启动Vite的createServer
为了能够了解vite里面运行了什么，通过执行单步调试能够更加直观的知道Vite具体内容。所以这次我们来试着启动Vite的createServer，并进行调试。
通过vite3安装一个vue的工程
进入工作目录，运行下面的代码，项目名称随意，语言用Vue。
npm create vite
进入工程目录安装依赖
添加断点并开启调试
通过vscode打开刚刚生成的项目，通过上一章的内容，可以知道程序的入口是cli.js。所以首先打开node_modules里面vite文件夹下面找到cli.js。找到运行dev时候的主要代码createServer，并打上断点。
开启vsCode的调试功能，JavaScript Debug Terminal
执行Dev命令,便可以运行到断点位置。
yarn run dev
边调试边理解代码
进入CreateServer内部代码,稍微加了一点注释，代码如下:
async function createServer(inlineConfig = {}) {
// 获取config，用户自定义的vite.config.js/ts,还有vite的默认配置
const config = await resolveConfig(inlineConfig, 'serve', 'development');
const { root, server: serverConfig } = config;
// http相关的配置
const httpsOptions = await resolveHttpsConfig(config.server.https);
// serverConfig就是vite.config里面的server对象，参照上main的代码，middlewareMode包含html和ssr 2个选项
const { middlewareMode } = serverConfig;
const resolvedWatchOptions = resolveChokidarOptions({
disableGlobbing: true,
...serverConfig.watch
});
// connect是一个中间件的类库，https://www.jianshu.com/p/d606c1059c51
const middlewares = connect();
const httpServer = middlewareMode
? null
: await resolveHttpServer(serverConfig, middlewares, httpsOptions);
const ws = createWebSocketServer(httpServer, config, httpsOptions);
if (httpServer) {
setClientErrorHandler(httpServer, config.logger);
}
// 监听文件变化
const watcher = chokidar.watch(path$n.resolve(root), resolvedWatchOptions);
// 创建模块图纸，记录每个模块之间的依赖关系
const moduleGraph = new ModuleGraph((url, ssr) => container.resolveId(url, undefined, { ssr }));
// 创建PluginContainer
const container = await createPluginContainer(config, moduleGraph, watcher);
// 关系HttpServer的时候的处理
const closeHttpServer = createServerCloseFn(httpServer);
let exitProcess;
// 创建Server对象
const server = {
config,
middlewares,
httpServer,
watcher,
pluginContainer: container,
ws,
moduleGraph,
resolvedUrls: null,
ssrTransform(code, inMap, url, originalCode = code) {
return ssrTransform(code, inMap, url, originalCode, server.config);
},
transformRequest(url, options) {
return transformRequest(url, server, options);
},
transformIndexHtml: null,
async ssrLoadModule(url, opts) {
if (isDepsOptimizerEnabled(config, true)) {
await initDevSsrDepsOptimizer(config, server);
}
await updateCjsSsrExternals(server);
return ssrLoadModule(url, server, undefined, undefined, opts?.fixStacktrace);
},
ssrFixStacktrace(e) {
if (e.stack) {
const stacktrace = ssrRewriteStacktrace(e.stack, moduleGraph);
rebindErrorStacktrace(e, stacktrace);
}
},
ssrRewriteStacktrace(stack) {
return ssrRewriteStacktrace(stack, moduleGraph);
},
async listen(port, isRestart) {
await startServer(server, port, isRestart);
if (httpServer) {
server.resolvedUrls = await resolveServerUrls(httpServer, config.server, config);
}
return server;
},
// 关闭server时调用的函数
async close() {
if (!middlewareMode) {
process.off('SIGTERM', exitProcess);
if (process.env.CI !== 'true') {
process.stdin.off('end', exitProcess);
}
}
await Promise.all([
watcher.close(),
ws.close(),
container.close(),
closeHttpServer()
]);
server.resolvedUrls = null;
},
printUrls() {
if (server.resolvedUrls) {
printServerUrls(server.resolvedUrls, serverConfig.host, config.logger.info);
}
else if (middlewareMode) {
throw new Error('cannot print server URLs in middleware mode.');
}
else {
throw new Error('cannot print server URLs before server.listen is called.');
}
},
async restart(forceOptimize) {
if (!server._restartPromise) {
server._forceOptimizeOnRestart = !!forceOptimize;
server._restartPromise = restartServer(server).finally(() => {
server._restartPromise = null;
server._forceOptimizeOnRestart = false;
});
}
return server._restartPromise;
},
_ssrExternals: null,
_restartPromise: null,
_importGlobMap: new Map(),
_forceOptimizeOnRestart: false,
_pendingRequests: new Map()
};
// vite.config里面申明了transformIndexHtml，在会被调用。
server.transformIndexHtml = createDevHtmlTransformFn(server);
if (!middlewareMode) {
exitProcess = async () => {
try {
await server.close();
}
finally {
process.exit();
}
};
// 进程收到这个信号时候，会调用exitProcess方法
