Add linesOf variants for a Path content (#2618)

src/main/java/org/assertj/core/api/Assertions.java

@@ -104,6 +104,7 @@
 import org.assertj.core.util.CanIgnoreReturnValue;
 import org.assertj.core.util.CheckReturnValue;
 import org.assertj.core.util.Files;
+import org.assertj.core.util.Paths;
 import org.assertj.core.util.URLs;
 import org.assertj.core.util.introspection.FieldSupport;
 import org.assertj.core.util.introspection.Introspection;
@@ -169,7 +170,7 @@ public static <T> PredicateAssert<T> assertThat(Predicate<T> actual) {
     return AssertionsForInterfaceTypes.assertThat(actual);
   }
 
-  
+
   /**
    * Create assertion for {@link Predicate}.
    * <p>
@@ -2842,6 +2843,54 @@ public static List<String> linesOf(File file, String charsetName) {
     return Files.linesOf(file, charsetName);
   }
 
+  /**
+   * Loads the text content of a file at a given path into a list of strings with the default charset, each string corresponding to a
+   * line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path) {
+    return Paths.linesOf(path, Charset.defaultCharset());
+  }
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charset the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path, Charset charset) {
+    return Paths.linesOf(path, charset);
+  }
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line. The line endings are
+   * either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charsetName the name of the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path, String charsetName) {
+    return Paths.linesOf(path, charsetName);
+  }
+
   // --------------------------------------------------------------------------------------------------
   // URL/Resource methods : not assertions but here to have a single entry point to all AssertJ features.
   // --------------------------------------------------------------------------------------------------

src/main/java/org/assertj/core/api/AssertionsForClassTypes.java

@@ -21,6 +21,7 @@
 import java.net.URI;
 import java.net.URL;
 import java.nio.charset.Charset;
+import java.nio.file.Path;
 import java.text.DateFormat;
 import java.time.Duration;
 import java.time.Instant;
@@ -38,8 +39,8 @@
 import java.util.OptionalInt;
 import java.util.OptionalLong;
 import java.util.concurrent.CompletableFuture;
-
 import java.util.regex.Matcher;
+
 import org.assertj.core.api.ThrowableAssert.ThrowingCallable;
 import org.assertj.core.api.filter.FilterOperator;
 import org.assertj.core.api.filter.Filters;
@@ -60,6 +61,7 @@
 import org.assertj.core.util.CanIgnoreReturnValue;
 import org.assertj.core.util.CheckReturnValue;
 import org.assertj.core.util.Files;
+import org.assertj.core.util.Paths;
 import org.assertj.core.util.URLs;
 import org.assertj.core.util.introspection.FieldSupport;
 
@@ -1652,6 +1654,54 @@ public static List<String> linesOf(File file, String charsetName) {
     return Files.linesOf(file, charsetName);
   }
 
+  /**
+   * Loads the text content of a path into a list of strings with the default charset, each string corresponding to a
+   * line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @return the content of the file.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path) {
+    return Paths.linesOf(path, Charset.defaultCharset());
+  }
+
+  /**
+   * Loads the text content of a path into a list of strings, each string corresponding to a line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charset the character set to use.
+   * @return the content of the file.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path, Charset charset) {
+    return Paths.linesOf(path, charset);
+  }
+
+  /**
+   * Loads the text content of a path into a list of strings, each string corresponding to a line. The line endings are
+   * either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charsetName the name of the character set to use.
+   * @return the content of the file.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  public static List<String> linesOf(Path path, String charsetName) {
+    return Paths.linesOf(path, charsetName);
+  }
+
   // --------------------------------------------------------------------------------------------------
   // URL/Resource methods : not assertions but here to have a single entry point to all AssertJ features.
   // --------------------------------------------------------------------------------------------------

src/main/java/org/assertj/core/api/BDDAssertions.java

@@ -3338,6 +3338,54 @@ public static List<String> linesOf(File file, String charsetName) {
     return Assertions.linesOf(file, charsetName);
   }
 
+	/**
+	 * Loads the text content of a file at a given path into a list of strings with the default charset, each string corresponding to a
+	 * line.
+	 * The line endings are either \n, \r or \r\n.
+	 *
+	 * @param path the path.
+	 * @return the content of the file at the given path.
+	 * @throws NullPointerException if the given charset is {@code null}.
+	 * @throws UncheckedIOException if an I/O exception occurs.
+	 *
+	 * @since 3.23.0
+	 */
+	public static List<String> linesOf(Path path) {
+		return Assertions.linesOf(path, Charset.defaultCharset());
+	}
+
+	/**
+	 * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line.
+	 * The line endings are either \n, \r or \r\n.
+	 *
+	 * @param path the path.
+	 * @param charset the character set to use.
+	 * @return the content of the file at the given path.
+	 * @throws NullPointerException if the given charset is {@code null}.
+	 * @throws UncheckedIOException if an I/O exception occurs.
+	 *
+	 * @since 3.23.0
+	 */
+	public static List<String> linesOf(Path path, Charset charset) {
+		return Assertions.linesOf(path, charset);
+	}
+
+	/**
+	 * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line. The line endings are
+	 * either \n, \r or \r\n.
+	 *
+	 * @param path the path.
+	 * @param charsetName the name of the character set to use.
+	 * @return the content of the file at the given path.
+	 * @throws NullPointerException if the given charset is {@code null}.
+	 * @throws UncheckedIOException if an I/O exception occurs.
+	 *
+	 * @since 3.23.0
+	 */
+	public static List<String> linesOf(Path path, String charsetName) {
+		return Assertions.linesOf(path, charsetName);
+	}
+
   // --------------------------------------------------------------------------------------------------
   // URL/Resource methods : not assertions but here to have a single entry point to all AssertJ features.
   // --------------------------------------------------------------------------------------------------

