docs: document esm features

Author: ctavan

README.md

@@ -9,88 +9,104 @@ Simple, fast generation of [RFC4122](http://www.ietf.org/rfc/rfc4122.txt) UUIDS.
 Features:
 
 * Support for version 1, 3, 4 and 5 UUIDs
-* Cross-platform
+* Cross-platform: CommonJS build for Node.js and [ECMAScript Modules](#ecmascript-modules) for the
+  browser.
 * Uses cryptographically-strong random number APIs (when available)
 * Zero-dependency, small footprint (... but not [this small](https://github.com/__gist/982883))
 
-[**Deprecation warning**: The use of `require('uuid')` is deprecated and will not be
-supported after version 3.x of this module.  Instead, use `require('uuid/[v1|v3|v4|v5]')` as shown in the examples below.]
-
-## Quickstart - CommonJS (Recommended)
+## Quickstart - Node.js/CommonJS
 
 ```shell
 npm install uuid
 ```
 
-Then generate your uuid version of choice ...
+Then generate a random UUID (v4 algorithm), which is almost always what you want ...
+
+Version 4 (random):
+
+```javascript
+const uuid = require('uuid');
+uuid.v4(); // ⇨ '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'
+
+```
+
+Or generate UUIDs with other algorithms of your choice ...
 
 Version 1 (timestamp):
 
 ```javascript
-const uuidv1 = require('uuid/v1');
-uuidv1(); // ⇨ '2c5ea4c0-4067-11e9-8bad-9b1deb4d3b7d'
+const uuid = require('uuid');
+uuid.v1(); // ⇨ '2c5ea4c0-4067-11e9-8b2d-1b9d6bcdbbfd'
 
 ```
 
 Version 3 (namespace):
 
 ```javascript
-const uuidv3 = require('uuid/v3');
+const uuid = require('uuid');
 
 // ... using predefined DNS namespace (for domain names)
-uuidv3('hello.example.com', uuidv3.DNS); // ⇨ '9125a8dc-52ee-365b-a5aa-81b0b3681cf6'
+uuid.v3('hello.example.com', uuid.v3.DNS); // ⇨ '9125a8dc-52ee-365b-a5aa-81b0b3681cf6'
 
 // ... using predefined URL namespace (for, well, URLs)
-uuidv3('http://example.com/hello', uuidv3.URL); // ⇨ 'c6235813-3ba4-3801-ae84-e0a6ebb7d138'
+uuid.v3('http://example.com/hello', uuid.v3.URL); // ⇨ 'c6235813-3ba4-3801-ae84-e0a6ebb7d138'
 
 // ... using a custom namespace
 //
 // Note: Custom namespaces should be a UUID string specific to your application!
 // E.g. the one here was generated using this modules `uuid` CLI.
 const MY_NAMESPACE = '1b671a64-40d5-491e-99b0-da01ff1f3341';
-uuidv3('Hello, World!', MY_NAMESPACE); // ⇨ 'e8b5a51d-11c8-3310-a6ab-367563f20686'
-
-```
-
-Version 4 (random):
-
-```javascript
-const uuidv4 = require('uuid/v4');
-uuidv4(); // ⇨ '1b9d6bcd-bbfd-4b2d-9b5d-ab8dfbbd4bed'
+uuid.v3('Hello, World!', MY_NAMESPACE); // ⇨ 'e8b5a51d-11c8-3310-a6ab-367563f20686'
 
 ```
 
 Version 5 (namespace):
 
 ```javascript
-const uuidv5 = require('uuid/v5');
+const uuid = require('uuid');
 
 // ... using predefined DNS namespace (for domain names)
-uuidv5('hello.example.com', uuidv5.DNS); // ⇨ 'fdda765f-fc57-5604-a269-52a7df8164ec'
+uuid.v5('hello.example.com', uuid.v5.DNS); // ⇨ 'fdda765f-fc57-5604-a269-52a7df8164ec'
 
 // ... using predefined URL namespace (for, well, URLs)
-uuidv5('http://example.com/hello', uuidv5.URL); // ⇨ '3bbcee75-cecc-5b56-8031-b6641c1ed1f1'
+uuid.v5('http://example.com/hello', uuid.v5.URL); // ⇨ '3bbcee75-cecc-5b56-8031-b6641c1ed1f1'
 
 // ... using a custom namespace
 //
 // Note: Custom namespaces should be a UUID string specific to your application!
 // E.g. the one here was generated using this modules `uuid` CLI.
 const MY_NAMESPACE = '1b671a64-40d5-491e-99b0-da01ff1f3341';
-uuidv5('Hello, World!', MY_NAMESPACE); // ⇨ '630eb68f-e0fa-5ecc-887a-7c7a62614681'
+uuid.v5('Hello, World!', MY_NAMESPACE); // ⇨ '630eb68f-e0fa-5ecc-887a-7c7a62614681'
+
+```
+
+## ECMAScript Modules / ESM
+
+For usage in the browser `uuid` provides support for [ECMAScript
+Modules](https://www.ecma-international.org/ecma-262/6.0/#sec-modules) (ESM) that enable
+tree-shaking for bundlers, like [rollup.js](https://rollupjs.org/guide/en/#tree-shaking)
+([example](./examples/browser-rollup/)) and [webpack](https://webpack.js.org/guides/tree-shaking/)
+([example](./examples/browser-webpack/)).
 
+```javascript
+import {v4 as uuid} from 'uuid';
+uuid(); // ⇨ '1b9d6bcd-bbfd-4b2d-9b5d-ab8dfbbd4bed'
 ```
 
+There is experimental native ESM support for [the browser](./examples/browser-esmodules/) but it
+should not be considered ready for production use and may change or disappear in future releases.
+
 ## API
 