process.once('SIGTERM', exitProcess);
if (process.env.CI !== 'true') {
process.stdin.on('end', exitProcess);
}
}
const { packageCache } = config;
const setPackageData = packageCache.set.bind(packageCache);
packageCache.set = (id, pkg) => {
if (id.endsWith('.json')) {
watcher.add(id);
}
return setPackageData(id, pkg);
};
// 文件发生变化时处理
watcher.on('change', async (file) => {
file = normalizePath$3(file);
if (file.endsWith('/package.json')) {
return invalidatePackageData(packageCache, file);
}
// invalidate module graph cache on file change
// 模型关系图变化时处理
moduleGraph.onFileChange(file);
if (serverConfig.hmr !== false) {
try {
await handleHMRUpdate(file, server);
}
catch (err) {
ws.send({
type: 'error',
err: prepareError(err)
});
}
}
});
watcher.on('add', (file) => {
handleFileAddUnlink(normalizePath$3(file), server);
});
watcher.on('unlink', (file) => {
handleFileAddUnlink(normalizePath$3(file), server);
});
if (!middlewareMode && httpServer) {
httpServer.once('listening', () => {
// update actual port since this may be different from initial value
serverConfig.port = httpServer.address().port;
});
}
// apply server configuration hooks from plugins
// 给plugin配置hook钩子
const postHooks = [];
for (const hook of config.getSortedPluginHooks('configureServer')) {
postHooks.push(await hook(server));
}
// Internal middlewares ------------------------------------------------------
// request timer
if (process.env.DEBUG) {
middlewares.use(timeMiddleware(root));
}
// cors (enabled by default)
const { cors } = serverConfig;
if (cors !== false) {
middlewares.use(lib$1.exports(typeof cors === 'boolean' ? {} : cors));
}
// proxy
const { proxy } = serverConfig;
if (proxy) {
middlewares.use(proxyMiddleware(httpServer, proxy, config));
}
// base
const devBase = config.base;
if (devBase !== '/') {
middlewares.use(baseMiddleware(server));
}
// open in editor support
middlewares.use('/__open-in-editor', launchEditorMiddleware());
// serve static files under /public
// this applies before the transform middleware so that these files are served
// as-is without transforms.
// 最外层public目录的配置
if (config.publicDir) {
middlewares.use(servePublicMiddleware(config.publicDir, config.server.headers));
}
// main transform middleware
// ✳️最核心的中间件--重点--javaScript的编译
middlewares.use(transformMiddleware(server));
// serve static files
// 管理静态资源的中间件
middlewares.use(serveRawFsMiddleware(server));
middlewares.use(serveStaticMiddleware(root, server));
// spa fallback
if (config.appType === 'spa') {
middlewares.use(spaFallbackMiddleware(root));
}
// run post config hooks
// This is applied before the html middleware so that user middleware can
// serve custom content instead of index.html.
// 自定义的中间件，这里运行
postHooks.forEach((fn) => fn && fn());
if (config.appType === 'spa' || config.appType === 'mpa') {
// transform index.html
middlewares.use(indexHtmlMiddleware(server));
// handle 404s
// Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
middlewares.use(function vite404Middleware(_, res) {
res.statusCode = 404;
res.end();
});
}
// error handler
// 处理错误
middlewares.use(errorMiddleware(server, middlewareMode));
let initingServer;
let serverInited = false;
const initServer = async () => {
if (serverInited) {
return;
}
if (initingServer) {
return initingServer;
}
initingServer = (async function () {
await container.buildStart({});
if (isDepsOptimizerEnabled(config, false)) {
// non-ssr
await initDepsOptimizer(config, server);
}
initingServer = undefined;
serverInited = true;
})();
return initingServer;
};
if (!middlewareMode && httpServer) {
// overwrite listen to init optimizer before server start
const listen = httpServer.listen.bind(httpServer);
httpServer.listen = (async (port, ...args) => {
try {
await initServer();
}
catch (e) {
httpServer.emit('error', e);
return;
}
return listen(port, ...args);
});
}
else {
await initServer();
}
return server;
}以上就是Vite的createServer启动源码解析的详细内容，更多关于Vite createServer启动的资料请关注阿兔在线工具其它相关文章！
