lib: add EventSource Client

PR-URL: #51575
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Matthew Aitken <maitken033380023@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: Uzlopak

.eslintrc.js

@@ -348,6 +348,7 @@ module.exports = {
 Crypto: 'readable',
 CryptoKey: 'readable',
 DecompressionStream: 'readable',
+EventSource: 'readable',
 fetch: 'readable',
 FormData: 'readable',
 ReadableStream: 'readable',

doc/api/cli.md

@@ -898,6 +898,14 @@ CommonJS. This includes the following:
 * Lexical redeclarations of the CommonJS wrapper variables (`require`, `module`,
 `exports`, `__dirname`, `__filename`).
 
+### `--experimental-eventsource`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable exposition of [EventSource Web API][] on the global scope.
+
 ### `--experimental-import-meta-resolve`
 
 <!-- YAML
@@ -2697,6 +2705,7 @@ one is included in the list below.
 *`--experimental-abortcontroller`
 *`--experimental-default-type`
 *`--experimental-detect-module`
+*`--experimental-eventsource`
 *`--experimental-import-meta-resolve`
 *`--experimental-json-modules`
 *`--experimental-loader`
@@ -3172,6 +3181,7 @@ done
 [CustomEvent Web API]: https://dom.spec.whatwg.org/#customevent
 [DEP0025 warning]: deprecations.md#dep0025-requirenodesys
 [ECMAScript module]: esm.md#modules-ecmascript-modules
+[EventSource Web API]: https://html.spec.whatwg.org/multipage/server-sent-events.html#server-sent-events
 [ExperimentalWarning: `vm.measureMemory` is an experimental feature]: vm.md#vmmeasurememoryoptions
 [Fetch API]: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API
 [File System Permissions]: permissions.md#file-system-permissions

doc/node.1

@@ -191,6 +191,9 @@ Use this flag to enable ShadowRealm support.
 .ItFl-experimental-test-coverage
 Enable code coverage in the test runner.
 .
+.ItFl-experimental-eventsource
+Enable experimental support for the EventSource Web API.
+.
 .ItFl-experimental-websocket
 Enable experimental support for the WebSocket API.
 .

lib/.eslintrc.yaml

@@ -152,6 +152,8 @@ rules:
 message: Use `const { Crypto } = require('internal/crypto/webcrypto');` instead of the global.
  - name: CryptoKey
 message: Use `const { CryptoKey } = require('internal/crypto/webcrypto');` instead of the global.
+ - name: EventSource
+message: Use `const { EventSource } = require('internal/deps/undici/undici');` instead of the global.
  - name: fetch
 message: Use `const { fetch } = require('internal/deps/undici/undici');` instead of the global.
  - name: global

lib/internal/bootstrap/web/exposed-window-or-worker.js

@@ -81,6 +81,9 @@ exposeLazyInterfaces(globalThis, 'internal/deps/undici/undici', [
 'FormData','Headers','Request','Response',
 ]);
 
+// https://html.spec.whatwg.org/multipage/server-sent-events.html#server-sent-events.org/
+exposeLazyInterfaces(globalThis,'internal/deps/undici/undici',['EventSource']);
+
 // The WebAssembly Web API which relies on Response.
 // https:// webassembly.github.io/spec/web-api/#streaming-modules
 internalBinding('wasm_web_api').setImplementation((streamState,source)=>{

lib/internal/process/pre_execution.js

@@ -109,6 +109,7 @@ function prepareExecution(options) {
 setupUndici();
 setupWebCrypto();
 setupCustomEvent();
+setupEventsource();
 setupCodeCoverage();
 setupDebugEnv();
 // Process initial diagnostic reporting configuration, if present.
@@ -328,6 +329,13 @@ function setupUndici() {
 }
 }
 
+// https://html.spec.whatwg.org/multipage/server-sent-events.html
+functionsetupEventsource(){
+if(!getOptionValue('--experimental-eventsource')){
+deleteglobalThis.EventSource;
+}
+}
+
 // TODO(aduh95): move this to internal/bootstrap/web/* when the CLI flag is
 // removed.
 functionsetupWebCrypto(){

src/node_options.cc

@@ -406,6 +406,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::enable_source_maps,
 kAllowedInEnvvar);
 AddOption("--experimental-abortcontroller", "", NoOp{}, kAllowedInEnvvar);
+AddOption("--experimental-eventsource",
+"experimental EventSource API",
+ &EnvironmentOptions::experimental_eventsource,
+kAllowedInEnvvar,
+false);
 AddOption("--experimental-fetch",
 "experimental Fetch API",
  &EnvironmentOptions::experimental_fetch,

src/node_options.h

@@ -115,6 +115,7 @@ class EnvironmentOptions : public Options {
 bool require_module = false;
  std::string dns_result_order;
 bool enable_source_maps = false;
+bool experimental_eventsource = false;
 bool experimental_fetch = true;
 bool experimental_websocket = false;
 bool experimental_global_customevent = true;

test/common/globals.js

@@ -124,6 +124,7 @@ const webIdlExposedWindow = new Set([
 'Request',
 'Response',
 'WebSocket',
+'EventSource',
 ]);
 
 constnodeGlobals=newSet([

test/common/index.js

@@ -330,6 +330,10 @@ if (global.structuredClone) {
 knownGlobals.push(global.structuredClone);
 }
 
+if(global.EventSource){
+knownGlobals.push(EventSource);
+}
+
 if(global.fetch){
 knownGlobals.push(fetch);
 }