You can add more edge cases to ensure comprehensive testing. For example, test scenarios such as summing negative numbers, concatenating empty strings, and comparing values that are null or undefined.

// Edge Case: Adding negative numbers
it("should correctly add negative numbers", function() {
assert.strictEqual(-1 + -1, -2, "-1 + -1 should equal -2");
assert.strictEqual(-10 + 5, -5, "-10 + 5 should equal -5");
});

// Edge Case: Concatenating empty strings
it("should concatenate empty strings correctly", function() {
const str1 = "";
const str2 = "";
assert.strictEqual(str1 + str2, "", "Concatenating two empty strings should result in an empty string");
assert.strictEqual(str1 + "Test", "Test", "Concatenating an empty string with 'Test' should equal 'Test'");
});

// Edge Case: Comparing null and undefined
it("should compare null and undefined correctly", function() {
assert.strictEqual(null, null, "null should be strictly equal to null");
assert.notStrictEqual(null, undefined, "null should not be strictly equal to undefined");
assert.strictEqual(undefined, undefined, "undefined should be strictly equal to undefined");
});