Speed up TypeScript projects

packages/react-dev-utils/WebpackDevServerUtils.js

@@ -17,22 +17,9 @@ const inquirer = require('inquirer');
 const clearConsole = require('./clearConsole');
 const formatWebpackMessages = require('./formatWebpackMessages');
 const getProcessForPort = require('./getProcessForPort');
+const typescriptFormatter = require('./typescriptFormatter');
 
 const isInteractive = process.stdout.isTTY;
-let handleCompile;
-
-// You can safely remove this after ejecting.
-// We only use this block for testing of Create React App itself:
-const isSmokeTest = process.argv.some(arg => arg.indexOf('--smoke-test') > -1);
-if (isSmokeTest) {
-  handleCompile = (err, stats) => {
-    if (err || stats.hasErrors() || stats.hasWarnings()) {
-      process.exit(1);
-    } else {
-      process.exit(0);
-    }
-  };
-}
 
 function prepareUrls(protocol, host, port) {
   const formatUrl = hostname =>
@@ -113,12 +100,12 @@ function printInstructions(appName, urls, useYarn) {
   console.log();
 }
 
-function createCompiler(webpack, config, appName, urls, useYarn) {
+function createCompiler(webpack, config, appName, urls, useYarn, useTypeScript, devSocket) {
   // "Compiler" is a low-level interface to Webpack.
   // It lets us listen to some events and provide our own custom messages.
   let compiler;
   try {
-    compiler = webpack(config, handleCompile);
+    compiler = webpack(config);
   } catch (err) {
     console.log(chalk.red('Failed to compile.'));
     console.log();
@@ -139,10 +126,30 @@ function createCompiler(webpack, config, appName, urls, useYarn) {
   });
 
   let isFirstCompile = true;
+  let tsMessagesPromise;
+  let tsMessagesResolver;
+
+  if (useTypeScript) {
+    compiler.hooks.beforeCompile.tap('beforeCompile', () => {
+      tsMessagesPromise = new Promise(resolve => {
+        tsMessagesResolver = msgs => resolve(msgs);
+      });
+    });
+
+    compiler.hooks.forkTsCheckerReceive.tap('afterTypeScriptCheck', (diagnostics, lints) => {
+      const allMsgs = [...diagnostics, ...lints];
+      const format = message =>`${message.file}\n${typescriptFormatter(message, true)}`;
+
+      tsMessagesResolver({
+        errors: allMsgs.filter(msg => msg.severity === 'error').map(format),
+        warnings: allMsgs.filter(msg => msg.severity === 'warning').map(format),
+      });
+    });
+  }
 
   // "done" event fires when Webpack has finished recompiling the bundle.
   // Whether or not you have warnings or errors, you will get this event.
-  compiler.hooks.done.tap('done', stats => {
+  compiler.hooks.done.tap('done', async stats => {
     if (isInteractive) {
       clearConsole();
     }
@@ -152,9 +159,32 @@ function createCompiler(webpack, config, appName, urls, useYarn) {
     // them in a readable focused way.
     // We only construct the warnings and errors for speed:
     // https://github.com/facebook/create-react-app/issues/4492#issuecomment-421959548
-    const messages = formatWebpackMessages(
-      stats.toJson({ all: false, warnings: true, errors: true })
-    );
+    const statsData = stats.toJson({ all: false, warnings: true, errors: true });
+
+    if (useTypeScript && statsData.errors.length === 0) {
+      process.stdout.write(
+        chalk.yellow('Files successfully emitted, waiting for typecheck results...')
+      );
+
+      const messages = await tsMessagesPromise;
+      statsData.errors.push(...messages.errors);
+      statsData.warnings.push(...messages.warnings);
+      // Push errors and warnings into compilation result
+      // to show them after page refresh triggered by user.
+      stats.compilation.errors.push(...messages.errors);
+      stats.compilation.warnings.push(...messages.warnings);
+
+      if (messages.errors.length > 0) {
+        devSocket.errors(messages.errors);
+      } else if (messages.warnings.length > 0) {
+        devSocket.warnings(messages.warnings);
+      }
+
+      process.stdout.clearLine();
+      process.stdout.cursorTo(0);
+    }
+
+    const messages = formatWebpackMessages(statsData);
     const isSuccessful = !messages.errors.length && !messages.warnings.length;
     if (isSuccessful) {
       console.log(chalk.green('Compiled successfully!'));
@@ -194,6 +224,25 @@ function createCompiler(webpack, config, appName, urls, useYarn) {
       );
     }
   });
+
+  // You can safely remove this after ejecting.
+  // We only use this block for testing of Create React App itself:
+  const isSmokeTest = process.argv.some(arg => arg.indexOf('--smoke-test') > -1);
+  if (isSmokeTest) {
+    compiler.hooks.failed.tap('smokeTest', async () => {
+      await tsMessagesPromise;
+      process.exit(1)
+    });
+    compiler.hooks.done.tap('smokeTest', async stats => {
+      await tsMessagesPromise;
+      if (stats.hasErrors() || stats.hasWarnings()) {
+        process.exit(1);
+      } else {
+        process.exit(0);
+      }
+    });
+  }
+
   return compiler;
 }
 

