Issue checkstyle#12238: Unable to persist cache file if target direct…

…ory is a symbolic link
nrmancuso · Jan 1, 2024 · 2e99389 · 2e99389
1 parent 86b9a28
commit 2e99389
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diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java b/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java
@@ -143,8 +143,21 @@ public void load() throws IOException {
      */
     public void persist() throws IOException {
         final Path path = Paths.get(fileName);
-        final Path directory = path.getParent();
+        Path directory = path.getParent();
+
         if (directory != null) {
+            if (Files.isSymbolicLink(directory)) {
+                final Path actualDir = directory.toRealPath();
+
+                if (Files.isDirectory(actualDir)) {
+                    directory = actualDir;
+                }
+                else {
+                    throw new IOException(
+                            "Resolved symbolic link " + directory
+                                    + " is not a directory.");
+                }
+            }
             Files.createDirectories(directory);
         }
         try (OutputStream out = Files.newOutputStream(path)) {

diff --git a/src/test/java/com/puppycrawl/tools/checkstyle/PropertyCacheFileTest.java b/src/test/java/com/puppycrawl/tools/checkstyle/PropertyCacheFileTest.java
@@ -274,12 +274,97 @@ public void testPathToCacheContainsOnlyFileName() throws IOException {
 
         // no exception expected
         cache.persist();
+
         assertWithMessage("Cache file does not exist")
                 .that(Files.exists(filePath))
                 .isTrue();
         Files.delete(filePath);
     }
 
+    @Test
+    public void testPersistWithSymbolicLinkToDirectory() throws IOException {
+        final Path tempDirectory = Files.createTempDirectory("tempDir");
+        final Path symbolicLinkDirectory = Files.createTempDirectory("symbolicLinkDir")
+                .resolve("symbolicLink");
+        Files.createSymbolicLink(symbolicLinkDirectory, tempDirectory);
+
+        final Configuration config = new DefaultConfiguration("myName");
+        final String cacheFilePath = symbolicLinkDirectory.resolve("cache.temp").toString();
+        final PropertyCacheFile cache = new PropertyCacheFile(config, cacheFilePath);
+
+        cache.persist();
+
+        final Path expectedFilePath = tempDirectory.resolve("cache.temp");
+        assertWithMessage("Cache file should be created in the actual directory")
+                .that(Files.exists(expectedFilePath))
+                .isTrue();
+    }
+
+    @Test
+    public void testSymbolicLinkResolution() throws IOException {
+        final Path tempDirectory = Files.createTempDirectory("tempDir");
+        final Path symbolicLinkDirectory = Files.createTempDirectory("symbolicLinkDir")
+                .resolve("symbolicLink");
+        Files.createSymbolicLink(symbolicLinkDirectory, tempDirectory);
+
+        final Configuration config = new DefaultConfiguration("myName");
+        final String cacheFilePath = symbolicLinkDirectory.resolve("cache.temp").toString();
+        final PropertyCacheFile cache = new PropertyCacheFile(config, cacheFilePath);
+
+        cache.persist();
+
+        final Path expectedFilePath = tempDirectory.resolve("cache.temp");
+        assertWithMessage(
+                "Cache file should be created in the actual directory.")
+                .that(Files.exists(expectedFilePath))
+                .isTrue();
+    }
+
+    @Test
+    public void testSymbolicLinkToNonDirectory() throws IOException {
+        final Path tempFile = Files.createTempFile("tempFile", null);
+        final Path symbolicLinkDirectory = Files.createTempDirectory("symbolicLinkDir");
+        final Path symbolicLink = symbolicLinkDirectory.resolve("symbolicLink");
+        Files.createSymbolicLink(symbolicLink, tempFile);
+
+        final Configuration config = new DefaultConfiguration("myName");
+        final String cacheFilePath = symbolicLink.resolve("cache.temp").toString();
+        final PropertyCacheFile cache = new PropertyCacheFile(config, cacheFilePath);
+
+        final IOException thrown = assertThrows(IOException.class, cache::persist);
+
+        final String expectedMessage = "Resolved symbolic link " + symbolicLink
+                + " is not a directory.";
+
+        assertWithMessage(
+                "Expected IOException when symbolicLink is not a directory")
+                .that(thrown.getMessage())
+                .contains(expectedMessage);
+    }
+
+    @Test
+    public void testMultipleSymbolicLinkResolution() throws IOException {
+        final Path actualDirectory = Files.createTempDirectory("actualDir");
+        final Path firstSymbolicLink = Files.createTempDirectory("firstLinkDir")
+                .resolve("firstLink");
+        Files.createSymbolicLink(firstSymbolicLink, actualDirectory);
+
+        final Path secondSymbolicLink = Files.createTempDirectory("secondLinkDir")
+                .resolve("secondLink");
+        Files.createSymbolicLink(secondSymbolicLink, firstSymbolicLink);
+
+        final Configuration config = new DefaultConfiguration("myName");
+        final String cacheFilePath = secondSymbolicLink.resolve("cache.temp").toString();
+        final PropertyCacheFile cache = new PropertyCacheFile(config, cacheFilePath);
+
+        cache.persist();
+
+        final Path expectedFilePath = actualDirectory.resolve("cache.temp");
+        assertWithMessage("Cache file should be created in the final actual directory")
+                .that(Files.exists(expectedFilePath))
+                .isTrue();
+    }
+
     @Test
     public void testChangeInConfig() throws Exception {
         final DefaultConfiguration config = new DefaultConfiguration("myConfig");