[JAVA-5353]: working with tablesaw (#12866)

Co-authored-by: Harpal Singh <harpal.singh@kaleyra.com>

tablesaw/src/test/java/com/baeldung/tablesaw/CSVUnitTest.java

@@ -0,0 +1,146 @@
+package com.baeldung.tablesaw;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import tech.tablesaw.api.DateColumn;
+import tech.tablesaw.api.DoubleColumn;
+import tech.tablesaw.api.StringColumn;
+import tech.tablesaw.api.Table;
+import tech.tablesaw.api.TimeColumn;
+import tech.tablesaw.io.csv.CsvReadOptions;
+import tech.tablesaw.selection.Selection;
+
+import java.io.File;
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatNoException;
+import static tech.tablesaw.aggregate.AggregateFunctions.max;
+import static tech.tablesaw.aggregate.AggregateFunctions.mean;
+import static tech.tablesaw.aggregate.AggregateFunctions.min;
+import static tech.tablesaw.aggregate.AggregateFunctions.stdDev;
+
+class CSVUnitTest {
+
+    private static Table table;
+
+    @BeforeEach
+    void setup() {
+        URL resource = CSVUnitTest.class.getClassLoader().getResource("avocado.csv");
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+        Path filePath = Paths.get(resource.getPath());
+        File file = filePath.toFile();
+        CsvReadOptions csvReadOptions =
+                CsvReadOptions.builder(file)
+                        .separator(',')
+                        .header(true)
+                        .dateFormat(formatter)
+                        .build();
+        table = Table.read().usingOptions(csvReadOptions);
+    }
+
+    @Test
+    void shouldReturnTheShapeStringOnAvocadoDataSet() {
+        assertThat(table.shape()).isEqualTo("avocado.csv: 18249 rows X 14 cols");
+    }
+
+    @Test
+    void shouldOrderTheTableByDateInAscendingOrder() {
+        Table ascendingDateSortedTable = table.sortAscendingOn("Date");
+        assertThat(ascendingDateSortedTable.dateColumn("Date").get(0)).isEqualTo(LocalDate.parse("2015-01-04"));
+    }
+
+    @Test
+    void shouldOrderTheTableByDateInDescendingOrder() {
+        Table descendingDateSortedTable = table.sortDescendingOn("Date");
+        assertThat(descendingDateSortedTable.dateColumn("Date").get(0)).isEqualTo(LocalDate.parse("2018-03-25"));
+    }
+
+    @Test
+    void shouldOrderTheTableByYearAndAveragePriceInAscendingOrder() {
+        Table ascendingYearAndAveragePriceSortedTable = table.sortOn("year", "-AveragePrice");
+        assertThat(ascendingYearAndAveragePriceSortedTable.intColumn("year").get(0)).isEqualTo(2015);
+        assertThat(ascendingYearAndAveragePriceSortedTable.numberColumn("AveragePrice").get(0)).isEqualTo(2.79);
+    }
+
+    @Test
+    void shouldRemoveTheValueWhenSettingAsMissing() {
+        DoubleColumn averagePrice = table.doubleColumn("AveragePrice").setMissing(0);
+        assertThat(averagePrice.get(0)).isNull();
+    }
+
+    @Test
+    void shouldAppendDataToTheColumn() {
+        DoubleColumn averagePrice = table.doubleColumn("AveragePrice");
+        averagePrice.append(1.123);
+        assertThat(averagePrice.get(averagePrice.size() - 1)).isEqualTo(1.123);
+    }
+
+    @Test
+    void shouldAppendDataToAveragePriceColumn() {
+        DoubleColumn averagePrice2 = table.doubleColumn("AveragePrice").copy();
+        averagePrice2.setName("AveragePrice2");
+        averagePrice2.append(1.123);
+        assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> table.addColumns(averagePrice2));
+    }
+
+    @Test
+    void shouldReturnTheTableContainingDataFrom2017andAveragePriceIsGreaterThan2Only() {
+        DateColumn dateTable = table.dateColumn("Date");
+        DoubleColumn averagePrice = table.doubleColumn("AveragePrice");
+        Selection selection = dateTable.isInYear(2017).and(averagePrice.isGreaterThan(2D));
+        Table table2017 = table.where(selection);
+        assertThat(table2017.intColumn("year")).containsOnly(2017);
+        assertThat(table2017.doubleColumn("AveragePrice")).allMatch(avrgPrice -> avrgPrice > 2D);
+    }
+
+    @Test
+    void shouldPrintToStandardOutputStatisticsOfAveragePriceByYearData() {
+        Table summary = table.summarize("AveragePrice", max, min, mean, stdDev).by("year");
+        System.out.println(summary.print());
+        Assertions.assertTrue(true);
+    }
+
+    @Test
+    void shouldThrowIllegalArgumentExceptionWhenCreatingTableWithDifferentSizeColumns() {
+        StringColumn type = StringColumn.create("type");
+        StringColumn region = StringColumn.create("region");
+        type.addAll(List.of("Country", "City"));
+        region.append("USA");
+        assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(() -> Table.create(type, region));
+    }
+
+    @Test
+    void shouldNotThrowIllegalArgumentExceptionWhenCreatingTableWithDifferentSameSizeColumns() {
+        StringColumn type = StringColumn.create("type");
+        StringColumn region = StringColumn.create("region");
+        type.addAll(List.of("Country", "City"));
+        region.append("USA");
+        region.appendMissing();
+        assertThatNoException().isThrownBy(() -> Table.create(type, region));
+    }
+
+    @Test
+    void shouldAddColumnToTable() {
+        TimeColumn time = TimeColumn.create("time");
+        Table table = Table.create("test");
+        table.addColumns(time);
+        assertThat(table.columnNames()).contains("time");
+    }
+
+    @Test
+    void shouldBeEqualTwoValuesFromDifferentRowsOnTheTypeColumn() {
+        StringColumn type = table.stringColumn("type");
+        List<String> conventional = type.where(type.isEqualTo("conventional")).asList().stream()
+                .limit(2)
+                .toList();
+        assertThat(conventional.get(0)).isSameAs(conventional.get(1));
+    }
+}