初始化

webpack/build.config.utils.ts

@@ -0,0 +1,40 @@
+import * as fs from 'fs';
+import * as path from 'path';
+
+type BuildConfig = Record<string, boolean | string>;
+
+const DEFAULT_CONFIG_PATH = path.resolve(path.dirname(__filename), 'default.build.config.json');
+const configCache: Map<string, BuildConfig> = new Map();
+const mergedCache: Map<string, BuildConfig> = new Map();
+
+export function getConfig(filename: string): BuildConfig {
+    let cached = configCache.get(filename);
+    if (!cached) {
+        const filtered: BuildConfig = {};
+        const absolutePath = path.isAbsolute(filename) ? filename : path.resolve(process.cwd(), filename);
+        const rawConfig = JSON.parse(fs.readFileSync(absolutePath).toString());
+        Object.keys(rawConfig).forEach((key) => {
+            const value = rawConfig[key];
+            if (typeof value === 'boolean' || typeof value === 'string') {
+                filtered[key] = value;
+            }
+        });
+        cached = filtered;
+        configCache.set(filename, cached);
+    }
+    return cached;
+}
+
+export function mergeWithDefaultConfig(custom?: string): BuildConfig {
+    if (!custom) {
+        return getConfig(DEFAULT_CONFIG_PATH);
+    }
+    let cached = mergedCache.get(custom);
+    if (!cached) {
+        const defaultConfig = getConfig(DEFAULT_CONFIG_PATH);
+        const customConfig = getConfig(custom);
+        cached = Object.assign({}, defaultConfig, customConfig);
+        mergedCache.set(custom, cached);
+    }
+    return cached;
+}