packages/react-dev-utils/typescriptFormatter.js

@@ -45,12 +45,15 @@ function formatter(message, useColors) {
   }
 
   const severity = hasGetters ? message.getSeverity() : message.severity;
+  const types = { diagnostic: 'TypeScript', lint: 'TSLint' };
 
   return [
-    messageColor.bold(`Type ${severity.toLowerCase()}: `) +
+    messageColor.bold(`${types[message.type]} ${severity.toLowerCase()}: `) +
       (hasGetters ? message.getContent() : message.content) +
       '  ' +
-      messageColor.underline(`TS${message.code}`),
+      messageColor.underline(
+        (message.type === 'lint' ? 'Rule: ' : 'TS') + message.code
+      ),
     '',
     frame,
   ].join(os.EOL);

packages/react-dev-utils/webpackHotDevClient.js

@@ -140,19 +140,15 @@ function handleWarnings(warnings) {
     }
   }
 
+  printWarnings();
+
   // Attempt to apply hot updates or reload.
   if (isHotUpdate) {
     tryApplyUpdates(function onSuccessfulHotUpdate() {
-      // Only print warnings if we aren't refreshing the page.
-      // Otherwise they'll disappear right away anyway.
-      printWarnings();
       // Only dismiss it when we're sure it's a hot update.
       // Otherwise it would flicker right before the reload.
       ErrorOverlay.dismissBuildError();
     });
-  } else {
-    // Print initial warnings immediately.
-    printWarnings();
   }
 }
 

packages/react-scripts/config/webpack.config.js

@@ -619,7 +619,7 @@ module.exports = function(webpackEnv) {
           typescript: resolve.sync('typescript', {
             basedir: paths.appNodeModules,
           }),
-          async: false,
+          async: isEnvDevelopment,
           checkSyntacticErrors: true,
           tsconfig: paths.appTsConfig,
           compilerOptions: {
@@ -640,7 +640,7 @@ module.exports = function(webpackEnv) {
           ],
           watch: paths.appSrc,
           silent: true,
-          formatter: typescriptFormatter,
+          formatter: isEnvProduction ? typescriptFormatter : undefined,
         }),
     ].filter(Boolean),
     // Some libraries import Node modules but don't use them in the browser.

packages/react-scripts/scripts/start.js

@@ -94,9 +94,14 @@ checkBrowsers(paths.appPath, isInteractive)
     const config = configFactory('development');
     const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
     const appName = require(paths.appPackageJson).name;
+    const useTypeScript = fs.existsSync(paths.appTsConfig);
     const urls = prepareUrls(protocol, HOST, port);
+    const devSocket = {
+      warnings: warnings => devServer.sockWrite(devServer.sockets, 'warnings', warnings),
+      errors: errors => devServer.sockWrite(devServer.sockets, 'errors', errors),
+    };
     // Create a webpack compiler that is configured with custom messages.
-    const compiler = createCompiler(webpack, config, appName, urls, useYarn);
+    const compiler = createCompiler(webpack, config, appName, urls, useYarn, useTypeScript, devSocket);
     // Load proxy config
     const proxySetting = require(paths.appPackageJson).proxy;
     const proxyConfig = prepareProxy(proxySetting, paths.appPublic);