diff --git a/Manifest.toml b/Manifest.toml
index 25749f9b39f60fd4d2c6754e46a6928d4601ad76..c4dde87ac3ac5c03582d26235494e2b26382fa1d 100644
--- a/Manifest.toml
+++ b/Manifest.toml
@@ -2,7 +2,7 @@
 
 julia_version = "1.9.3"
 manifest_format = "2.0"
-project_hash = "e0c77beb18dc1f6cce661ebd60658c0c1a77390f"
+project_hash = "cde703bfa3f648aa63354f4e861d6be54804f556"
 
 [[deps.ANSIColoredPrinters]]
 git-tree-sha1 = "574baf8110975760d391c710b6341da1afa48d8c"
diff --git a/Project.toml b/Project.toml
index 610bcd6b5999eebf82289a2408d143d18b5b375a..00404814f58588930ec1c5a836e44db897bcf193 100644
--- a/Project.toml
+++ b/Project.toml
@@ -5,3 +5,4 @@ version = "0.1.0"
 
 [deps]
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
diff --git a/test/runtests.jl b/test/runtests.jl
new file mode 100644
index 0000000000000000000000000000000000000000..8a8da45909684709f3151ea4473256054b233983
--- /dev/null
+++ b/test/runtests.jl
@@ -0,0 +1 @@
+include("test_add.jl")
diff --git a/test/test_add.jl b/test/test_add.jl
new file mode 100644
index 0000000000000000000000000000000000000000..788df9e307f8a984e760fae66a45d41ac20a9bc7
--- /dev/null
+++ b/test/test_add.jl
@@ -0,0 +1,9 @@
+using SustainableSoftwareEngineering
+using Test
+
+@testset "Addition Tests" begin
+    @test add(2, 2) == 4
+    @test add(-1, 1) == 0
+    @test add(0, 0) == 0
+    @test_throws MethodError add("a", "b")
+end