vite-plugin-top-level-await
Version:
Transform code to support top-level await in normal browsers for Vite.
160 lines (159 loc) • 7.65 kB
JavaScript
;
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
var desc = Object.getOwnPropertyDescriptor(m, k);
if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = topLevelAwait;
const path_1 = __importDefault(require("path"));
const rollup_1 = require("rollup");
const plugin_virtual_1 = __importDefault(require("@rollup/plugin-virtual"));
const SWC = __importStar(require("@swc/core"));
const esbuild_1 = __importDefault(require("./esbuild"));
const options_1 = require("./options");
const bundle_info_1 = require("./bundle-info");
const transform_1 = require("./transform");
// Use the same default target as Vite.
// https://github.com/vitejs/vite/blob/v6.0.7/packages/vite/src/node/constants.ts#L70-L76
const DEFAULT_VITE_TARGET = ["es2020", "edge88", "firefox78", "chrome87", "safari14"];
function topLevelAwait(options) {
const resolvedOptions = {
...options_1.DEFAULT_OPTIONS,
...(options || {})
};
let isWorker = false;
let isWorkerIifeRequested = false;
let assetsDir = "";
let buildTarget;
let minify;
const buildRawTarget = async (code) => {
return (await esbuild_1.default.transform(code, {
minify,
target: buildTarget,
format: "esm"
})).code;
};
return {
name: "vite-plugin-top-level-await",
enforce: "post",
outputOptions(options) {
if (isWorker && options.format === "iife") {
// The the worker bundle's output format to ES to allow top-level awaits
// We'll use another rollup build to convert it back to IIFE
options.format = "es";
isWorkerIifeRequested = true;
}
},
config(config, env) {
var _a, _b;
if (env.command === "build") {
if (config.worker) {
isWorker = true;
}
// By default Vite transforms code with esbuild with target for a browser list with ES modules support
// This cause esbuild to throw an exception when there're top-level awaits in code
// Let's backup the original target and override the esbuild target with "esnext", which allows TLAs.
// If the user doesn't specify a target explicitly, `config.build.target` will be undefined and we'll
// use the default Vite target.
buildTarget = (_a = config.build.target) !== null && _a !== void 0 ? _a : DEFAULT_VITE_TARGET;
config.build.target = "esnext";
minify = !!config.build.minify;
assetsDir = config.build.assetsDir;
}
if (env.command === "serve") {
// Fix errors in NPM packages which are getting pre-processed in development build
if ((_b = config.optimizeDeps) === null || _b === void 0 ? void 0 : _b.esbuildOptions) {
config.optimizeDeps.esbuildOptions.target = "esnext";
}
}
},
async generateBundle(bundleOptions, bundle) {
// Process ES modules (modern) target only since TLAs in legacy builds are handled by SystemJS
if (bundleOptions.format !== "es")
return;
const bundleChunks = Object.fromEntries(Object.entries(bundle)
.filter(([, item]) => item.type === "chunk")
.map(([key, item]) => [key, item.code]));
const bundleAsts = await (0, bundle_info_1.parseBundleAsts)(bundleChunks);
const bundleInfo = await (0, bundle_info_1.parseBundleInfo)(bundleAsts);
await Promise.all(Object.keys(bundleChunks).map(async (moduleName) => {
if (!bundleInfo[moduleName].transformNeeded) {
if (buildTarget !== "esnext") {
bundle[moduleName].code = await buildRawTarget(bundleChunks[moduleName]);
}
return;
}
const newAst = (0, transform_1.transformModule)(bundleChunks[moduleName], bundleAsts[moduleName], moduleName, bundleInfo, resolvedOptions);
let code = SWC.printSync(newAst, { minify }).code;
if (buildTarget !== "esnext") {
code = await buildRawTarget(code);
}
bundle[moduleName].code = code;
}));
if (isWorker && isWorkerIifeRequested) {
// Get the entry chunk
const chunkNames = Object.keys(bundle).filter(key => bundle[key].type === "chunk");
const entry = chunkNames.find(key => bundle[key].isEntry);
if (!entry) {
throw new Error(`Entry not found in worker bundle! Please submit an issue with a reproducible project.`);
}
// Build a new bundle to convert ESM to IIFE
// Assets are not touched
const newBuild = await (0, rollup_1.rollup)({
input: entry,
plugins: [(0, plugin_virtual_1.default)(Object.fromEntries(chunkNames.map(key => [key, bundle[key].code])))]
});
// IIFE bundle is always a single file
const { output: [newEntry] } = await newBuild.generate({
format: "iife",
entryFileNames: path_1.default.posix.join(assetsDir, "[name].js")
});
// Postprocess and minify (if requested) with ESBuild
newEntry.code = (await esbuild_1.default.transform(
// Polyfill `document.currentScript.src` since it's used for `import.meta.url`.
`self.document = { currentScript: { src: self.location.href } };\n${newEntry.code}`, {
minify,
target: buildTarget
})).code;
// Remove extra chunks and replace ESM entry with IIFE entry
for (const chunkName of chunkNames) {
if (chunkName !== entry)
delete bundle[chunkName];
}
bundle[entry] = newEntry;
}
}
};
}