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Tape with promise support.


Same as tape, except if you return a promise from a test, it will be checked for errors. If there are no errors, the test will end. Otherwise the test will fail. This means there is no need to use t.plan() or t.end().

Also provides t.shouldFail(promise P, optional class|regex expected, optional message) (as well as the alias shouldReject) which returns a new promise that resolves successfully if P rejects. If you provide the optional class, or regex then it additionally ensures that err is an instance of that class or that the message matches the regular expression. The behaviour is identical to tape's throws assertion.


Assuming delay() returns a promise:

const test = require('blue-tape');
test("simple delay", function(t) {
    return delay(1);
test("should fail", function(t) {
    return delay(1).then(function() {
        throw new Error("Failed!");

Assuming failDelay() returns a promise that rejects with a DerpError:

test("promise fails but test succeeds", function(t) {
    return t.shouldFail(failDelay(), DerpError);