hydrogen-web/scripts/build-plugins/service-worker.js
2021-11-08 11:10:34 +01:00

114 lines
4.6 KiB
JavaScript

const fs = require('fs/promises');
const path = require('path');
const xxhash = require('xxhashjs');
function contentHash(str) {
var hasher = new xxhash.h32(0);
hasher.update(str);
return hasher.digest();
}
module.exports = function injectServiceWorker(swFile) {
let root;
let version;
let manifestHref;
return {
name: "injectServiceWorker",
apply: "build",
enforce: "post",
configResolved: config => {
root = config.root;
version = JSON.parse(config.define.HYDROGEN_VERSION); // unquote
},
generateBundle: async function(_, bundle) {
const absoluteSwFile = path.resolve(root, swFile);
const packageManifest = path.resolve(path.join(__dirname, "../../package.json"));
let swSource = await fs.readFile(absoluteSwFile, {encoding: "utf8"});
const assets = Object.values(bundle).filter(a => a.type === "asset");
const cachedFileNames = assets.map(o => o.fileName).filter(fileName => fileName !== "index.html");
const uncachedFileContentMap = {
"index.html": assets.find(o => o.fileName === "index.html").source,
"sw.js": swSource
};
const globalHash = getBuildHash(cachedFileNames, uncachedFileContentMap);
swSource = await buildServiceWorker(swSource, version, globalHash, assets);
const outputName = path.basename(absoluteSwFile);
// TODO: do normal build transformations for service worker too,
// I think if we emit it as a chunk rather than an asset it would
// but we can't emit chunks anymore in generateBundle I think ...
this.emitFile({
type: "asset",
fileName: outputName,
source: swSource
});
}
};
}
function getBuildHash(cachedFileNames, uncachedFileContentMap) {
const unhashedHashes = Object.entries(uncachedFileContentMap).map(([fileName, content]) => {
return `${fileName}-${contentHash(Buffer.from(content))}`;
});
const globalHashAssets = cachedFileNames.concat(unhashedHashes);
globalHashAssets.sort();
return contentHash(globalHashAssets.join(",")).toString();
}
const NON_PRECACHED_JS = [
"hydrogen-legacy.js",
"olm_legacy.js",
// most environments don't need the worker
"main.js"
];
function isPreCached(asset) {
const {name, fileName} = asset;
return name.endsWith(".svg") ||
name.endsWith(".png") ||
name.endsWith(".css") ||
name.endsWith(".wasm") ||
name.endsWith(".html") ||
// the index and vendor chunks don't have an extension in `name`, so check extension on `fileName`
fileName.endsWith(".js") && !NON_PRECACHED_JS.includes(path.basename(name));
}
async function buildServiceWorker(swSource, version, globalHash, assets) {
const unhashedPreCachedAssets = [];
const hashedPreCachedAssets = [];
const hashedCachedOnRequestAssets = [];
for (const asset of assets) {
const {name: unresolved, fileName: resolved} = asset;
if (!unresolved || resolved === unresolved) {
unhashedPreCachedAssets.push(resolved);
} else if (isPreCached(asset)) {
hashedPreCachedAssets.push(resolved);
} else {
hashedCachedOnRequestAssets.push(resolved);
}
}
const replaceArrayInSource = (name, value) => {
const newSource = swSource.replace(`${name} = []`, `${name} = ${JSON.stringify(value)}`);
if (newSource === swSource) {
throw new Error(`${name} was not found in the service worker source`);
}
return newSource;
};
const replaceStringInSource = (name, value) => {
const newSource = swSource.replace(new RegExp(`${name}\\s=\\s"[^"]*"`), `${name} = ${JSON.stringify(value)}`);
if (newSource === swSource) {
throw new Error(`${name} was not found in the service worker source`);
}
return newSource;
};
// write service worker
swSource = swSource.replace(`"%%VERSION%%"`, `"${version}"`);
swSource = swSource.replace(`"%%GLOBAL_HASH%%"`, `"${globalHash}"`);
swSource = replaceArrayInSource("UNHASHED_PRECACHED_ASSETS", unhashedPreCachedAssets);
swSource = replaceArrayInSource("HASHED_PRECACHED_ASSETS", hashedPreCachedAssets);
swSource = replaceArrayInSource("HASHED_CACHED_ON_REQUEST_ASSETS", hashedCachedOnRequestAssets);
swSource = replaceStringInSource("NOTIFICATION_BADGE_ICON", assets.find(a => a.name === "icon.png").fileName);
return swSource;
}