Improved mem tests

mem/src/test/java/com/ledmington/mem/TestUninitializedMemory.java

@@ -0,0 +1,103 @@
+/*
+ * emu - Processor Emulator
+ * Copyright (C) 2023-2025 Filippo Barbari <[email protected]>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.ledmington.mem;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.Set;
+import java.util.random.RandomGenerator;
+import java.util.random.RandomGeneratorFactory;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public final class TestUninitializedMemory {
+
+	private static final RandomGenerator rng =
+			RandomGeneratorFactory.getDefault().create(System.nanoTime());
+
+	private MemoryController mem;
+
+	@BeforeEach
+	public void setup() {
+		// Creating a memory controller with all permissions on the whole range, but without initialising anything
+		mem = new MemoryController(new RandomAccessMemory(MemoryInitializer.random()), true, true);
+		mem.setPermissions(Long.MIN_VALUE, Long.MAX_VALUE, true, true, true);
+	}
+
+	@Test
+	void cannotRead() {
+		final Set<Long> positions =
+				Stream.generate(rng::nextLong).distinct().limit(100).collect(Collectors.toSet());
+
+		for (final long address : positions) {
+			assertThrows(MemoryException.class, () -> mem.read(address));
+		}
+	}
+
+	@Test
+	void canReadAfterInitialization() {
+		final Set<Long> positions =
+				Stream.generate(rng::nextLong).distinct().limit(100).collect(Collectors.toSet());
+
+		for (final long address : positions) {
+			mem.write(address, 0);
+		}
+
+		for (final long address : positions) {
+			assertDoesNotThrow(() -> mem.read(address));
+		}
+	}
+
+	@Test
+	void cannotExecute() {
+		final Set<Long> positions =
+				Stream.generate(rng::nextLong).distinct().limit(100).collect(Collectors.toSet());
+
+		for (final long address : positions) {
+			assertThrows(MemoryException.class, () -> mem.readCode(address));
+		}
+	}
+
+	@Test
+	void canExecuteAfterInitialization() {
+		final Set<Long> positions =
+				Stream.generate(rng::nextLong).distinct().limit(100).collect(Collectors.toSet());
+
+		for (final long address : positions) {
+			mem.write(address, 0);
+		}
+
+		for (final long address : positions) {
+			assertDoesNotThrow(() -> mem.readCode(address));
+		}
+	}
+
+	@Test
+	void canWrite() {
+		final Set<Long> positions =
+				Stream.generate(rng::nextLong).distinct().limit(100).collect(Collectors.toSet());
+
+		for (final long address : positions) {
+			assertDoesNotThrow(() -> mem.write(address, 0));
+		}
+	}
+}