-### Version 1
+### Version 1 (Timestamp + Node)
 
 ```javascript
-const uuidv1 = require('uuid/v1');
+const uuid = require('uuid');
 
 // Incantations
-uuidv1();
-uuidv1(options);
-uuidv1(options, buffer, offset);
+uuid.v1();
+uuid.v1(options);
+uuid.v1(options, buffer, offset);
 ```
 
 Generate and return a RFC4122 v1 (timestamp-based) UUID.
@@ -118,7 +134,7 @@ const v1options = {
   msecs: new Date('2011-11-01').getTime(),
   nsecs: 5678
 };
-uuidv1(v1options); // ⇨ '710b962e-041c-11e1-9234-0123456789ab'
+uuid.v1(v1options); // ⇨ '710b962e-041c-11e1-9234-0123456789ab'
 
 ```
 
@@ -127,31 +143,32 @@ Example: In-place generation of two binary IDs
 ```javascript
 // Generate two ids in an array
 const arr = new Array();
-uuidv1(null, arr, 0);  // ⇨ 
+uuid.v1(null, arr, 0);  // ⇨ 
   // [
-  //    44,  94, 164, 192,  64, 103,
-  //    17, 233, 146,  52, 155,  29,
-  //   235,  77,  59, 125
+  //    44,  94, 164, 192,  64,
+  //   103,  17, 233, 146,  52,
+  //    27, 157, 107, 205, 187,
+  //   253
   // ]
-uuidv1(null, arr, 16); // ⇨ 
+uuid.v1(null, arr, 16); // ⇨ 
   // [
-  //    44, 94, 164, 192,  64, 103, 17, 233,
-  //   146, 52, 155,  29, 235,  77, 59, 125,
-  //    44, 94, 164, 193,  64, 103, 17, 233,
-  //   146, 52, 155,  29, 235,  77, 59, 125
+  //    44, 94, 164, 192,  64, 103,  17, 233,
+  //   146, 52,  27, 157, 107, 205, 187, 253,
+  //    44, 94, 164, 193,  64, 103,  17, 233,
+  //   146, 52,  27, 157, 107, 205, 187, 253
   // ]
 
 ```
 
-### Version 3
+### Version 3 (Namespace)
 
 ```javascript
-const uuidv3 = require('uuid/v3');
+const uuid = require('uuid');
 
 // Incantations
-uuidv3(name, namespace);
-uuidv3(name, namespace, buffer);
-uuidv3(name, namespace, buffer, offset);
+uuid.v3(name, namespace);
+uuid.v3(name, namespace, buffer);
+uuid.v3(name, namespace, buffer, offset);
 ```
 
 Generate and return a RFC4122 v3 UUID.
@@ -166,19 +183,19 @@ Returns `buffer`, if specified, otherwise the string form of the UUID
 Example:
 
 ```javascript
-uuidv3('hello world', MY_NAMESPACE);  // ⇨ '042ffd34-d989-321c-ad06-f60826172424'
+uuid.v3('hello world', MY_NAMESPACE);  // ⇨ '042ffd34-d989-321c-ad06-f60826172424'
 
 ```
 
-### Version 4
+### Version 4 (Random)
 
 ```javascript
-const uuidv4 = require('uuid/v4')
+const uuid = require('uuid');
 
 // Incantations
-uuidv4();
-uuidv4(options);
-uuidv4(options, buffer, offset);
+uuid.v4();
+uuid.v4(options);
+uuid.v4(options, buffer, offset);
 ```
 
 Generate and return a RFC4122 v4 UUID.
@@ -200,22 +217,22 @@ const v4options = {
     0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
   ]
 };
-uuidv4(v4options); // ⇨ '109156be-c4fb-41ea-b1b4-efe1671c5836'
+uuid.v4(v4options); // ⇨ '109156be-c4fb-41ea-b1b4-efe1671c5836'
 
 ```
 
 Example: Generate two IDs in a single buffer
 
 ```javascript
 const buffer = new Array();
-uuidv4(null, buffer, 0);  // ⇨ 
+uuid.v4(null, buffer, 0);  // ⇨ 
   // [
   //   155, 29, 235,  77,  59,
   //   125, 75, 173, 155, 221,
   //    43, 13, 123,  61, 203,
   //   109
   // ]
-uuidv4(null, buffer, 16); // ⇨ 
+uuid.v4(null, buffer, 16); // ⇨ 
   // [
   //   155,  29, 235,  77,  59, 125,  75, 173,
   //   155, 221,  43,  13, 123,  61, 203, 109,
@@ -225,15 +242,15 @@ uuidv4(null, buffer, 16); // ⇨
 
 ```
 
-### Version 5
+### Version 5 (Namespace)
 
 ```javascript
-const uuidv5 = require('uuid/v5');
+const uuid = require('uuid');
 
 // Incantations
-uuidv5(name, namespace);
-uuidv5(name, namespace, buffer);
-uuidv5(name, namespace, buffer, offset);
+uuid.v5(name, namespace);
+uuid.v5(name, namespace, buffer);
+uuid.v5(name, namespace, buffer, offset);
 ```
 
 Generate and return a RFC4122 v5 UUID.
@@ -248,7 +265,7 @@ Returns `buffer`, if specified, otherwise the string form of the UUID
 Example:
 
 ```javascript
-uuidv5('hello world', MY_NAMESPACE);  // ⇨ '9f282611-e0fd-5650-8953-89c8e342da0b'
+uuid.v5('hello world', MY_NAMESPACE);  // ⇨ '9f282611-e0fd-5650-8953-89c8e342da0b'
 
 ```