Test a Flow component alone with Flow.test()

Total.js 5 · total5@0.0.19 flowflowstreamcomponentstests Executed against Total.js 5

Flow.test(name, source, [config], [init]) builds a flow with one component (the source is its code, like in the recipe of FlowStream, and config replaces its configuration) and a dummy component that collects its outputs. init(test) is called when the flow is ready, with the object test:

test.send(inputid, data) (also test.input) sends a message to an input of the component and returns it.
test.message = function($, data): called with every message that the component sends to any of its outputs; $ is the message and data its data.
test.reconfigure(config) changes the configuration; test.configure = function(config) is called after it. test.variables(object) sets the variables of the flow.
test.assert(ok, message), test.ok(message) and test.fail(message) print [OK] or [NO] with the date, and a failure throws. The functions are plain properties: replace test.ok and test.fail to send the result somewhere else, as the example does.
The test flow always has the id test: only one Flow.test() at a time.

It is meant for the tests of a component that is written for a Flow, run with node index.js in a small application of its own.

definitions/component-test.js

MAIN.results = [];

const source = `<script total>
exports.id = 'tax';
exports.name = 'Tax';
exports.inputs = [{ id: 'input', name: 'Input' }];
exports.outputs = [{ id: 'output', name: 'Output' }];
exports.config = { rate: 21 };
exports.make = function(instance, config) {
	instance.message = function($) {
		$.send('output', { net: $.data, total: Math.round($.data * (100 + config.rate)) / 100 });
	};
};
</script>`;

ON('ready', function() {
	Flow.test('tax', source, { rate: 10 }, function(test) {

		test.ok = message => MAIN.results.push('ok: ' + message);
		test.fail = message => MAIN.results.push('no: ' + message);

		test.message = function($, data) {
			test.assert(data.net === 100, 'the net amount comes back');
			test.assert(data.total === 110, 'the configuration of the test (10 %) is used, got ' + data.total);
			MAIN.results.push('message: ' + JSON.stringify(data));
		};

		test.send('input', 100);
	});
});

controllers/results.js

exports.install = function() {
	ROUTE('GET /results/', results);
};

function results($) {
	$.json(MAIN.results);
}