CodeRun/src/test/java/quickStart/QuickStartExercise09Test.java - develop - javapractice/JavaPractice

CodeRun/src/test/java/quickStart/QuickStartExercise09Test.java
152 строки4 KB
Кузьма Даждъбогин
TSKJVPRCTC5-15
15 янв 2026, 15:10
15 янв 2026, 15:10e546175
package quickStart;

import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.PrintStream;
import java.nio.charset.StandardCharsets;

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

class QuickStartExercise09Test {

    private final InputStream systemIn = System.in;
    private final PrintStream systemOut = System.out;

    private ByteArrayInputStream testIn;
    private ByteArrayOutputStream testOut;

    @BeforeEach
    void setUp() {
        testOut = new ByteArrayOutputStream();
        System.setOut(new PrintStream(testOut, true, StandardCharsets.UTF_8));
    }

    @AfterEach
    void tearDown() {
        System.setIn(systemIn);
        System.setOut(systemOut);
    }

    void provideInput(String data) {
        testIn = new ByteArrayInputStream(data.getBytes(StandardCharsets.UTF_8));
        System.setIn(testIn);
    }

    String getOutput() {
        return testOut.toString(StandardCharsets.UTF_8).trim();
    }

    @Test
    void method_shouldMultiply2x3And3x2Matrices() throws Exception {
        // Given: A (2x3), B (3x2)
        String input = "2 3 2\n" +
                "1 2 3\n" +
                "4 5 6\n" +
                "7 8\n" +
                "9 10\n" +
                "11 12";

        String expectedOutput = "58 139\n" +
                "64 154";

        provideInput(input);

        // When
        QuickStartExercise09 q = new QuickStartExercise09();
        q.method();

        // Then
        assertEquals(expectedOutput, getOutput());
    }

    @Test
    void method_shouldMultiply1x1Matrices() throws Exception {
        // Given
        String input = "1 1 1\n" +
                "5\n" +
                "3";

        String expectedOutput = "15";

        provideInput(input);

        // When
        QuickStartExercise09 q = new QuickStartExercise09();
        q.method();

        // Then
        assertEquals(expectedOutput, getOutput());
    }

    @Test
    void method_shouldMultiply2x2MatricesAndOutputByColumns() throws Exception {
        // Given: A = [[1,0],[0,1]], B = [[2,3],[4,5]] → C = [[2,3],[4,5]]
        // Output by columns: "2 4\n3 5"
        String input = "2 2 2\n" +
                "1 0\n" +
                "0 1\n" +
                "2 3\n" +
                "4 5";

        String expectedOutput = "2 4\n" +
                "3 5";

        provideInput(input);

        // When
        QuickStartExercise09 q = new QuickStartExercise09();
        q.method();

        // Then
        assertEquals(expectedOutput, getOutput());
    }

    @Test
    void method_shouldHandleIdentityMultiplication() throws Exception {
        // Given: A = [[2,3],[4,5]], B = [[1,0],[0,1]] → C = A
        String input = "2 2 2\n" +
                "2 3\n" +
                "4 5\n" +
                "1 0\n" +
                "0 1";

        String expectedOutput = "2 4\n" +
                "3 5";

        provideInput(input);

        // When
        QuickStartExercise09 q = new QuickStartExercise09();
        q.method();

        // Then
        assertEquals(expectedOutput, getOutput());
    }

    @Test
    void method_shouldHandleZeroMatrixMultiplication() throws Exception {
        // Given: A filled with 0
        String input = "2 2 2\n" +
                "0 0\n" +
                "0 0\n" +
                "1 2\n" +
                "3 4";

        String expectedOutput = "0 0\n" +
                "0 0";

        provideInput(input);

        // When
        QuickStartExercise09 q = new QuickStartExercise09();
        q.method();

        // Then
        assertEquals(expectedOutput, getOutput());
    }
}