diff --git a/docs/README.md b/docs/README.md
new file mode 100644
index 00000000..6a2a10a3
--- /dev/null
+++ b/docs/README.md
@@ -0,0 +1,50 @@
+# 💪 프로젝트 개요
+
+숫자 야구 게임
+
+# 게임 설명
+
+- 기본적으로 1부터 9까지 서로 다른 수로 이루어진 3자리의 수를 맞추는 게임이다.
+- 같은 수가 같은 자리에 있으면 스트라이크, 다른 자리에 있으면 볼, 같은 수가 전혀 없으면 포볼 또는 낫싱이란 힌트를
+얻고, 그 힌트를 이용해서 먼저 상대방(컴퓨터)의 수를 맞추면 승리한다.
+- [예] 상대방(컴퓨터)의 수가 425일 때, 123을 제시한 경우 : 1스트라이크, 456을 제시한 경우 : 1스트라이크 1볼,
+789를 제시한 경우 : 낫싱
+- 위 숫자 야구게임에서 상대방의 역할을 컴퓨터가 한다. 컴퓨터는 1에서 9까지 서로 다른 임의의 수 3개를 선택한다. 게
+임 플레이어는 컴퓨터가 생각하고 있는 3개의 숫자를 입력하고, 컴퓨터는 입력한 숫자에 대한 결과를 출력한다.
+- 이 같은 과정을 반복해 컴퓨터가 선택한 3개의 숫자를 모두 맞히면 게임이 종료된다.
+- 게임을 종료한 후 게임을 다시 시작하거나 완전히 종료할 수 있다.
+- 사용자가 잘못된 값을 입력할 경우 [ERROR]로 시작하는 에러 메시지를 출력하고 게임을 계속 진행할 수 있어야 한다.
+
+# 📝 구현 기능 목록
+
+### 게임 준비 기능
+- [x] 컴퓨터는 1에서 9까지 서로 다른 임의의 수 3개를 선택하고 저장한다.
+
+### 사용자 입력 기능
+- [x] `숫자를 입력해주세요 :`를 출력한다.
+- [x] 사용자에게 입력을 받는다.
+- [x] 입력값을 검증한다.
+  - [x] 빈 문자열이나 공백이면 에러를 반환한다.
+  - [x] 입력된 문자열의 길이가 3이 아니면 에러를 반환한다.
+  - [x] 3개 중에 하나라도 숫자가 아니면 에러를 반환한다. 
+  - [x] 숫자에 0이 포함되어 있으면 에러를 반환한다.
+  - [x] 서로 다른 숫자가 아니면 에러를 반환한다.
+  - [x] 에러를 반환한 경우에는 에러 메시지를 출력한 후에 입력을 다시 받는다.
+
+### 게임 기능
+- [x] 결과를 판단한다.
+  - [x] 스트라이크와 볼 갯수를 센다.
+    - [x] 같은 수가 같은 자리에 있으면 스트라이크를 추가한다.
+    - [x] 같은 수가 다른 자리에 있으면 볼을 추가한다.
+  - [x] 스트라이크와 볼이 없으면 낫싱으로 판단한다.
+- [x] 결과를 출력한다.
+- [x] 정답이 아니면 `숫자를 입력해주세요 :`를 출력하고 사용자에게 다시 입력을 받는다.
+
+### 게임 종료 기능
+- [x] `3개의 숫자를 모두 맞히셨습니다! 게임 끝`를 출력하고 종료한다.
+- [x] `게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.`를 출력한다.
+- [x] 사용자에게 1 또는 2를 입력받는다.
+- [x] 다른 값인 경우에는 에러를 반환한다.
+  - [x] 에러를 반환한 경우에는 에러 메시지를 출력한 후에 입력을 다시 받는다.
+- [x] 1을 입력받은 경우 게임 준비 기능부터 게임을 새로 시작한다.
