CSVParserTest.java

package mi.hdm.filesystem;

import jdk.jfr.Description;
import mi.hdm.recipes.Ingredient;
import mi.hdm.recipes.Measurement;
import mi.hdm.recipes.NutritionTable;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;

import java.lang.reflect.Method;
import java.net.URL;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;

class CSVParserTest {
    private final static CSVParser underTest = new CSVParser();
    private static Method splitLine;
    private static Method getColIdxs;

    @BeforeAll
    public static void setupAll() throws NoSuchMethodException {
        //make private methods accessible for testing
        splitLine = underTest.getClass().getDeclaredMethod("splitLine", String.class, char.class);
        splitLine.setAccessible(true);
        getColIdxs = underTest.getClass().getDeclaredMethod("getColumnIndexes", String.class, char.class, String[].class);
        getColIdxs.setAccessible(true);
    }

    @Test
    @Description("Test if splitting a line in the CSV file works properly")
    public void testSplitLine() throws Exception {
        String line = "1,\"Nuts, pecans\",100 g,691,72g";
        List<String> expected = List.of("1", "Nuts, pecans", "100 g", "691", "72g");

        Object actual = splitLine.invoke(underTest, line, ',');

        assertEquals(expected, actual);
    }

    @Test
    @Description("Tests, if the columns to be extracted are found in the correct place and assigned with the correct index")
    public void testGetColumnIndexes() throws Exception {
        String header = ",name,calories,total_fat,saturated_fat,cholesterol,sodium";
        String[] extract = new String[]{"name", "sodium"};
        int[] expected = new int[]{1, 6};

        int[] actual = (int[]) getColIdxs.invoke(underTest, header, ',', extract);
        assertArrayEquals(expected, actual);
    }

    @Test
    @Description("Test, if getting a list of ingredients from CSV works")
    public void testGetIngredientsFromCSV() throws Exception {
        String relative = "/data/testdata.csv";
        URL resourceUrl = underTest.getClass().getResource(relative);
        assert resourceUrl != null;
        Path path = Paths.get(resourceUrl.toURI());
        String absolutePath = path.toFile().getAbsolutePath();

        String[] extract = new String[]{"name", "calories", "carbohydrate", "fat", "protein", "fiber", "sodium"};
        List<Ingredient> expected = List.of(new Ingredient(Measurement.GRAM, "Cornstarch", new NutritionTable(381.0, 91.27, 0.05, 0.26, 0.9, 0.009)));
        List<Ingredient> actual = underTest.getIngredientsFromCSV(absolutePath, ',', extract);

        assertEquals(expected, actual);
    }
}