Document how to export the registry as executable and then build a schema from that in prod

[benjie]

Doing so is slightly safer than exporting the actual schema as executable because far fewer plugins interact with the gather phase, and thus fewer plugins need to explicitly support graphile-export. This pattern can thus be used as a stop-gap until all of the plugins you are using are graphile-export compatible.

Step 1: export the registry using something like this script:

import { writeFile } from "node:fs/promises";
import { buildInflection, gather } from "graphile-build";
import { resolvePresets } from "graphile-config";
import { exportValueAsString } from "graphile-export";
import preset from "./graphile.config.mjs";

const resolvedPreset = resolvePresets([preset]);
const inflection = buildInflection(resolvedPreset);
const input = await gather(resolvedPreset, { inflection });
const exportResult = await exportValueAsString("pgRegistry", input.pgRegistry, {
  mode: "graphql-js",
  prettier: true,
});

await writeFile(`${import.meta.dirname}/registry.mjs`, code);

await preset.pgServices[0].release();
console.log(`Registry written`);

Step 2: use the registry to build your schema, like in this (undocumented) example:

import { buildSchema } from "graphile-build";
import preset from "./graphile.config.mjs";
import { pgRegistry } from "./registry.mjs";

/** @type {GraphileBuild.BuildInput} */
const input = { pgRegistry }; 
export const schema = buildSchema(config, input); 

Step 3: serve the built schema via grafserv, e.g. using something like this example:

import { createServer } from "node:http"; 
import { grafserv } from "grafserv/node"; 
import { createWithPgClient } from "@dataplan/pg/adaptors/pg"; 
import preset from "./graphile.config.mjs";
import { schema } from "./schema"; 

const serv = grafserv({ preset, schema }); 
const server = createServer(); 
serv.addTo(server); 
server.listen(5555);