Add hasFlags

Check if the current process's arguments contain the specified flags.

snippets/hasFlags.md

@@ -0,0 +1,21 @@
+### hasFlags
+
+Check if the current process's arguments contain the specified flags.
+
+Use `Array.every()` and `Array.includes()` to check if `process.argv` contains all the specified flags.
+Use a regular expression to test if the specified flags are prefixed with `-` or `--` and prefix them accordingly.
+
+```js
+const hasFlags = (...flags) =>
+  flags.every(flag => process.argv.includes(
+    /^-{1,2}/.test(flag) ? flag : '--' + flag
+  ));
+```
+
+```js
+// node myScript.js -s --test --cool=true
+hasFlags('-s'); // true
+hasFlags('test', 'cool=true'); // true
+hasFlags('--test', 'cool=true', '-s'); // true
+hasFlags('special'); // false
+```