+- [x] 2를 입력받은 경우 게임을 종료한다.
diff --git a/src/main/java/.gitkeep b/src/main/java/.gitkeep
deleted file mode 100644
index e69de29b..00000000
diff --git a/src/main/java/baseball/Application.java b/src/main/java/baseball/Application.java
new file mode 100644
index 00000000..5287d248
--- /dev/null
+++ b/src/main/java/baseball/Application.java
@@ -0,0 +1,15 @@
+package baseball;
+
+import baseball.controller.BaseballController;
+import baseball.view.InputView;
+import baseball.view.OutputView;
+
+public class Application {
+    public static void main(String[] args) {
+        BaseballController baseballController = new BaseballController(
+                new InputView(),
+                new OutputView()
+        );
+        baseballController.run();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/baseball/controller/BaseballController.java b/src/main/java/baseball/controller/BaseballController.java
new file mode 100644
index 00000000..e0312d6f
--- /dev/null
+++ b/src/main/java/baseball/controller/BaseballController.java
@@ -0,0 +1,50 @@
+package baseball.controller;
+
+import baseball.domain.ComputerNumbers;
+import baseball.domain.Numbers;
+import baseball.domain.Result;
+import baseball.domain.ResultType;
+import baseball.global.exception.CustomException;
+import baseball.global.message.InputMessage;
+import baseball.view.InputView;
+import baseball.view.OutputView;
+
+public class BaseballController {
+    private final InputView inputView;
+    private final OutputView outputView;
+
+    public BaseballController(InputView inputView, OutputView outputView) {
+        this.inputView = inputView;
+        this.outputView = outputView;
+    }
+
+    public void run() {
+        ComputerNumbers computerNumbers = new ComputerNumbers();
+        process(computerNumbers);
+    }
+
+    public void process(ComputerNumbers computerNumbers) {
+        Numbers inputNumbers = requestNumbers();
+        Result result = new Result(computerNumbers, inputNumbers);
+        outputView.printlnStrikeAndBall(result);
+        if (result.getResultType() != ResultType.THREE_STRIKE) {
+            process(computerNumbers);
+            return;
+        }
+        outputView.printlnThreeStrike();
+        if (inputView.enterFinishType() == 1) {
+            run();
+        }
+    }
+
+    private Numbers requestNumbers() {
+        outputView.printMessage(InputMessage.INPUT_NUMBERS.getMessage());
+        try {
+            Numbers numbers = new Numbers(inputView.enterNumbers());
+            return numbers;
+        } catch (CustomException e) {
+            outputView.printlnMessage(e.getMessage());
+            return requestNumbers();
+        }
+    }
+}
diff --git a/src/main/java/baseball/domain/ComputerNumbers.java b/src/main/java/baseball/domain/ComputerNumbers.java
new file mode 100644
index 00000000..f9b37026
--- /dev/null
+++ b/src/main/java/baseball/domain/ComputerNumbers.java
@@ -0,0 +1,32 @@
+package baseball.domain;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class ComputerNumbers {
+    private final Numbers numbers;
+
+    public ComputerNumbers() {
+        int[] randomNumbers = generateRandomNumbers();
+        this.numbers = new Numbers(randomNumbers);
+    }
+
+    private int[] generateRandomNumbers() {
+        List<Integer> allNumbers = new ArrayList<>();
+        for (int i = 1; i <= 9; i++) {
+            allNumbers.add(i);
+        }
+        Collections.shuffle(allNumbers);
+        int[] result = {allNumbers.get(0), allNumbers.get(1), allNumbers.get(2)};
+        return result;
+    }
+
+    public Number get(int idx) {
+        return numbers.get(idx);
+    }
+
+    public boolean notContain(Number number) {
+        return numbers.notContain(number);
+    }
+}
diff --git a/src/main/java/baseball/domain/Number.java b/src/main/java/baseball/domain/Number.java
new file mode 100644
index 00000000..3c90f774
--- /dev/null
+++ b/src/main/java/baseball/domain/Number.java
@@ -0,0 +1,13 @@
+package baseball.domain;
+
+public class Number {
+    private final int num;
+
+    public Number(int num) {
+        this.num = num;
+    }
