test: cover case-insensitive resource path collisions

src/test/java/com/reandroid/apk/PathSanitizerCaseInsensitiveTest.java

@@ -0,0 +1,93 @@
+package com.reandroid.apk;
+
+import com.reandroid.archive.InputSource;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Set;
+
+public class PathSanitizerCaseInsensitiveTest {
+
+    private static InputSource source(final String name) {
+        return new InputSource(name) {
+            @Override
+            public InputStream openStream() {
+                return new ByteArrayInputStream(
+                    name.getBytes(java.nio.charset.StandardCharsets.UTF_8)
+                );
+            }
+        };
+    }
+
+    private static int countCollisions(List<InputSource> sources) {
+        Set<String> names = new HashSet<>();
+        int collisions = 0;
+        for (InputSource source : sources) {
+            String key = source.getAlias()
+                .toLowerCase(Locale.ROOT);
+            if (!names.add(key)) {
+                collisions++;
+            }
+        }
+        return collisions;
+    }
+
+    @Test
+    public void testCaseInsensitivePaths() throws Exception {
+        List<InputSource> sources = new ArrayList<>();
+
+        sources.add(source("res/Zy.xml"));
+        sources.add(source("res/zy.xml"));
+        sources.add(source("res/-n.xml"));
+        sources.add(source("res/-N.xml"));
+        sources.add(source("res/1b.xml"));
+        sources.add(source("res/1B.xml"));
+        sources.add(source("res/unique.xml"));
+
+        int originalCount = sources.size();
+
+        Assert.assertEquals(3, countCollisions(sources));
+
+        PathSanitizer sanitizer = new PathSanitizer(sources);
+        sanitizer.setCaseInsensitive(true);
+        sanitizer.sanitize();
+
+        Assert.assertEquals(originalCount, sources.size());
+        Assert.assertEquals(0, countCollisions(sources));
+
+        for (InputSource source : sources) {
+            Assert.assertNotNull(source.getAlias());
+            Assert.assertFalse(source.getAlias().isEmpty());
+            Assert.assertEquals(
+                source.getName(),
+                new String(
+                    readBytes(source.openStream()),
+                    java.nio.charset.StandardCharsets.UTF_8
+                )
+            );
+        }
+
+        System.out.println("Case-insensitive regression test passed");
+    }
+
+    private static byte[] readBytes(java.io.InputStream input)
+            throws java.io.IOException {
+        try (java.io.InputStream in = input;
+             java.io.ByteArrayOutputStream out =
+                 new java.io.ByteArrayOutputStream()) {
+            byte[] buffer = new byte[8192];
+            int count;
+            while ((count = in.read(buffer)) != -1) {
+                out.write(buffer, 0, count);
+            }
+            return out.toByteArray();
+        }
+    }
+
+}