util.sasl: Add stub tests

Random uncommitted file I found when cleaning out my work dir

spec/util_sasl_spec.lua

@@ -0,0 +1,43 @@
+local sasl = require "util.sasl";
+
+-- profile * mechanism
+-- callbacks could use spies instead
+
+describe("util.sasl", function ()
+	describe("plain_test profile", function ()
+		local profile = {
+			plain_test = function (_, username, password, realm)
+				assert.equals("user", username)
+				assert.equals("pencil", password)
+				assert.equals("sasl.test", realm)
+				return true, true;
+			end;
+		};
+		it("works with PLAIN", function ()
+			local plain = sasl.new("sasl.test", profile);
+			assert.truthy(plain:select("PLAIN"));
+			assert.truthy(plain:process("\000user\000pencil"));
+			assert.equals("user", plain.username);
+		end);
+	end);
+
+	describe("plain profile", function ()
+		local profile = {
+			plain = function (_, username, realm)
+				assert.equals("user", username)
+				assert.equals("sasl.test", realm)
+				return "pencil", true;
+			end;
+		};
+
+		it("works with PLAIN", function ()
+			local plain = sasl.new("sasl.test", profile);
+			assert.truthy(plain:select("PLAIN"));
+			assert.truthy(plain:process("\000user\000pencil"));
+			assert.equals("user", plain.username);
+		end);
+
+		-- TODO SCRAM
+	end);
+end);
+