CLDR-14139 Filename collisions

tools/cldr-code/src/test/java/org/unicode/cldr/unittest/TestFilenameCollisions.java

@@ -0,0 +1,56 @@
+package org.unicode.cldr.unittest;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.TreeMultimap;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Locale;
+import java.util.Map.Entry;
+import org.unicode.cldr.icu.dev.test.TestFmwk;
+import org.unicode.cldr.util.CLDRPaths;
+
+public class TestFilenameCollisions extends TestFmwk {
+    public static void main(String[] args) {
+        new TestFilenameCollisions().run(args);
+    }
+
+    /**
+     * Test for filename collisions. This include exact matches, but also cases that are easily
+     * confusable:<br>
+     * case-insensitive matches, and names with "test" either at the start or end.
+     *
+     * @throws IOException
+     */
+    public void testUniqueness() throws IOException {
+        Path root = Path.of(CLDRPaths.BASE_DIRECTORY);
+        Multimap<String, Path> mmap = TreeMultimap.create();
+        Files.walk(root)
+                .forEach(
+                        x -> {
+                            String name = x.getName(x.getNameCount() - 1).toString();
+                            if (name.endsWith(".java")) {
+                                name =
+                                        name.substring(0, name.length() - 5)
+                                                .toLowerCase(Locale.ROOT);
+                                if (name.endsWith("test")) {
+                                    name = "test" + name.substring(0, name.length() - 4);
+                                }
+                                if (!name.equals("testall")) {
+                                    mmap.put(name, root.relativize(x));
+                                }
+                            }
+                        });
+        for (Entry<String, Collection<Path>> entry : mmap.asMap().entrySet()) {
+            Collection<Path> filenames = entry.getValue();
+            if (!assertEquals(
+                    "files with same name-skeleton «" + entry.getKey() + "»",
+                    1,
+                    filenames.size())) {
+                System.out.println(Joiner.on("\n").join(filenames));
+            }
+        }
+    }
+}