Add tests for CheckGuess and ReadVersionFile to verify fixes

Co-authored-by: Project516 <138796702+Project516@users.noreply.github.com>

Author: Copilot

app/src/test/java/io/github/project516/NumberGuessingGame/CheckGuessTest.java

@@ -0,0 +1,50 @@
+package io.github.project516.NumberGuessingGame;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class CheckGuessTest {
+    @Test
+    void quitAcceptsZero() {
+        CheckGuess check = new CheckGuess();
+        assertDoesNotThrow(() -> check.quit(0), "quit should accept 0");
+    }
+
+    @Test
+    void quitAcceptsOne() {
+        CheckGuess check = new CheckGuess();
+        assertDoesNotThrow(() -> check.quit(1), "quit should accept 1");
+    }
+
+    @Test
+    void quitRejectsOtherNumbers() {
+        CheckGuess check = new CheckGuess();
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> check.quit(2),
+                "quit should reject numbers other than 0 or 1");
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> check.quit(-1),
+                "quit should reject numbers other than 0 or 1");
+    }
+
+    @Test
+    void checkAcceptsValidGuess() {
+        CheckGuess check = new CheckGuess();
+        assertDoesNotThrow(() -> check.check(50), "check should accept valid guess");
+        assertDoesNotThrow(() -> check.check(1), "check should accept 1");
+        assertDoesNotThrow(() -> check.check(100), "check should accept 100");
+    }
+
+    @Test
+    void checkRejectsInvalidGuess() {
+        CheckGuess check = new CheckGuess();
+        assertThrows(IllegalArgumentException.class, () -> check.check(0), "check should reject 0");
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> check.check(102),
+                "check should reject numbers > 101");
+    }
+}

app/src/test/java/io/github/project516/NumberGuessingGame/ReadVersionFileTest.java

@@ -0,0 +1,22 @@
+package io.github.project516.NumberGuessingGame;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class ReadVersionFileTest {
+    @Test
+    void readVersionReturnsNonEmptyString() {
+        ReadVersionFile versionFile = new ReadVersionFile();
+        String version = versionFile.readVersion();
+        assertNotNull(version, "Version should not be null");
+        assertFalse(version.isEmpty(), "Version should not be empty");
+    }
+
+    @Test
+    void readVersionReturnsRolling() {
+        ReadVersionFile versionFile = new ReadVersionFile();
+        String version = versionFile.readVersion();
+        assertEquals("rolling", version, "Version should be 'rolling'");
+    }
+}