Fix handling of file: module URIs with non-ASCII characters (#696)

Addresses an issue where Pkl cannot evaluate files with non-ASCII characters.

pkl-core/src/main/java/org/pkl/core/StackFrameTransformers.java

@@ -18,7 +18,6 @@ package org.pkl.core;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.nio.file.Path;
 import java.util.stream.StreamSupport;
 import org.pkl.core.packages.PackageAssetUri;
 import org.pkl.core.runtime.VmContext;
@@ -93,7 +92,7 @@ public final class StackFrameTransformers {
       var uri = frame.getModuleUri();
       if (!uri.startsWith("file:")) return frame;
 
-      return transformUri(frame, Path.of(URI.create(uri)).toString(), scheme);
+      return transformUri(frame, IoUtils.pathOf(URI.create(uri)).toString(), scheme);
     };
   }
 

pkl-core/src/main/java/org/pkl/core/module/FileResolver.java

@@ -24,12 +24,13 @@ import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import org.pkl.core.util.IoUtils;
 
 public final class FileResolver {
   private FileResolver() {}
 
   public static List<PathElement> listElements(URI baseUri) throws IOException {
-    return listElements(Path.of(baseUri));
+    return listElements(IoUtils.pathOf(baseUri));
   }
 
   public static List<PathElement> listElements(Path path) throws IOException {
@@ -49,7 +50,7 @@ public final class FileResolver {
   }
 
   public static boolean hasElement(URI elementUri) {
-    return Files.exists(Path.of(elementUri));
+    return Files.exists(IoUtils.pathOf(elementUri));
   }
 
   public static boolean hasElement(Path path) {

pkl-core/src/main/java/org/pkl/core/module/ModuleKeys.java

@@ -16,7 +16,6 @@
 package org.pkl.core.module;
 
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
-import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
@@ -26,7 +25,6 @@ import java.net.URISyntaxException;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse.BodyHandlers;
 import java.nio.charset.StandardCharsets;
-import java.nio.file.Path;
 import java.util.List;
 import java.util.Map;
 import org.pkl.core.SecurityManager;
@@ -325,7 +323,7 @@ public final class ModuleKeys {
       if (java.io.File.separatorChar == '\\' && uriPath != null && uriPath.contains("\\")) {
         throw new FileNotFoundException();
       }
-      var realPath = Path.of(uri).toRealPath();
+      var realPath = IoUtils.pathOf(uri).toRealPath();
       var resolvedUri = realPath.toUri();
       securityManager.checkResolveModule(resolvedUri);
       return ResolvedModuleKeys.file(this, resolvedUri, realPath);

pkl-core/src/main/java/org/pkl/core/util/IoUtils.java

@@ -88,6 +88,20 @@ public final class IoUtils {
     return new URI(null, null, str, null);
   }
 
+  /** Converts a URI to a Path, normalizing any non-ASCII characters. */
+  public static Path pathOf(URI uri) {
+    // Path.of(URI) throws on non-ASCII characters so the module URI here must be normalized to
+    // ASCII
+    // Unfortunately there's no way to go from URI -> ASCII URI directly
+    // so this must transform URI -> ASCII String -> ASCII URI
+    try {
+      return Path.of(new URI(uri.toASCIIString()));
+    } catch (URISyntaxException e) {
+      // impossible to get here; we started from a valid URI to begin with
+      throw PklBugException.unreachableCode();
+    }
+  }
+
   /** Like {@link #toUri(String)}, except without checked exceptions. */
   public static URI createUri(String str) {
     try {