diff --git a/common/src/algorithms/movementDirection.spec.ts b/common/src/algorithms/movementDirection.spec.ts
new file mode 100644
index 0000000..a51dd2b
--- /dev/null
+++ b/common/src/algorithms/movementDirection.spec.ts
@@ -0,0 +1,47 @@
+import { countShips } from "./movementDirection"
+import { expect } from "chai";
+import "mocha";
+
+describe("The countShips function", () => {
+	it("should count the ships correctly when unbalanced", () => {
+		let r = countShips(["p3", null, "p1", "p2", null, "p4"], 2);
+		expect(r).to.have.keys(`left`, `right`);
+		expect(r.left).to.equal(1);
+		expect(r.right).to.equal(2);
+	});
+
+	it("should count the ships correctly when balanced", () => {
+		let r = countShips(["p3", null, "p1", "p2", null], 2);
+		expect(r).to.have.keys(`left`, `right`);
+		expect(r.left).to.equal(1);
+		expect(r.right).to.equal(1);
+	});
+
+	it("should count the ships correctly when shipLocation is at the start of the array", () => {
+		let r = countShips(["p3", null, "p1", "p2", null], 0);
+		expect(r).to.have.keys(`left`, `right`);
+		expect(r.left).to.equal(0);
+		expect(r.right).to.equal(2);
+	});
+
+	it("should count the ships correctly when shipLocation is at the end of the array", () => {
+		let r = countShips(["p3", null, "p1", "p2", null, "p4"], 5);
+		expect(r).to.have.keys(`left`, `right`);
+		expect(r.left).to.equal(3);
+		expect(r.right).to.equal(0);
+	});
+
+	it("should throw an error when shipLocation is larger than length", () => {
+		try {
+			countShips(["p3", null, "p1", "p2", null, "p4"], 8);
+			throw "Function didn't throw an error";
+		} catch (_) {}
+	});
+
+	it("should throw an error when shipLocation is less than 0", () => {
+		try {
+			countShips(["p3", null, "p1", "p2", null, "p4"], -3);
+			throw "Function didn't throw an error";
+		} catch (_) {}
+	});
+});
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