src/main/java/org/assertj/core/api/WithAssertions.java

@@ -2067,6 +2067,54 @@ default List<String> linesOf(final File file, final Charset charset) {
     return Assertions.linesOf(file, charset);
   }
 
+  /**
+   * Loads the text content of a file at a given path into a list of strings with the default charset, each string corresponding to a
+   * line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  default List<String> linesOf(final Path path) {
+    return Assertions.linesOf(path);
+  }
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line. The line endings are
+   * either \n, \r or \r\n.
+   *
+   * @param path the file.
+   * @param charsetName the name of the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  default List<String> linesOf(final Path path, final String charsetName) {
+    return Assertions.linesOf(path, charsetName);
+  }
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line.
+   * The line endings are either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charset the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   *
+   * @since 3.23.0
+   */
+  default List<String> linesOf(final Path path, final Charset charset) {
+    return Assertions.linesOf(path, charset);
+  }
+
   /**
    * Sets whether we remove elements related to AssertJ from assertion error stack trace.
    *

src/main/java/org/assertj/core/util/Files.java

@@ -288,12 +288,7 @@ public static String contentOf(File file, Charset charset) {
    * @throws UncheckedIOException if an I/O exception occurs.
    */
   public static List<String> linesOf(File file, Charset charset) {
-    requireNonNull(charset, "The charset should not be null");
-    try {
-      return java.nio.file.Files.readAllLines(file.toPath(), charset);
-    } catch (IOException e) {
-      throw new UncheckedIOException("Unable to read " + file.getAbsolutePath(), e);
-    }
+    return Paths.linesOf(file.toPath(), charset);
   }
 
   /**
@@ -307,8 +302,7 @@ public static List<String> linesOf(File file, Charset charset) {
    * @throws UncheckedIOException if an I/O exception occurs.
    */
   public static List<String> linesOf(File file, String charsetName) {
-    checkArgumentCharsetIsSupported(charsetName);
-    return linesOf(file, Charset.forName(charsetName));
+    return Paths.linesOf(file.toPath(), charsetName);
   }
 
   private static void checkArgumentCharsetIsSupported(String charsetName) {

src/main/java/org/assertj/core/util/Paths.java

@@ -0,0 +1,73 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * Copyright 2012-2022 the original author or authors.
+ */
+package org.assertj.core.util;
+
+import static java.util.Objects.requireNonNull;
+import static org.assertj.core.util.Preconditions.checkArgument;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+/**
+ * Utility methods related to {@link Path}s.
+ *
+ * @author Stefan Bratanov
+ *
+ * @since 3.23.0
+ */
+public class Paths {
+
+  private Paths() {}
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line. The line endings are
+   * either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charset the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   */
+  public static List<String> linesOf(Path path, Charset charset) {
+    requireNonNull(charset, "The charset should not be null");
+    try {
+      return Files.readAllLines(path, charset);
+    } catch (IOException e) {
+      throw new UncheckedIOException("Unable to read " + path, e);
+    }
+  }
+
+  /**
+   * Loads the text content of a file at a given path into a list of strings, each string corresponding to a line. The line endings are
+   * either \n, \r or \r\n.
+   *
+   * @param path the path.
+   * @param charsetName the name of the character set to use.
+   * @return the content of the file at the given path.
+   * @throws NullPointerException if the given charset is {@code null}.
+   * @throws UncheckedIOException if an I/O exception occurs.
+   */
+  public static List<String> linesOf(Path path, String charsetName) {
+    checkArgumentCharsetIsSupported(charsetName);
+    return linesOf(path, Charset.forName(charsetName));
+  }
+
+  private static void checkArgumentCharsetIsSupported(String charsetName) {
+    checkArgument(Charset.isSupported(charsetName), "Charset:<'%s'> is not supported on this system", charsetName);
+  }
+}

src/test/java/org/assertj/core/api/Assertions_linesOf_Test.java

@@ -18,6 +18,8 @@
 
 import java.io.File;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
@@ -33,4 +35,11 @@ void should_read_lines_of_file_with_UTF8_charset() {
     assertThat(linesOf(file, StandardCharsets.UTF_8)).isEqualTo(EXPECTED_CONTENT);
   }
 
+  @Test
+  void should_read_lines_of_path_with_UTF8_charset() {
+    Path path = Paths.get("src", "test", "resources", "utf8.txt");
+    assertThat(linesOf(path, "UTF-8")).isEqualTo(EXPECTED_CONTENT);
+    assertThat(linesOf(path, StandardCharsets.UTF_8)).isEqualTo(EXPECTED_CONTENT);
+  }
+
 }