refactor to build pages->headers map during onPostBuild

- refactor `header-builder.ts` to loop through all possible pages/files and add their matching headers during `onPostBuild`
- refactor `headers.ts` fastify plugin to look up headers for the path and add them, alongside default security, respecting overwrite precedence
- add `reply.mode` and `reply.path` decorators to support adding headers to dynamic routes via the matched path rather than `request.url`
- add tests to support feature table in #392, specifically: #392 (comment)

integration-tests/plugin-fastify/gatsby-config.js

@@ -30,7 +30,7 @@ module.exports = {
           headers: {
             customHeaders: {
               "/posts/page-1*": {
-                "x-test-page-specific": "shows on /posts/page-1 and its page-data",
+                "x-test-page-specific": "shows on /posts/page-1",
               },
               "/posts/page-2*": {
                 "X-Content-Type-Options": "nosniff by default, overwritten for this page",
@@ -50,6 +50,16 @@ module.exports = {
                 "x-test-ssr-kept": "ssr page",
                 "x-test-ssr-overwrite": "ssr page",
               },
+              "/api/test": {
+                "x-test-function-kept": "function page",
+                "x-test-function-overwrite": "function page",
+              },
+              "/generated/page-6": {
+                "x-test-dsg-kept": "dsg page",
+              },
+              "/page-data/generated/page-6/page-data.json": {
+                "x-test-dsg-kept": "dsg page data",
+              },
               "/posts/page-1/index.html": {
                 "x-test-page-specific": "shows on /posts/page-1 and its page-data (overwritten)",
               },

integration-tests/plugin-fastify/src/api/test.js

@@ -271,8 +271,12 @@ const responseData = [
 
 export default function handler(req, res) {
   if (isGatsbyHosting(res)) {
+    res.setHeader("x-test-function-overwrite", "Overwritten by FUNCTION");
     res.status(200).send(responseData);
   } else {
+    res.headers({
+      "x-test-function-overwrite": "Overwritten by FUNCTION",
+    });
     res.code(200).send(responseData);
   }
 }

integration-tests/plugin-fastify/src/pages/index.js

@@ -1,5 +1,6 @@
 import * as React from "react";
 import { Link, withPrefix } from "gatsby";
+import { StaticImage } from "gatsby-plugin-image";
 
 import "../../src/styles/test.css";
 
@@ -156,6 +157,8 @@ const IndexPage = () => {
           <a href={withPrefix("/ssr_named_splat/test/path")}>Named Splat routed SSR page</a>
         </li>
       </ul>
+
+      <StaticImage src="../images/icon.png" alt="Icon" layout="fixed" width={165} />
     </main>
   );
 };

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/app-hash.js

@@ -0,0 +1 @@
+console.log("Hello from app-hash.js");

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/component-fake-hash.js

@@ -0,0 +1 @@
+console.log("Hellow from component-fake-hash.js");

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/css-hash.css

@@ -0,0 +1 @@
+body { border: 1px solid red; }

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/fake-chunk.js

@@ -0,0 +1 @@
+console.log("Hello from fake-chunk.js");

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/fake-lazycomponent.js

@@ -1 +1 @@
-console.log("this is a fake lazy component");
+console.log("Hello from fake-lazycomponent.js");

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/page-data/app-data.json

@@ -0,0 +1 @@
+{"webpackCompilationHash":"cf2f9feb0b0d2002462c"}

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/page-data/posts/page-1/page-data.json

@@ -0,0 +1 @@
+{"componentChunkName":"component---src-pages-posts-page-1-js","path":"/posts/page-1/","result":{"pageContext":{}},"staticQueryHashes":[],"slicesMap":{}}

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/page-data/posts/page-2/page-data.json

@@ -0,0 +1 @@
+{"componentChunkName":"component---src-pages-posts-page-2-js","path":"/posts/page-2/","result":{"pageContext":{}},"staticQueryHashes":[],"slicesMap":{}}

packages/gatsby-plugin-fastify/src/__tests__/__files__/public/page-data/posts/page-3/page-data.json

@@ -0,0 +1 @@
+{"componentChunkName":"component---src-pages-posts-page-3-js","path":"/posts/page-3/","result":{"pageContext":{}},"staticQueryHashes":[],"slicesMap":{}}

packages/gatsby-plugin-fastify/src/__tests__/__utils__/config.js

@@ -18,6 +18,28 @@ export function createCliConfig({ host, port, logLevel, open }) {
 export async function createFastifyInstance(plugin) {
   const config = getConfig();
 
