feat: vercel json generator

packages/gatsby-plugin-vercel-json/gatsby-node.ts

@@ -1,24 +1,66 @@
 import fs from 'fs';
 import { resolve } from 'path';
 
-import type { GatsbyNode, Actions } from 'gatsby';
+import type { GatsbyNode, Actions, Page } from 'gatsby';
 
 type VercelRedirect = {
   source: string;
   destination: string;
   permanent?: boolean;
 };
 
+type VercelHeaders = {
+  source: string;
+  headers: {
+    key: string;
+    value: string;
+  }[];
+};
+
 type GatsbyRedirect = Parameters<Actions['createRedirect']>[0];
 
 type GatsbyState = {
   redirects: GatsbyRedirect[];
-  // pages: Map<string, Page>;
-  // program: { directory: string };
+  pages: Map<string, Page>;
+  program: { directory: string };
+};
+
+type PluginOptions = {
+  cleanUrls?: boolean;
+  headers: VercelHeaders[];
 };
 
-export const onPostBuild: GatsbyNode['onPostBuild'] = async ({ store }) => {
-  const { redirects }: GatsbyState = store.getState();
+export const pluginOptionsSchema: GatsbyNode['pluginOptionsSchema'] = ({
+  Joi,
+}) =>
+  Joi.object<PluginOptions>({
+    cleanUrls: Joi.boolean().default(false),
+    headers: Joi.array().items(
+      Joi.object({
+        source: Joi.string().required(),
+        headers: Joi.array()
+          .items(
+            Joi.object({
+              key: Joi.string().required(),
+              value: Joi.string().required(),
+            })
+          )
+          .required(),
+      })
+    ),
+  });
+
+export const onPostBuild: GatsbyNode['onPostBuild'] = async (
+  { store, reporter },
+  pluginOptions
+) => {
+  console.log(pluginOptions);
+  const { cleanUrls, headers } = pluginOptions as unknown as PluginOptions;
+  const { redirects, program }: GatsbyState = store.getState();
+
+  const publicDir = resolve(program.directory, 'public');
+  const vercelJsonPath = resolve(publicDir, 'vercel.json');
+  throw 1;
 
   const vercelRedirects: VercelRedirect[] = [];
   redirects.forEach((redirect) => {
@@ -29,11 +71,23 @@ export const onPostBuild: GatsbyNode['onPostBuild'] = async ({ store }) => {
     });
   });
 
+  if (redirects.length > 1024) {
+    reporter.panicOnBuild(
+      `Vercel supports redirects up to 1024, but got ${redirects.length}`
+    );
+  }
+
   // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const vercelJson = require('./vercel.json');
-  vercelJson.redirects = vercelRedirects;
-  await fs.promises.writeFile(
-    resolve('vercel.json'),
+  const vercelJson = {
+    cleanUrls,
+    headers,
+    // @todo get from config
+    trailingSlash: false,
+    redirects: vercelRedirects,
+  };
+
+  return fs.promises.writeFile(
+    vercelJsonPath,
     JSON.stringify(vercelJson, null, 2),
     'utf-8'
   );