Add tests, remove main in LinearSearchThread (#5671)

src/test/java/com/thealgorithms/searches/LinearSearchThreadTest.java

@@ -0,0 +1,74 @@
+package com.thealgorithms.searches;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class LinearSearchThreadTest {
+
+    /**
+     * Test for finding an element that is present in the array.
+     */
+    @Test
+    void testSearcherFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, array.length, 5);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The element 5 should be found in the array.");
+    }
+
+    /**
+     * Test for finding an element that is not present in the array.
+     */
+    @Test
+    void testSearcherNotFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, array.length, 11);
+        searcher.start();
+        searcher.join();
+        assertFalse(searcher.getResult(), "The element 11 should not be found in the array.");
+    }
+
+    /**
+     * Test for searching a segment of the array.
+     */
+    @Test
+    void testSearcherSegmentFound() throws InterruptedException {
+        int[] array = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+        Searcher searcher = new Searcher(array, 0, 5, 3);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The element 3 should be found in the segment.");
+    }
+
+    /**
+     * Test for searching an empty array segment.
+     */
+    @Test
+    void testSearcherEmptySegment() throws InterruptedException {
+        int[] array = {};
+        Searcher searcher = new Searcher(array, 0, 0, 1); // Empty array
+        searcher.start();
+        searcher.join();
+        assertFalse(searcher.getResult(), "The element should not be found in an empty segment.");
+    }
+
+    /**
+     * Test for searching with random numbers.
+     */
+    @Test
+    void testSearcherRandomNumbers() throws InterruptedException {
+        int size = 200;
+        int[] array = new int[size];
+        for (int i = 0; i < size; i++) {
+            array[i] = (int) (Math.random() * 100);
+        }
+        int target = array[(int) (Math.random() * size)]; // Randomly select a target that is present
+        Searcher searcher = new Searcher(array, 0, size, target);
+        searcher.start();
+        searcher.join();
+        assertTrue(searcher.getResult(), "The randomly selected target should be found in the array.");
+    }
+}