+
+    public boolean isSameValue(Number number) {
+        return this.num == number.num;
+    }
+}
diff --git a/src/main/java/baseball/domain/Numbers.java b/src/main/java/baseball/domain/Numbers.java
new file mode 100644
index 00000000..219a7078
--- /dev/null
+++ b/src/main/java/baseball/domain/Numbers.java
@@ -0,0 +1,32 @@
+package baseball.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Numbers {
+    private final List<Number> numbers;
+
+    public Numbers(int[] arr) {
+        numbers = new ArrayList<>();
+        for (int num : arr) {
+            numbers.add(new Number(num));
+        }
+    }
+
+    public Number get(int idx) {
+        return numbers.get(idx);
+    }
+
+    public boolean notContain(Number inputNumber) {
+        for (Number number: numbers) {
+            if (number.isSameValue(inputNumber)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public int size() {
+        return numbers.size();
+    }
+}
diff --git a/src/main/java/baseball/domain/Result.java b/src/main/java/baseball/domain/Result.java
new file mode 100644
index 00000000..5c47a248
--- /dev/null
+++ b/src/main/java/baseball/domain/Result.java
@@ -0,0 +1,39 @@
+package baseball.domain;
+
+public class Result {
+
+    private final ResultType resultType;
+    private final int strike;
+    private final int ball;
+
+    public Result(ComputerNumbers computerNumbers, Numbers inputNumbers) {
+        int strike = 0;
+        int ball = 0;
+        for (int idx = 0; idx < inputNumbers.size(); idx++) {
+            Number number = inputNumbers.get(idx);
+            if (computerNumbers.notContain(number)) {
+                continue;
+            }
+            if (number.isSameValue(computerNumbers.get(idx))) {
+                strike++;
+                continue;
+            }
+            ball++;
+        }
+        this.strike = strike;
+        this.ball = ball;
+        this.resultType = ResultType.getResult(strike, ball);
+    }
+
+    public ResultType getResultType() {
+        return resultType;
+    }
+
+    public int getStrike() {
+        return strike;
+    }
+
+    public int getBall() {
+        return ball;
+    }
+}
diff --git a/src/main/java/baseball/domain/ResultType.java b/src/main/java/baseball/domain/ResultType.java
new file mode 100644
index 00000000..f58c2a45
--- /dev/null
+++ b/src/main/java/baseball/domain/ResultType.java
@@ -0,0 +1,18 @@
+package baseball.domain;
+
+public enum ResultType {
+    THREE_STRIKE,
+    STRIKE_AND_BALL,
+    NOTHING
+    ;
+
+    public static ResultType getResult(int strike, int ball) {
+        if (strike == 3) {
+            return THREE_STRIKE;
+        }
+        if (strike != 0 || ball != 0) {
+            return STRIKE_AND_BALL;
+        }
+        return NOTHING;
+    }
+}
diff --git a/src/main/java/baseball/global/exception/CustomException.java b/src/main/java/baseball/global/exception/CustomException.java
new file mode 100644
index 00000000..8fd4dfd1
--- /dev/null
+++ b/src/main/java/baseball/global/exception/CustomException.java
@@ -0,0 +1,13 @@
+package baseball.global.exception;
+
+import baseball.global.message.ErrorMessage;
+
+public class CustomException extends IllegalArgumentException {
+    private CustomException(ErrorMessage errorMessage) {
+        super(errorMessage.getMessage());
+    }
+
+    public static CustomException of(ErrorMessage errorMessage) {
+        return new CustomException(errorMessage);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/baseball/global/message/ErrorMessage.java b/src/main/java/baseball/global/message/ErrorMessage.java
new file mode 100644
index 00000000..43dcb3a2
--- /dev/null
+++ b/src/main/java/baseball/global/message/ErrorMessage.java
@@ -0,0 +1,22 @@
+package baseball.global.message;
+
+public enum ErrorMessage {
+    BLANK_INPUT("빈 문자열이 입력되었습니다."),
+    INVALID_INPUT_LENGTH("3개를 입력해주세요"),
+    NON_DIGIT_CHARACTER_FOUND("모두 숫자로 입력해주세요"),
+    NON_POSITIVE_NUMBER_FOUND("모두 0보다 큰 양수로 입력해주세요."),
+    DUPLICATE_NUMBER_FOUND("서로 다른 숫자로 입력해주세요."),
+    INVALID_FINISH_INPUT("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.")
