refactor: Add timers polyfill to DHT package for standalone browser usage (#3379)

## Summary

Adds the `timers-browserify` polyfill to the DHT package, enabling
standalone DHT usage in browsers without requiring consumers to manually
polyfill `setImmediate`. The SDK retains its existing polyfill for
redundancy.

## Changes

- Add `timers-browserify` dependency to `@streamr/dht` package
- Add `import 'timers'` polyfill in DHT's `exports.ts` for browser
compatibility
- Configure `timers` → `timers-browserify` alias in DHT's rollup browser
config

Author: mondoreale

CHANGELOG.md

@@ -14,6 +14,8 @@ Changes before Tatum release are not documented in this file.
 
 #### Added
 
+- Add `timers-browserify` polyfill to `@streamr/dht` for standalone browser usage ([#3379])
+
 #### Changed
 
 ### @streamr/sdk
@@ -686,3 +688,4 @@ Autostaker changes:
 [#3368]: https://github.com/streamr-dev/network/pull/3368
 [#3369]: https://github.com/streamr-dev/network/pull/3369
 [#3373]: https://github.com/streamr-dev/network/pull/3373
+[#3379]: https://github.com/streamr-dev/network/pull/3379

package-lock.json

@@ -63,6 +63,7 @@
     "lodash": "^4.17.21",
     "lru-cache": "^11.2.2",
     "node-datachannel": "^0.27.0",
+    "timers-browserify": "^2.0.12",
     "uuid": "^11.1.0",
     "websocket": "^1.0.34",
     "ws": "^8.18.3"

packages/dht/package.json

@@ -21,6 +21,7 @@ const browserAliases: Alias[] = [
             new URL('./dist/browser/src/browser/', import.meta.url)
         ),
     },
+    { find: 'timers', replacement: 'timers-browserify' },
 ]
 
 export default defineConfig([
@@ -54,11 +55,7 @@ function nodejs(): RollupOptions {
                 preferBuiltins: true,
             }),
         ],
-        external: [
-            /node_modules/,
-            /@streamr\//,
-        ],
-
+        external: [/node_modules/, /@streamr\//],
     }
 }
 
@@ -77,11 +74,7 @@ function nodejsTypes(): RollupOptions {
             nodeResolve(),
             dts(),
         ],
-        external: [
-            /node_modules/,
-            /@streamr\//,
-        ],
-
+        external: [/node_modules/, /@streamr\//],
     }
 }
 
@@ -110,19 +103,14 @@ function browser(): RollupOptions {
                 browser: true,
             }),
         ],
-        external: [
-            /node_modules/,
-            /@streamr\//,
-        ],
+        external: [/node_modules/, /@streamr\//],
     }
 }
 
 function browserTypes(): RollupOptions {
     return {
         input: './dist/browser/src/exports.d.ts',
-        output: [
-            { file: './dist/exports-browser.d.ts' },
-        ],
+        output: [{ file: './dist/exports-browser.d.ts' }],
         plugins: [
             alias({
                 entries: browserAliases,
@@ -133,9 +121,6 @@ function browserTypes(): RollupOptions {
             }),
             dts(),
         ],
-        external: [
-            /node_modules/,
-            /@streamr\//,
-        ],
+        external: [/node_modules/, /@streamr\//],
     }
 }

packages/dht/rollup.config.mts

@@ -1,3 +1,9 @@
+/**
+ * Importing 'timers' ensures `setImmediate` is available in browsers,
+ * as it's polyfilled by `timers-browserify`. In Node.js, it's already global.
+ */
+import 'timers'
+
 export { DhtNode, type DhtNodeEvents, type DhtNodeOptions } from './dht/DhtNode'
 export { ListeningRpcCommunicator } from './transport/ListeningRpcCommunicator'
 export { RoutingRpcCommunicator } from './transport/RoutingRpcCommunicator'

packages/dht/src/exports.ts

@@ -3,6 +3,7 @@
  * as it's polyfilled by `timers-browserify`. In Node.js, it's already global.
  */
 import 'timers'
+
 import './setupTsyringe'
 import './utils/PatchTsyringe'