Draft: Test for Writer.of(Appendable)

test/jdk/java/io/Writer/Of.java

@@ -0,0 +1,192 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.Writer;
+import java.io.StringWriter;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.ReadOnlyBufferException;
+import java.util.function.Supplier;
+
+import org.testng.annotations.*;
+
+import static org.testng.Assert.*;
+
+/*
+ * @test
+ * @bug 1234567
+ * @summary Check for expected behavior of Writer.of().
+ * @run testng Of
+ */
+public class Of {
+    private static final String CONTENT = "Some Writer Test";
+
+    private static record Config(String id, Writer writer, Supplier<String> spy) {
+        @Override
+        public String toString() {
+            return id; // allows to identify config when test case fails
+        }
+    };
+
+    /*
+     * Writers to be tested.
+     */
+    @DataProvider
+    public static Config[] writers() {
+        var sw = new StringWriter();
+        var sbuf = new StringBuffer();
+        var sbld = new StringBuilder();
+        var dcb = ByteBuffer.allocateDirect(CONTENT.length() * 2).asCharBuffer();
+        var wcb = CharBuffer.wrap(new char[CONTENT.length()]);
+        var w = new Writer() {
+            String s = "";
+
+            @Override
+            public Writer append(char c) throws IOException {
+                s += c;
+                return this;
+            }
+
+            @Override
+            public Writer append(CharSequence csq) throws IOException {
+                s += String.valueOf(csq);
+                return this;
+            }
+
+            @Override
+            public Writer append(CharSequence csq, int start, int end)
+                    throws IOException {
+                s += String.valueOf(csq).subSequence(start, end);
+                return this;
+            }
+
+            @Override
+            public String toString() {
+                return s;
+            }
+
+            @Override
+            public void write(char[] cbuf, int off, int len) throws IOException {
+                s += new String(cbuf, off, len);
+            }
+
+            @Override
+            public void flush() throws IOException {
+            }
+
+            @Override
+            public void close() throws IOException {
+            }
+        };
+        var a = new Appendable() {
+            String s = "";
+
+            @Override
+            public Appendable append(char c) throws IOException {
+                s += c;
+                return this;
+            }
+
+            @Override
+            public Appendable append(CharSequence csq) throws IOException {
+                s += String.valueOf(csq);
+                return this;
+            }
+
+            @Override
+            public Appendable append(CharSequence csq, int start, int end)
+                    throws IOException {
+                s += String.valueOf(csq).subSequence(start, end);
+                return this;
+            }
+
+            @Override
+            public String toString() {
+                return s;
+            }
+        };
+        return new Config[] {
+            new Config("StringWriter", sw, sw::toString),
+            new Config("StringBuffer", Writer.of(sbuf), sbuf::toString),
+            new Config("StringBuilder", Writer.of(sbld), sbld::toString),
+            new Config("Direct CharBuffer", Writer.of(dcb),
+                    () -> { dcb.flip(); return dcb.toString(); }),
+            new Config("Wrapped CharBuffer", Writer.of(wcb),
+                    () -> { wcb.flip(); return wcb.toString(); }),
+            new Config("Custom Writer", w, w::toString),
+            new Config("Custom Appendable", Writer.of(a), a::toString)
+        };
+    }
+
+    @Test(dataProvider = "writers")
+    public void testAppendChar(Config config) throws IOException {
+        for (int i = 0; i < CONTENT.length(); i++)
+            config.writer.append(CONTENT.charAt(i));
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testAppendCharSequence(Config config) throws IOException {
+        config.writer.append((CharSequence) CONTENT);
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testAppendSubCharSequence(Config config) throws IOException {
+        config.writer.append((CharSequence) CONTENT, 0, CONTENT.length());
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testWriteCharArray(Config config) throws IOException {
+        config.writer.write(CONTENT.toCharArray());
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testWriteSubCharArray(Config config) throws IOException {
+        config.writer.write(CONTENT.toCharArray(), 0, CONTENT.length());
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testWriteChar(Config config) throws IOException {
+        for (int i = 0; i < CONTENT.length(); i++)
+            config.writer.write(CONTENT.charAt(i));
+        assertEquals(config.spy.get(), CONTENT);
+}
+
+    @Test(dataProvider = "writers")
+    public void testWriteString(Config config) throws IOException {
+        config.writer.write(CONTENT);
+        assertEquals(config.spy.get(), CONTENT);
+    }
+
+    @Test(dataProvider = "writers")
+    public void testWriteSubString(Config config) throws IOException {
+        config.writer.write(CONTENT, 0, CONTENT.length());
+        assertEquals(config.spy.get(), CONTENT);
+    }
+}