+  config.server.headers = {
+    ...config.server.headers,
+    "/component-fake-hash.js": {
+      "cache-control": "public, max-age=31536000, immutable",
+      "x-test-js": "root js file",
+      "x-cache-control": "overwrite cache-control for all root js files",
+      "x-test-all-pages": "shows on every page/file",
+    },
+    "/_gatsby/image/hash/hash/indonesia.jpg": {
+      "cache-control": "undefined",
+      "x-test-all-pages": "shows on every page/file",
+    },
+    "/static/hash/hash/icon.png": {
+      "cache-control": "public, max-age=31536000, immutable",
+      "x-test-all-pages": "shows on every page/file",
+    },
+    "/fake-lazycomponent.js": {
+      "cache-control": "undefined",
+      "x-test-all-pages": "shows on every page/file",
+    },
+  };
+
   const fastify = Fastify(createFastifyConfig(config));
 
   await fastify.register(plugin, { prefix: config.server.prefix });

packages/gatsby-plugin-fastify/src/__tests__/gatsby-node.js

@@ -2,6 +2,13 @@ import fs from "fs-extra";
 import mockPath from "node:path";
 import { onPostBuild } from "../gatsby-node";
 
+function mockPosixJoin(...paths) {
+  return mockPath
+    .join(...paths)
+    .split(mockPath.sep)
+    .join(mockPath.posix.sep);
+}
+
 jest.mock("../utils/constants", () => ({
   ...jest.requireActual("../utils/constants"),
   PATH_TO_FUNCTIONS: "../../integration-tests/plugin-fastify/.cache/functions/",
@@ -12,7 +19,7 @@ jest.mock("../utils/constants", () => ({
 
 jest.mock("fs-extra", () => ({
   existsSync: jest.fn((filePath) => {
-    if (filePath.includes(mockPath.join(".cache", "functions"))) {
+    if (filePath.includes(mockPosixJoin(".cache", "functions"))) {
       return true;
     }
     return false;
@@ -51,30 +58,31 @@ jest.mock("fs-extra", () => ({
   }),
 }));
 
+const mockPages = [
+  {
+    fakePage: "fakeValue",
+    path: "/",
+  },
+  {
+    matchPath: "/app/*",
+    path: "/app/[...]/",
+  },
+  {
+    path: "/ssr",
+    mode: "SSR",
+  },
+  {
+    path: "/my/dsg/path",
+    mode: "DSG",
+  },
+];
 const pathPrefix = "/test";
 const store = {
   getState: jest.fn(() => ({
     program: {
       directory: "",
     },
-    pages: [
-      {
-        fakePage: "fakeValue",
-        path: "/",
-      },
-      {
-        matchPath: "/app/*",
-        path: "/app/[...]/",
-      },
-      {
-        path: "/ssr",
-        mode: "SSR",
-      },
-      {
-        path: "/my/dsg/path",
-        mode: "DSG",
-      },
-    ],
+    pages: mockPages,
     redirects: [
       {
         fromPath: "/perm-redirect",
@@ -102,6 +110,24 @@ const store = {
   })),
 };
 
+jest.mock("../utils/plugin-data", () => ({
+  ...jest.requireActual("../utils/plugin-data"),
+  makePluginData: jest.fn(() => ({
+    pages: new Map(Object.entries(mockPages).map(([key, value]) => [key, value])),
+    components: [],
+    manifest: [],
+    program: {},
+    pathPrefix: "",
+    publicFolder: jest.fn(() => "/public"),
+    functionsFolder: jest.fn((file) =>
+      file ? mockPosixJoin(".cache", "functions", file) : mockPosixJoin(".cache", "functions")
+    ),
+    configFolder: jest.fn((file) =>
+      file ? mockPosixJoin(".cache", file) : mockPosixJoin(".cache")
+    ),
+  })),
+}));
+
 const reporter = {
   error: jest.fn((_message, error) => {
     throw new Error(error);
@@ -125,7 +151,7 @@ describe(`Gatsby Node API`, () => {
 
     const writeJSONCall = fs.writeJSON.mock.calls[0];
     expect(fs.writeJSON).toHaveBeenCalledTimes(1);
-    expect(writeJSONCall[0]).toContain(mockPath.join(".cache", "gatsby-plugin-fastify.json"));
+    expect(writeJSONCall[0]).toContain(mockPosixJoin(".cache", "gatsby-plugin-fastify.json"));
     expect(writeJSONCall[1]).toMatchSnapshot();
   });
 });