+    ;
+
+    private final static String PREFIX = "[ERROR]";
+    private final String message;
+
+    ErrorMessage(String message) {
+        this.message = message;
+    }
+
+    public String getMessage() {
+        return PREFIX + " " + this.message;
+    }
+}
diff --git a/src/main/java/baseball/global/message/InputMessage.java b/src/main/java/baseball/global/message/InputMessage.java
new file mode 100644
index 00000000..fd41ed23
--- /dev/null
+++ b/src/main/java/baseball/global/message/InputMessage.java
@@ -0,0 +1,17 @@
+package baseball.global.message;
+
+public enum InputMessage {
+
+    INPUT_NUMBERS("숫자를 입력해주세요 : ")
+    ;
+
+    private String message;
+
+    InputMessage(String message) {
+        this.message = message;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+}
diff --git a/src/main/java/baseball/view/InputView.java b/src/main/java/baseball/view/InputView.java
new file mode 100644
index 00000000..a76a6c69
--- /dev/null
+++ b/src/main/java/baseball/view/InputView.java
@@ -0,0 +1,85 @@
+package baseball.view;
+
+import baseball.global.exception.CustomException;
+import baseball.global.message.ErrorMessage;
+
+import java.util.Scanner;
+
+public class InputView {
+
+    public int[] enterNumbers() {
+        String input = readLine();
+        validateStringFormat(input);
+        int[] nums = validateNumberFormat(input);
+        return nums;
+    }
+
+    public int enterFinishType() {
+        String input = readLine();
+        int num = parseFinishType(input);
+        return num;
+    }
+
+    private int parseFinishType(String input) {
+        if (input.length() != 1 || !Character.isDigit(input.charAt(0))) {
+            throw CustomException.of(ErrorMessage.INVALID_FINISH_INPUT);
+        }
+        int num = input.charAt(0) - '0';
+        if (num != 1 && num != 2) {
+            throw CustomException.of(ErrorMessage.INVALID_FINISH_INPUT);
+        }
+        return num;
+    }
+
+    private void validateStringFormat(String str) {
+        if (isEmptyOrBlank(str)) {
+            throw CustomException.of(ErrorMessage.BLANK_INPUT);
+        }
+        if (str.length() != 3) {
+            throw CustomException.of(ErrorMessage.INVALID_INPUT_LENGTH);
+        }
+    }
+
+    private int[] validateNumberFormat(String str) {
+        int[] nums = new int[3];
+        for (int i = 0; i < 3; i++) {
+            validateDigit(str.charAt(i));
+            int num = str.charAt(i) - '0';
+            validatePositiveNumber(num);
+            nums[i] = num;
+        }
+        validateDuplicate(nums);
+        return nums;
+    }
+
+    private void validateDigit(char c) {
+        if (!Character.isDigit(c)) {
+            throw CustomException.of(ErrorMessage.NON_DIGIT_CHARACTER_FOUND);
+        }
+    }
+
+    private void validatePositiveNumber(int num) {
+        if (num <= 0) {
+            throw CustomException.of(ErrorMessage.NON_POSITIVE_NUMBER_FOUND);
+        }
+    }
+
+    private void validateDuplicate(int[] arr) {
+        if (hasDuplicate(arr)) {
+            throw CustomException.of(ErrorMessage.DUPLICATE_NUMBER_FOUND);
+        }
+    }
+
+    private boolean isEmptyOrBlank(String str) {
+        return str == null || str.isBlank();
+    }
+
+    private static boolean hasDuplicate(int[] arr) {
+        return arr[0] == arr[1] || arr[0] == arr[2] || arr[1] == arr[2];
+    }
+
+    private String readLine() {
+        Scanner scanner = new Scanner(System.in);
+        return scanner.nextLine();
+    }
+}
diff --git a/src/main/java/baseball/view/OutputView.java b/src/main/java/baseball/view/OutputView.java
new file mode 100644
index 00000000..54c46f4e
--- /dev/null
+++ b/src/main/java/baseball/view/OutputView.java
@@ -0,0 +1,54 @@
+package baseball.view;
+
+import baseball.domain.Result;
+import baseball.domain.ResultType;
+
+public class OutputView {
+    public void printlnMessage(String message) {
