--- a/spec/util_ringbuffer_spec.lua	Tue May 19 19:27:43 2026 +0100
+++ b/spec/util_ringbuffer_spec.lua	Mon May 25 19:01:23 2026 +0100
@@ -35,6 +35,51 @@
 		end);
 	end);
 
+	describe(":find", function ()
+		local function test_find(b, str, expected)
+			if expected ~= nil then
+				assert.equal(expected, b:find(str));
+			else
+				assert.is_nil(b:find(str));
+			end
+		end
+
+		it("works", function ()
+			local b = rb.new();
+			assert.truthy(b:write("hello world"));
+			test_find(b, "world", 7);
+		end);
+
+		it("works across wraps", function ()
+			local b = rb.new(5);
+			assert.truthy(b:write("12345"));
+			assert.equal("123", b:read(3));
+			assert.truthy(b:write("678"));
+			test_find(b, "45678", 1);
+			test_find(b, "567", 2);
+			test_find(b, "56", 2);
+			test_find(b, "5", 2);
+			test_find(b, "6", 3);
+			test_find(b, "7", 4);
+			test_find(b, "8", 5);
+			test_find(b, "9", nil);
+		end);
+
+		it("no match when the needle is larger than the buffer", function ()
+			for i = 5, 11 do
+				local b = rb.new(i);
+				assert.truthy(b:write("hello"));
+				test_find(b, "hello world", nil);
+			end
+		end);
+
+		it("no match when the needle is an empty string", function ()
+			local b = rb.new(5);
+			assert.truthy(b:write("hello"));
+			test_find(b, "", nil);
+		end);
+	end);
+
 	describe(":sub", function ()
 		-- Helper function to compare buffer:sub() with string:sub()
 		local function test_sub(b, x, y)