Inital build

frontend/node_modules/custom-error-instance/examples/map.js

@@ -0,0 +1,25 @@
+"use strict";
+var CustomError = require('../index');
+var store = {};
+
+var Err = CustomError('MapError');
+Err.inuse = CustomError(Err, { message: 'The specified key is already in use.', code: 'INUSE' });
+
+function add(key, value) {
+    if (Math.random() < .3) throw new Err('Random Error');
+    if (store.hasOwnProperty(key)) throw new Err.inuse();
+    store[key] = value;
+}
+
+try {
+    add('x', 1);
+    add('x', 2);
+} catch (e) {
+    if (e instanceof Err.inuse) {
+        console.error(e.toString());        // "MapError INUSE: The specified key is already in use."
+    } else if (e instanceof Err) {
+        console.error('Unexpected ' + e);   // "Unexpected MapError: Random Error"
+    } else {
+        throw e;
+    }
+}