[sean0407]

Fixes #3158

Why

When the browser websocket closes or errors before opening, webSocketOpened never settles. sendMessage() then remains pending and the test runner eventually reports only that browser tests did not start.

Reproduction

Run the web-sockets test with an injected websocket, close the browser-side socket before its open event, then send a wtr-session-started message. Before this change, the regression test timed out because sendMessage() never settled. With the fix, the test receives the websocket connection error immediately.

Changes

• Reject the open wait when the websocket errors or closes before opening, and remove the listeners after either success or failure.
• Add a regression test that runs the served client module and closes a fake websocket before opening.

Checks

• npm run build --workspace=@web/parse5-utils — passed.
• npm run build --workspace=@web/dev-server-core — passed.
• node --experimental-strip-types --test --test-force-exit test/web-sockets/webSocketsPlugin.test.ts from packages/dev-server-core — passed (5 tests).
• Prettier check on both changed files — passed.
• ESLint on both changed files — passed.
• git diff --check — passed.

[changeset-bot]

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Latest commit: 6672f8a

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