+        System.out.println(message);
+    }
+
+    public void printMessage(String message) {
+        System.out.print(message);
+    }
+
+    public void printEmptyLine() {
+        System.out.println();
+    }
+
+    public void printlnMessageWithEmptyLine(String message) {
+        printlnMessage(message);
+        printEmptyLine();
+    }
+
+    public void printlnStrikeAndBall(Result result) {
+        if (result.getResultType() == ResultType.NOTHING) {
+            printlnMessage("낫싱");
+            return;
+        }
+        StringBuilder sb = new StringBuilder();
+        appendStrike(result.getStrike(), sb);
+        appendBall(result.getBall(), sb);
+        printlnMessage(sb.toString());
+    }
+
+    public void printlnThreeStrike() {
+        printlnMessage("3개의 숫자를 모두 맞히셨습니다! 게임 끝");
+        printlnMessage("게임을 새로 시작하려면 1, 종료하려면 2를 입력하세요.");
+    }
+
+    private void appendStrike(int strike, StringBuilder sb) {
+        if (strike != 0) {
+            sb.append(strike).append("스트라이크");
+        }
+    }
+
+    private void appendBall(int ball, StringBuilder sb) {
+        if (ball != 0) {
+            if (!sb.isEmpty()) {
+                sb.append(" ");
+            }
+            sb.append(ball).append("볼");
+        }
+    }
+}
diff --git a/src/test/java/baseball/domain/ComputerNumbersTest.java b/src/test/java/baseball/domain/ComputerNumbersTest.java
new file mode 100644
index 00000000..e0c528c4
--- /dev/null
+++ b/src/test/java/baseball/domain/ComputerNumbersTest.java
@@ -0,0 +1,27 @@
+package baseball.domain;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class ComputerNumbersTest {
+
+    @Test
+    void notContain_returnsFalse_forExistingNumberInstance() {
+        ComputerNumbers computerNumbers = new ComputerNumbers();
+
+        Number existingNumber = computerNumbers.get(0);
+
+        assertThat(computerNumbers.notContain(existingNumber)).isFalse();
+    }
+
+    @Test
+    void get_throwsIndexOutOfBounds_whenIndexIsInvalid() {
+        ComputerNumbers computerNumbers = new ComputerNumbers();
+
+        assertThatThrownBy(() -> computerNumbers.get(3))
+                .isInstanceOf(IndexOutOfBoundsException.class)
+                .hasMessageMatching("Index[: ]\\d+.*(Size|length)[: ]\\d+");
+    }
+}
diff --git a/src/test/java/baseball/domain/NumberTest.java b/src/test/java/baseball/domain/NumberTest.java
new file mode 100644
index 00000000..077a5bd7
--- /dev/null
+++ b/src/test/java/baseball/domain/NumberTest.java
@@ -0,0 +1,24 @@
+package baseball.domain;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class NumberTest {
+
+    @Test
+    void isSameValue_returnsTrue_whenValuesMatch() {
+        Number number = new Number(5);
+        Number sameValue = new Number(5);
+
+        assertThat(number.isSameValue(sameValue)).isTrue();
+    }
+
+    @Test
+    void isSameValue_returnsFalse_whenValuesDoNotMatch() {
+        Number number = new Number(5);
+        Number differentValue = new Number(7);
+
+        assertThat(number.isSameValue(differentValue)).isFalse();
+    }
+}
diff --git a/src/test/java/baseball/domain/NumbersTest.java b/src/test/java/baseball/domain/NumbersTest.java
new file mode 100644
index 00000000..9c1d2bae
--- /dev/null
+++ b/src/test/java/baseball/domain/NumbersTest.java
@@ -0,0 +1,48 @@
+package baseball.domain;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+class NumbersTest {
+
+    @Test
+    void size_returnsLengthOfInputArray() {
+        Numbers numbers = new Numbers(new int[]{1, 2, 3});
+
+        assertThat(numbers.size()).isEqualTo(3);
+    }
+
+    @Test
+    void get_returnsNumberAtIndex() {
+        Numbers numbers = new Numbers(new int[]{1, 2, 3});
+
+        Number number = numbers.get(0);
+
+        assertThat(number.isSameValue(new Number(1))).isTrue();
+    }
+
+    @Test
+    void notContain_returnsFalse_whenNumberExists() {
+        Numbers numbers = new Numbers(new int[]{1, 2, 3});
