Shorten the plan stack.

[jamestalmage]

Every call to t.plan generates a stack trace. Apparently those stack traces are expensive. This speeds things up by shortening the stack trace.

I am not sure we need more than a depth of 1.

benchmark:

import test from 'ava';

for (var i = 0; i < 10000; i++) {
    test(`test${i}`, t => {
        t.plan(1);
        t.pass();
    });
}

master:

node cli.js test/lots-of-plans.js --verbose  6.16s user 0.58s system 119% cpu 5.647 total

depth 1 (current value in this PR):

node cli.js test/lots-of-plans.js --verbose  2.43s user 0.48s system 142% cpu 2.044 total

depth of 2:

node cli.js test/lots-of-plans.js --verbose  2.66s user 0.42s system 128% cpu 2.392 total

depth of 3:

node cli.js test/lots-of-plans.js --verbose  3.04s user 0.49s system 133% cpu 2.648 total

depth of 4:

node cli.js test/lots-of-plans.js --verbose  3.24s user 0.50s system 131% cpu 2.850 total

[sindresorhus]

Why not just assign it directly to PublicApi.prototype.plan?

[jamestalmage]

Because plan needs to be passed to Error.captureStackTrace

[sindresorhus]

PublicApi.prototype.plan = function plan(ct) {

[jamestalmage]

Yeah - that works.

[jamestalmage]

@sindresorhus Any thoughts on depth? I really think 1 just works.

[sindresorhus]

Yeah, doesn't make sense to have deeper stack trace for this as you only care about where the plan was defined.

[jamestalmage]

Changes made.

[sindresorhus]

👍