Loads and caches the user configuration. Priority: --config option > JPM_CONFIG env var >
@@ -658,21 +662,19 @@ UserConfig getUserConfig() {
          * @return The cache directory path or null to use Maven default
          */
         Path getCacheDir() {
-            if (cacheDir != null) {
-                return cacheDir;
+            String dir = cacheDir;
+            if (dir == null) {
+                dir = getUserConfig().cache();
             }
-            Path userConfigCache = getUserConfig().cache();
-            if (userConfigCache != null) {
-                return userConfigCache;
+            if (dir == null) {
+                dir = System.getenv("JPM_CACHE");
             }
-            String envCache = System.getenv("JPM_CACHE");
-            if (envCache != null && !envCache.isEmpty()) {
+            if (dir != null && !dir.isEmpty()) {
                 try {
-                    return Path.of(envCache);
+                    return FileUtils.expandHomePath(dir);
                 } catch (InvalidPathException e) {
                     System.err.println(
-                            "Warning: Invalid path in JPM_CACHE environment variable, ignoring: "
-                                    + envCache);
+                            "Warning: The specified cache path is invalid, ignoring: " + dir);
                 }
             }
             return null;
@@ -685,14 +687,28 @@ Path getCacheDir() {
          * @return The directory path
          */
         Path getDirectory() {
-            if (directory != null) {
-                return directory; // User explicitly set via CLI
+            String dir = directory;
+            if (dir == null) {
+                dir = getUserConfig().directory();
+            }
+            if (dir == null) {
+                dir = DEFAULT_DIRECTORY;
+            }
+            if (dir == null || dir.isEmpty()) {
+                return null;
+            }
+            Path result;
+            try {
+                result = FileUtils.expandHomePath(dir);
+            } catch (InvalidPathException e) {
+                throw new IllegalArgumentException(
+                        "The specified output directory path is invalid: " + dir);
             }
-            Path userConfigDir = getUserConfig().directory();
-            if (userConfigDir != null) {
-                return userConfigDir; // From user config
+            if (Files.isRegularFile(result)) {
+                throw new IllegalArgumentException(
+                        "The specified output directory is a file, not a directory: " + dir);
             }
-            return Path.of("deps"); // Hardcoded default
+            return result;
         }
 
         /**
@@ -812,7 +828,7 @@ private static void printStats(SyncResult stats) {
 
     static CommandLine.IExecutionExceptionHandler errorHandler =
             (ex, commandLine, parseResult) -> {
-                System.err.println("Error: " + ex.getMessage());
+                System.err.println("Error: " + ex);
                 if (verbose) {
                     ex.printStackTrace();
                 } else {

src/main/java/org/codejive/jpm/config/UserConfig.java

@@ -15,8 +15,8 @@
  * options.
  */
 public class UserConfig {
-    private Path cache;
-    private Path directory;
+    private String cache;
+    private String directory;
     private Boolean noLinks;
     private final Map<String, String> repositories = new LinkedHashMap<>();
 
@@ -26,11 +26,11 @@ public class UserConfig {
     /** The fallback user config file location. */
     public static final String USER_CONFIG_FILE_FALLBACK = ".jpmcfg.yml";
 
-    public Path cache() {
+    public String cache() {
         return cache;
     }
 
-    public Path directory() {
+    public String directory() {
         return directory;
     }
 
@@ -152,8 +152,7 @@ private static UserConfig readFromReader(Reader in) {
             if (config.containsKey("cache")) {
                 Object cacheObj = config.get("cache");
                 if (cacheObj instanceof String) {
-                    String cachePath = (String) cacheObj;
-                    userConfig.cache = expandHomePath(cachePath);
+                    userConfig.cache = (String) cacheObj;
                 } else {
                     System.err.println(
                             "Warning: 'cache' must be a string path, ignoring: " + cacheObj);
@@ -164,8 +163,7 @@ private static UserConfig readFromReader(Reader in) {
             if (config.containsKey("directory")) {
                 Object dirObj = config.get("directory");
                 if (dirObj instanceof String) {
-                    String dirPath = (String) dirObj;
-                    userConfig.directory = expandHomePath(dirPath);
+                    userConfig.directory = (String) dirObj;
                 } else {
                     System.err.println(
                             "Warning: 'directory' must be a string path, ignoring: " + dirObj);
@@ -207,19 +205,4 @@ private static UserConfig readFromReader(Reader in) {
 
         return userConfig;
     }
-
-    /**
-     * Expands a path starting with "~/" to use the user's home directory. Handles cross-platform
-     * paths.
-     *
-     * @param pathStr The path string to expand
-     * @return A Path with "~/" expanded to the user's home directory
-     */
-    private static Path expandHomePath(String pathStr) {
-        if (pathStr.startsWith("~/")) {
-            String userHome = System.getProperty("user.home");
-            return Paths.get(userHome, pathStr.substring(2));
-        }
-        return Paths.get(pathStr);
-    }
 }

src/main/java/org/codejive/jpm/util/FileUtils.java

@@ -105,4 +105,18 @@ public static Path safePath(String w) {
             return null;
         }
     }
+
+    /**
+     * Expands a path starting with "~/" to use the user's home directory.
+     *
+     * @param pathStr The path string to expand
+     * @return A Path with "~/" expanded to the user's home directory
+     */
+    public static Path expandHomePath(String pathStr) {
+        if (pathStr.startsWith("~/")) {
+            String userHome = System.getProperty("user.home");
+            return Paths.get(userHome, pathStr.substring(2));
+        }
+        return Paths.get(pathStr);
+    }
 }