Fix/ref to

[Eomm]

Hi, this PR fixes #136

I run the bench.js three times with Node 10.11.
I don't expect any improvement or defect on overall performance because these changes should be executed only when a $ref = '#customId' is found.

master:

FJS creation x 5,465 ops/sec ±5.09% (84 runs sampled)
JSON.stringify array x 2,375 ops/sec ±1.04% (92 runs sampled)
fast-json-stringify array x 5,698 ops/sec ±2.89% (90 runs sampled)
fast-json-stringify-uglified array x 5,255 ops/sec ±3.61% (84 runs sampled)
JSON.stringify long string x 9,292 ops/sec ±0.73% (91 runs sampled)
fast-json-stringify long string x 9,155 ops/sec ±2.34% (92 runs sampled)
fast-json-stringify-uglified long string x 9,315 ops/sec ±0.30% (95 runs sampled)
JSON.stringify short string x 3,425,224 ops/sec ±6.24% (81 runs sampled)
fast-json-stringify short string x 29,926,884 ops/sec ±1.38% (88 runs sampled)
fast-json-stringify-uglified short string x 29,070,119 ops/sec ±1.53% (87 runs sampled)
JSON.stringify obj x 1,304,634 ops/sec ±1.25% (92 runs sampled)
fast-json-stringify obj x 5,742,953 ops/sec ±1.12% (89 runs sampled)
fast-json-stringify-uglified obj x 5,716,443 ops/sec ±1.03% (91 runs sampled)

this branch:

FJS creation x 5,498 ops/sec ±4.91% (84 runs sampled)
JSON.stringify array x 2,217 ops/sec ±4.27% (86 runs sampled)
fast-json-stringify array x 5,506 ops/sec ±4.50% (85 runs sampled)
fast-json-stringify-uglified array x 5,455 ops/sec ±4.81% (83 runs sampled)
JSON.stringify long string x 9,002 ops/sec ±2.77% (89 runs sampled)
fast-json-stringify long string x 9,312 ops/sec ±0.51% (94 runs sampled)
fast-json-stringify-uglified long string x 9,325 ops/sec ±0.34% (92 runs sampled)
JSON.stringify short string x 3,898,407 ops/sec ±0.98% (92 runs sampled)
fast-json-stringify short string x 28,256,237 ops/sec ±4.10% (82 runs sampled)
fast-json-stringify-uglified short string x 29,507,831 ops/sec ±1.74% (86 runs sampled)
JSON.stringify obj x 1,201,048 ops/sec ±7.02% (82 runs sampled)
fast-json-stringify obj x 5,713,316 ops/sec ±1.04% (88 runs sampled)
fast-json-stringify-uglified obj x 5,601,133 ops/sec ±1.63% (89 runs sampled)

[mcollina]

Would this make it compatitble with fluent-schema?

[mcollina]

Can you put in a couple of comments explaining the if condition?

[Eomm]

Done, let me know if I should add more details

[Eomm]

Would this make it compatitble with fluent-schema?

Yes, generally with this fix, the schema.response.200 settings in fastify will accept the $ref = '#customId attribute without failing (already tried to run this fix in fastify and works, will send a PR with this specific test 👍)

[mcollina]

LGTM