feature: Adding Typescript block (#21)

lib/blocks/index.js

@@ -1,5 +1,6 @@
 const handleAssets = require("./assets");
 const handleJs = require("./babel");
+const handleTs = require("./typescript");
 const handleCss = require("./css");
 const handleScss = require("./scss");
 const configEntries = require("./entry");
@@ -14,6 +15,7 @@ const utilities = require("./utility");
 module.exports = {
     handleAssets,
     handleJs,
+    handleTs,
     handleCss,
     handleScss,
     configEntries,

lib/blocks/typescript.js

@@ -0,0 +1,71 @@
+const ForkTsCheckerWebpackPlugin = require("fork-ts-checker-webpack-plugin");
+const { cpus } = require("os");
+
+const { ensureConfig, safeMerge, deduplicate } = require("../utils");
+
+module.exports = blockConfig => (processEnv, argv) => argConfig => {
+    const isDev = processEnv.NODE_ENV === "development";
+    const isHotReload = processEnv.HOT_RELOAD === "true";
+
+    const defaultConf = {
+        useCache: isDev,
+        mode: processEnv.NODE_ENV,
+        hot: isHotReload,
+        test: /\.(ts|tsx)$/,
+        exclude: /node_modules/,
+        extensions: [".ts", ".tsx"]
+    };
+
+    const mergedConf = safeMerge(defaultConf, blockConfig);
+    const config = ensureConfig(argConfig);
+
+    config.module.rules.push({
+        test: mergedConf.test,
+        exclude: mergedConf.exclude,
+        use: [
+            {
+                loader: "thread-loader",
+                options: {
+                    // Let's leave 1 cpu free, for async type checking
+                    workers: Math.max(cpus().length - (mergedConf.hot ? 1 : 0), 1)
+                }
+            },
+            mergedConf.useCache && {
+                loader: "cache-loader"
+            },
+            {
+                loader: "babel-loader",
+                options: {
+                    cacheDirectory: false,
+                    presets: [
+                        [
+                            "@thc/babel-preset-react",
+                            {
+                                mode: mergedConf.mode,
+                                hot: mergedConf.hot
+                            }
+                        ]
+                    ],
+                    babelrc: false
+                }
+            },
+            {
+                loader: "ts-loader",
+                options: {
+                    transpileOnly: true // Leave type checking to plugin
+                }
+            }
+        ].filter(Boolean)
+    });
+
+    config.plugins.push(
+        new ForkTsCheckerWebpackPlugin({
+            tslint: true,
+            async: mergedConf.hot
+        })
+    );
+
+    config.resolve.extensions = deduplicate(config.resolve.extensions, mergedConf.extensions);
+
+    return config;
+};