@expo/metro-config
Version:
A Metro config for running React Native projects with the Metro bundler
118 lines • 5.71 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.getEnvVarDevString = exports.environmentVariableSerializerPlugin = exports.serverPreludeSerializerPlugin = exports.getTransformEnvironment = void 0;
const CountingSet_1 = __importDefault(require("metro/src/lib/CountingSet"));
const countLines_1 = __importDefault(require("metro/src/lib/countLines"));
const debug = require('debug')('expo:metro-config:serializer:env-var');
function getTransformEnvironment(url) {
const match = url.match(/[&?]transform\.environment=([^&]+)/);
return match ? match[1] : null;
}
exports.getTransformEnvironment = getTransformEnvironment;
function getAllExpoPublicEnvVars(inputEnv = process.env) {
// Create an object containing all environment variables that start with EXPO_PUBLIC_
const env = {};
for (const key in inputEnv) {
if (key.startsWith('EXPO_PUBLIC_')) {
// @ts-expect-error: TS doesn't know that the key starts with EXPO_PUBLIC_
env[key] = inputEnv[key];
}
}
return env;
}
function isServerEnvironment(graph, options) {
// Requests from a dev server will use sourceUrl.
if (!graph.transformOptions.customTransformOptions) {
if (options.sourceUrl) {
const env = getTransformEnvironment(options.sourceUrl);
return env === 'node' || env === 'react-server';
}
return false;
}
// Other requests will use customTransformOptions.environment.
const env = graph.transformOptions.customTransformOptions.environment;
return env === 'node' || env === 'react-server';
}
/** Strips the process.env polyfill in server environments to allow for accessing environment variables off the global. */
function serverPreludeSerializerPlugin(entryPoint, preModules, graph, options) {
if (isServerEnvironment(graph, options)) {
const prelude = preModules.find((module) => module.path === '__prelude__');
if (prelude) {
debug('Stripping environment variable polyfill in server environment.');
prelude.output[0].data.code = prelude.output[0].data.code
.replace(/process=this\.process\|\|{},/, '')
.replace(/process\.env=process\.env\|\|{};process\.env\.NODE_ENV=process\.env\.NODE_ENV\|\|"\w+";/, '');
}
}
return [entryPoint, preModules, graph, options];
}
exports.serverPreludeSerializerPlugin = serverPreludeSerializerPlugin;
function environmentVariableSerializerPlugin(entryPoint, preModules, graph, options) {
// Skip replacement in Node.js environments.
if (isServerEnvironment(graph, options)) {
debug('Skipping environment variable inlining in Node.js environment.');
return [entryPoint, preModules, graph, options];
}
// In development, we need to add the process.env object to ensure it
// persists between Fast Refresh updates.
if (!options.dev) {
debug('Skipping environment variable inlining in production environment in favor of babel-preset-expo inlining with source maps.');
return [entryPoint, preModules, graph, options];
}
const code = getEnvVarDevString();
const prelude = preModules.find((module) => module.path === '\0polyfill:environment-variables');
if (prelude) {
debug('Injecting environment variables in virtual module.');
// !!MUST!! be one line in order to ensure Metro's asymmetric serializer system can handle it.
prelude.output[0].data.code = code;
return [entryPoint, preModules, graph, options];
}
// Old system which doesn't work very well since Metro doesn't serialize graphs the same way in all cases.
// e.g. the `.map` endpoint is serialized differently to error symbolication.
// Inject the new module at index 1
// @ts-expect-error: The preModules are mutable and we need to mutate them in order to ensure the changes are applied outside of the serializer.
preModules.splice(
// Inject at index 1 to ensure it runs after the prelude (which injects env vars).
1, 0, getEnvPrelude(code));
return [entryPoint, preModules, graph, options];
}
exports.environmentVariableSerializerPlugin = environmentVariableSerializerPlugin;
function getEnvVarDevString(env = process.env) {
// Set the process.env object to the current environment variables object
// ensuring they aren't iterable, settable, or enumerable.
const str = `process.env=Object.defineProperties(process.env, {` +
Object.keys(getAllExpoPublicEnvVars(env))
.map((key) => `${JSON.stringify(key)}: { value: ${JSON.stringify(env[key])} }`)
.join(',') +
'});';
const code = '/* HMR env vars from Expo CLI (dev-only) */ ' + str;
const lineCount = (0, countLines_1.default)(code);
if (lineCount !== 1) {
throw new Error(`Virtual environment variable code must be one line, got "${lineCount}" lines.`);
}
return code;
}
exports.getEnvVarDevString = getEnvVarDevString;
function getEnvPrelude(code) {
const name = `\0polyfill:environment-variables`;
return {
dependencies: new Map(),
getSource: () => Buffer.from(code),
inverseDependencies: new CountingSet_1.default(),
path: name,
output: [
{
type: 'js/script/virtual',
data: {
code,
lineCount: 1,
map: [],
},
},
],
};
}
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