Fix some bugs in PathFileObject, add test pack

- Mark methods in PathFileObject as raising NoSuchFileException rather than FileNotFoundException
  which was previously incorrect information.
- Fix bug where the 'name' of a PathFileObject could previously have been an absolute path
  if the PathFileObject was initialised with an absolute file path. Now it will match the
  string representation of the relative path on the object.
- Rename getRoot to the clearer 'getRootPath' which is consistent with other
  method naming in this class.
- Update IllegalArgumentException that is thrown if a root path is not absolute
  so that it conveys the value of the erroneous parameter in the error message.
- Implement tests for PathFileObject.

Author: ascopes

java-compiler-testing/src/main/java/io/github/ascopes/jct/filemanagers/PathFileObject.java

@@ -23,7 +23,6 @@
 import java.io.BufferedOutputStream;
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -37,6 +36,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.FileSystem;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import javax.annotation.Nullable;
 import javax.annotation.WillNotClose;
@@ -90,7 +90,7 @@ public PathFileObject(Location location, Path rootPath, Path relativePath) {
     requireNonNull(relativePath, "relativePath");
 
     if (!rootPath.isAbsolute()) {
-      throw new IllegalArgumentException("rootPath must be absolute");
+      throw new IllegalArgumentException("Expected rootPath to be absolute, but got " + rootPath);
     }
 
     this.location = location;
@@ -101,7 +101,7 @@ public PathFileObject(Location location, Path rootPath, Path relativePath) {
         : relativePath;
 
     fullPath = rootPath.resolve(relativePath);
-    name = relativePath.toString();
+    name = this.relativePath.toString();
     uri = fullPath.toUri();
     kind = FileUtils.pathToKind(relativePath);
   }
@@ -138,8 +138,8 @@ public boolean equals(@Nullable Object other) {
    * Get the class access level, where appropriate.
    *
    * <p>In this implementation, this class will always return {@code null}, since this
-   * information is not readily available without preloading the file in question and
-   * parsing it first.
+   * information is not readily available without preloading the file in question and parsing it
+   * first.
    *
    * <p>At the time of writing, the OpenJDK implementations of the JavaFileObject class
    * do not provide an implementation for this method either.
@@ -227,8 +227,8 @@ public String getName() {
    * Determine the class nesting kind, where appropriate.
    *
    * <p>In this implementation, this class will always return {@code null}, since this
-   * information is not readily available without preloading the file in question and
-   * parsing it first.
+   * information is not readily available without preloading the file in question and parsing it
+   * first.
    *
    * <p>At the time of writing, the OpenJDK implementations of the JavaFileObject class
    * do not provide an implementation for this method either.
@@ -255,7 +255,7 @@ public Path getRelativePath() {
    *
    * @return the root path.
    */
-  public Path getRoot() {
+  public Path getRootPath() {
     return rootPath;
   }
 
@@ -295,8 +295,8 @@ public boolean isNameCompatible(String simpleName, Kind kind) {
    * <p>The returned implementation will always be buffered.
    *
    * @return a buffered input stream.
-   * @throws FileNotFoundException if the file does not exist.
-   * @throws IOException           if an IO error occurs.
+   * @throws NoSuchFileException if the file does not exist.
+   * @throws IOException         if an IO error occurs.
    */
   @Override
   @WillNotClose
@@ -315,7 +315,6 @@ public BufferedInputStream openInputStream() throws IOException {
    *
    * <p>The returned implementation will always be buffered.
    *
-   *
    * @return a buffered output stream.
    * @throws IOException if an IO error occurs.
    */
@@ -336,8 +335,8 @@ public BufferedOutputStream openOutputStream() throws IOException {
    * @param ignoreEncodingErrors {@code true} to suppress encoding errors, or {@code false} to throw
    *                             them to the caller.
    * @return a buffered reader.
-   * @throws FileNotFoundException if the file does not exist.
-   * @throws IOException           if an IO error occurs.
+   * @throws NoSuchFileException if the file does not exist.
+   * @throws IOException         if an IO error occurs.
    */
   @Override
   @WillNotClose
@@ -351,7 +350,7 @@ public BufferedReader openReader(boolean ignoreEncodingErrors) throws IOExceptio
   /**
    * Open a writer to this file using the default charset (UTF-8).
    *
-   * <p>This will Ccreate the file first if it does not already exist. If it does exist,
+   * <p>This will create the file first if it does not already exist. If it does exist,
    * this will first overwrite the file and truncate it.
    *
    * <p>This input stream must be closed once finished with, otherwise

java-compiler-testing/src/test/java/io/github/ascopes/jct/tests/helpers/Fixtures.java

@@ -418,6 +418,31 @@ public static Path somePath() {
     return root.resolve("some-dummy-path");
   }
 
+  /**
+   * Get some dummy absolute path.
+   *
+   * @return some dummy absolute path.
+   */
+  public static Path someAbsolutePath() {
+    return somePath().resolve("some-absolute-path").toAbsolutePath();
+  }
+
+  /**
+   * Get some relative path.
+   *
+   * @return some dummy relative path.
+   */
+  public static Path someRelativePath() {
+    var absolutePath = someAbsolutePath();
+    var relativePath = absolutePath;
+
+    for (var i = 0; i < someInt(1, 4); ++i) {
+      relativePath = absolutePath.resolve(someText());
+    }
+
+    return absolutePath.relativize(relativePath.resolve("some-relative-path"));
+  }
+
   /**
    * Get some module reference.
    *
@@ -521,7 +546,6 @@ private TempFileSystem() {
           .setAttributeViews("basic", "posix")
           .setRoots("/")
           .setWorkingDirectory("/")
-          .setPathEqualityUsesCanonicalForm(true)
           .build();
 
       fs = Jimfs.newFileSystem(name, config);