content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   */
  package org.apache.beam.sdk.io;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.Writer;
  import java.nio.charset.StandardCharsets;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.io.Files;
  import org.junit.Assert;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.TemporaryFolder;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link org.apache.beam.sdk.io.TextRowCountEstimator}. */
  @RunWith(JUnit4.class)
  public class TextRowCountEstimatorTest {
    @Rule public TemporaryFolder temporaryFolder = new TemporaryFolder();
  
    @Test
    public void testNonEmptyFiles() throws Exception {
      File file1 = temporaryFolder.newFile("file1.txt");
      Writer writer = Files.newWriter(file1, StandardCharsets.UTF_8);
      for (int i = 0; i < 100; i++) {
        writer.write("123123123\n");
      }
      writer.flush();
      writer.close();
      temporaryFolder.newFolder("testfolder");
      temporaryFolder.newFolder("testfolder2");
      file1 = temporaryFolder.newFile("testfolder/test2.txt");
      writer = Files.newWriter(file1, StandardCharsets.UTF_8);
      for (int i = 0; i < 50; i++) {
        writer.write("123123123\n");
      }
  
      writer.flush();
      writer.close();
      TextRowCountEstimator textRowCountEstimator =
          TextRowCountEstimator.builder().setFilePattern(temporaryFolder.getRoot() + "/**").build();
      Double rows = textRowCountEstimator.estimateRowCount(PipelineOptionsFactory.create());
      Assert.assertNotNull(rows);
      Assert.assertEquals(150d, rows, 0.01);
    }
  
    @Test(expected = FileNotFoundException.class)
    public void testEmptyFolder() throws Exception {
      TextRowCountEstimator textRowCountEstimator =
          TextRowCountEstimator.builder().setFilePattern(temporaryFolder.getRoot() + "/**").build();
      textRowCountEstimator.estimateRowCount(PipelineOptionsFactory.create());
    }
  
    @Test
    public void testEmptyFile() throws Exception {
      File file1 = temporaryFolder.newFile("file1.txt");
      Writer writer = Files.newWriter(file1, StandardCharsets.UTF_8);
      for (int i = 0; i < 100; i++) {
        writer.write("\n");
      }
      writer.flush();
      writer.close();
      TextRowCountEstimator textRowCountEstimator =
          TextRowCountEstimator.builder().setFilePattern(temporaryFolder.getRoot() + "/**").build();
      Double rows = textRowCountEstimator.estimateRowCount(PipelineOptionsFactory.create());
      Assert.assertEquals(0d, rows, 0.01);
    }
  
    @Test(expected = TextRowCountEstimator.NoEstimationException.class)
    public void lotsOfNewLines() throws Exception {
      File file1 = temporaryFolder.newFile("file1.txt");
      Writer writer = Files.newWriter(file1, StandardCharsets.UTF_8);
      for (int i = 0; i < 1000; i++) {
        writer.write("\n");
      }
      writer.write("123123123");
      writer.flush();
      writer.close();
      TextRowCountEstimator textRowCountEstimator =
          TextRowCountEstimator.builder()
              .setNumSampledBytesPerFile(10L)
              .setFilePattern(temporaryFolder.getRoot() + "/**")
              .build();
      textRowCountEstimator.estimateRowCount(PipelineOptionsFactory.create());
    }
  
    @Test(expected = FileNotFoundException.class)
    public void testNonExistence() throws Exception {
      TextRowCountEstimator textRowCountEstimator =
          TextRowCountEstimator.builder()
              .setFilePattern(temporaryFolder.getRoot() + "/something/**")
              .build();
      Double rows = textRowCountEstimator.estimateRowCount(PipelineOptionsFactory.create());
      Assert.assertNull(rows);
    }
  }
  