feat: parse --env.<flags> [WIP]

packages/webpack5/src/cli/parseEnvFlags.ts

@@ -0,0 +1,39 @@
+import { IWebpackEnv } from '@nativescript/webpack';
+
+const ENV_FLAG_RE = /--env\.(\w+)(?:=(.+))?/;
+
+export function parseEnvFlags(flags: string[]): IWebpackEnv {
+	const envFlags = flags.filter((flag) => flag.includes('--env.'));
+
+	const env = {};
+
+	envFlags.map((flag) => {
+		let [_, name, v] = ENV_FLAG_RE.exec(flag);
+		let value: any = v;
+
+		// convert --env.foo to --env.foo=true
+		if (value === undefined) {
+			value = true;
+		}
+
+		// convert true/false to boolean
+		if (value === 'true' || value === 'false') {
+			value = value === 'true';
+		}
+
+		// convert numbers
+		if (!isNaN(value) && !isNaN(parseFloat(value))) {
+			value = +value;
+		}
+
+		// duplicate key/name - convert to array
+		if (name in env && value) {
+			const orig = Array.isArray(env[name]) ? env[name] : [env[name]];
+			env[name] = [...orig, value];
+		} else {
+			env[name] = value;
+		}
+	});
+
+	return env;
+}