Add test for text files

pmd-core/src/main/java/net/sourceforge/pmd/lang/document/TextFile.java

@@ -212,7 +212,24 @@ public interface TextFile extends Closeable {
      *
      * @throws NullPointerException If any parameter is null
      */
-    static TextFileBuilder forReader(Reader reader, String pathId, LanguageVersion languageVersion) {
+    static TextFile forReader(Reader reader, String pathId, LanguageVersion languageVersion) {
+        return builderForReader(reader, pathId, languageVersion).build();
+    }
+
+    /**
+     * Returns a read-only builder reading from a reader.
+     * The reader is first read when {@link TextFile#readContents()} is first
+     * called, and is closed when that method exits. Note that this may
+     * only be called once, afterwards, {@link TextFile#readContents()} will
+     * throw an {@link IOException}.
+     *
+     * @param reader          Text of the file
+     * @param pathId          File name to use as path id
+     * @param languageVersion Language version
+     *
+     * @throws NullPointerException If any parameter is null
+     */
+    static TextFileBuilder builderForReader(Reader reader, String pathId, LanguageVersion languageVersion) {
         return new ForReader(languageVersion, reader, pathId);
     }
 

pmd-core/src/main/java/net/sourceforge/pmd/util/treeexport/TreeExportCli.java

@@ -188,7 +188,7 @@ public class TreeExportCli {
             throw bail("One of --file or --read-stdin must be mentioned");
         } else if (readStdin) {
             io.stderr.println("Reading from stdin...");
-            textFile = TextFile.forReader(readFromSystemIn(), "stdin", langVersion).build();
+            textFile = TextFile.forReader(readFromSystemIn(), "stdin", langVersion);
         } else {
             textFile = TextFile.forPath(Paths.get(file), Charset.forName(encoding), langVersion);
         }

pmd-core/src/test/java/net/sourceforge/pmd/lang/document/TextFilesTest.java

@@ -0,0 +1,96 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.document;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.apache.commons.io.IOUtils;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import net.sourceforge.pmd.lang.DummyLanguageModule;
+import net.sourceforge.pmd.lang.LanguageVersion;
+
+public class TextFilesTest {
+
+    @Rule
+    public TemporaryFolder tempDir = TemporaryFolder.builder().build();
+
+    private LanguageVersion dummyVersion = DummyLanguageModule.getInstance().getDefaultVersion();
+
+    @Test
+    public void testNioFile() throws IOException {
+        Path file = makeTmpFile(StandardCharsets.UTF_8, "some content");
+        try (TextFile tf = TextFile.forPath(file, StandardCharsets.UTF_8, dummyVersion)) {
+            Assert.assertEquals(file.toAbsolutePath().toString(), tf.getPathId());
+            Assert.assertEquals(file.toString(), tf.getDisplayName());
+            Assert.assertEquals(dummyVersion, tf.getLanguageVersion());
+            Assert.assertEquals(Chars.wrap("some content"), tf.readContents().getNormalizedText());
+        }
+    }
+
+    @Test
+    public void testNioFileBuilder() throws IOException {
+        Path file = makeTmpFile(StandardCharsets.UTF_8, "some content");
+        try (TextFile tf = TextFile.builderForPath(file, StandardCharsets.UTF_8, dummyVersion)
+                                   .withDisplayName("aname")
+                                   .build()) {
+            Assert.assertEquals(file.toAbsolutePath().toString(), tf.getPathId());
+            Assert.assertEquals("aname", tf.getDisplayName());
+            Assert.assertEquals(dummyVersion, tf.getLanguageVersion());
+            Assert.assertEquals(Chars.wrap("some content"), tf.readContents().getNormalizedText());
+        }
+    }
+
+    @Test
+    public void testNioFileEscape() throws IOException {
+        Path file = makeTmpFile(StandardCharsets.UTF_8, "some\r\ncontent");
+        try (TextFile tf = TextFile.forPath(file, StandardCharsets.UTF_8, dummyVersion)) {
+            Assert.assertEquals(Chars.wrap("some\ncontent"), tf.readContents().getNormalizedText());
+        }
+    }
+
+    @Test
+    public void testReaderFileEscape() throws IOException {
+        Path file = makeTmpFile(StandardCharsets.UTF_8, "some\r\ncontent");
+        try (TextFile tf = TextFile.forReader(Files.newBufferedReader(file, StandardCharsets.UTF_8), "filename", dummyVersion)) {
+            Assert.assertEquals("filename", tf.getPathId());
+            Assert.assertEquals("filename", tf.getDisplayName());
+            Assert.assertEquals(dummyVersion, tf.getLanguageVersion());
+            Assert.assertEquals(Chars.wrap("some\ncontent"), tf.readContents().getNormalizedText());
+            Assert.assertThrows(ReadOnlyFileException.class, () -> tf.writeContents(
+                TextFileContent.fromCharSeq("new content")
+            ));
+        }
+    }@Test
+    public void testStringFileEscape() throws IOException {
+        try (TextFile tf = TextFile.forCharSeq("cont\r\nents", "filename", dummyVersion)) {
+            Assert.assertEquals("filename", tf.getPathId());
+            Assert.assertEquals("filename", tf.getDisplayName());
+            Assert.assertEquals(dummyVersion, tf.getLanguageVersion());
+            Assert.assertEquals(Chars.wrap("cont\r\nent"), tf.readContents().getNormalizedText());
+            Assert.assertThrows(ReadOnlyFileException.class, () -> tf.writeContents(
+                TextFileContent.fromCharSeq("new content")
+            ));
+        }
+    }
+
+    private @NonNull Path makeTmpFile(Charset charset, String content) throws IOException {
+        Path file = tempDir.newFile().toPath();
+        try (BufferedWriter writer = Files.newBufferedWriter(file, charset)) {
+            IOUtils.write(content, writer);
+        }
+        return file;
+    }
+
+}