+
+        assertThat(numbers.notContain(new Number(2))).isFalse();
+    }
+
+    @Test
+    void notContain_returnsTrue_whenNumberDoesNotExist() {
+        Numbers numbers = new Numbers(new int[]{1, 2, 3});
+
+        assertThat(numbers.notContain(new Number(9))).isTrue();
+    }
+
+    @Test
+    void get_throwsIndexOutOfBounds_whenIndexIsInvalid() {
+        Numbers numbers = new Numbers(new int[]{1, 2});
+
+        assertThatExceptionOfType(IndexOutOfBoundsException.class)
+                .isThrownBy(() -> numbers.get(2))
+                .withMessageMatching("Index[: ]\\d+.*(Size|length)[: ]\\d+");
+    }
+}
diff --git a/src/test/java/baseball/domain/ResultTest.java b/src/test/java/baseball/domain/ResultTest.java
new file mode 100644
index 00000000..e268cd33
--- /dev/null
+++ b/src/test/java/baseball/domain/ResultTest.java
@@ -0,0 +1,59 @@
+package baseball.domain;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ResultTest {
+
+    private ComputerNumbers fixedComputerNumbers(int[] values) {
+        Numbers numbers = new Numbers(values);
+        return new ComputerNumbers() {
+            @Override
+            public Number get(int idx) {
+                return numbers.get(idx);
+            }
+
+            @Override
+            public boolean notContain(Number number) {
+                return numbers.notContain(number);
+            }
+        };
+    }
+
+    @Test
+    void result_countsThreeStrike_whenAllMatchInPosition() {
+        ComputerNumbers computerNumbers = fixedComputerNumbers(new int[]{1, 2, 3});
+        Numbers inputNumbers = new Numbers(new int[]{1, 2, 3});
+
+        Result result = new Result(computerNumbers, inputNumbers);
+
+        assertThat(result.getStrike()).isEqualTo(3);
+        assertThat(result.getBall()).isEqualTo(0);
+        assertThat(result.getResultType()).isEqualTo(ResultType.THREE_STRIKE);
+    }
+
+    @Test
+    void result_countsStrikeAndBall_whenValuesMatchDifferentPositions() {
+        ComputerNumbers computerNumbers = fixedComputerNumbers(new int[]{1, 2, 3});
+        Numbers inputNumbers = new Numbers(new int[]{1, 3, 2});
+
+        Result result = new Result(computerNumbers, inputNumbers);
+
+        assertThat(result.getStrike()).isEqualTo(1);
+        assertThat(result.getBall()).isEqualTo(2);
+        assertThat(result.getResultType()).isEqualTo(ResultType.STRIKE_AND_BALL);
+    }
+
+    @Test
+    void result_countsNothing_whenNoValuesMatch() {
+        ComputerNumbers computerNumbers = fixedComputerNumbers(new int[]{1, 2, 3});
+        Numbers inputNumbers = new Numbers(new int[]{4, 5, 6});
+
+        Result result = new Result(computerNumbers, inputNumbers);
+
+        assertThat(result.getStrike()).isEqualTo(0);
+        assertThat(result.getBall()).isEqualTo(0);
+        assertThat(result.getResultType()).isEqualTo(ResultType.NOTHING);
+    }
+}
diff --git a/src/test/java/baseball/domain/ResultTypeTest.java b/src/test/java/baseball/domain/ResultTypeTest.java
new file mode 100644
index 00000000..1128f8a9
--- /dev/null
+++ b/src/test/java/baseball/domain/ResultTypeTest.java
@@ -0,0 +1,30 @@
+package baseball.domain;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ResultTypeTest {
+
+    @Test
+    void getResult_returnsThreeStrike_whenStrikeIsThree() {
+        ResultType result = ResultType.getResult(3, 0);
+
+        assertEquals(ResultType.THREE_STRIKE, result);
+        assertThat(result).isEqualTo(ResultType.THREE_STRIKE);
+    }
+
+    @Test
+    void getResult_returnsStrikeAndBall_whenAnyStrikeOrBall() {
+        assertThat(ResultType.getResult(1, 0)).isEqualTo(ResultType.STRIKE_AND_BALL);
+        assertThat(ResultType.getResult(0, 2)).isEqualTo(ResultType.STRIKE_AND_BALL);
+    }
+
+    @Test
+    void getResult_returnsNothing_whenNoStrikeAndNoBall() {
+        ResultType result = ResultType.getResult(0, 0);
+
+        assertEquals(ResultType.NOTHING, result);
+    }
+}