[jennifer-shehane]

• Closes N/A — this is the next slice of the ESLint 9 flat-config migration tracked in guides/eslint-migration.md.

Additional details

This moves @packages/net-stubbing, @packages/network, @packages/network-tools and @packages/socket onto the shared flat config (@packages/eslint-config, ESLint 9), following the guide and the earlier batches (#35146, #35148).

Per package

• Added eslint.config.ts that spreads baseConfig then jsonConfig, with tsconfigRootDir: __dirname.
• package.json: added the @packages/eslint-config, eslint and jiti devDependencies, set lint to eslint and added the lint-staged key. The first --fix with jsonConfig reordered the top-level keys, as the guide expects.
• Deleted .eslintignore and the nested test/.eslintrc.json files. There wasn't much to port: baseConfig already covers the test globals, and the old ignore paths either no longer exist or are handled centrally.
• Added the four packages to the root lint:fix scope and ticked them off in the guide. network-tools wasn't in the checklist yet, so I added it.

Package-specific overrides

• All four turn no-restricted-properties and no-restricted-syntax off for test/**. This carries over the root .eslintrc.js exemption for **/test/**, the same way config and scaffold-config do, so specs can still use sync fs and process.geteuid().
• socket ignores browser/**, the output of tsconfig.browser.json, which the shared config's build-output ignores don't cover.
• net-stubbing ignores lib/**/*.js, because build-prod compiles in place. For the same reason its tsconfig.json include drops the root *.ts glob. Otherwise build-prod would emit an eslint.config.js, and ESLint 9 would pick that up over the .ts config.

ban-ts-comment (33 sites)

• Every @ts-ignore that still hides a real error is now // @ts-expect-error - <reason>, and each reason names the actual compiler error.
• Five @ts-ignores no longer suppressed anything, so I deleted them: two in network's agent.ts, one in its spec, one in network-tools' cors.ts and one in socket's utils.ts.
• Where an easy fix was available, I typed the code instead of suppressing the error:
  • socket's circular test objects, plus Packet-typed test packets
  • vi.stubGlobal('window', {})
  • a typed new Promise in network's agent.spec.ts
• allowDestroy (network) now adds destroy with Object.assign and is generic, so callers get back their own server type plus destroy instead of a plain net.Server. Runtime behavior is unchanged. It has callers in server, https-proxy and proxy, and all of them still type-check.
• The import-x/namespace error on socket's hasBinary is handled with a narrowed type and a "Safe because" comment. The export comes from our own patches/socket.io-parser+4.2.6.patch, which doesn't touch the type declarations.

prefer-const

• develop turned on prefer-const in the shared config (chore: enable prefer-const in the shared ESLint flat config #35169) while this PR was open. Merging it surfaced 18 violations in net-stubbing and network. eslint --fix turned 17 never-reassigned lets into consts. The last one, in net-stubbing's driver-events.ts, destructured a reassigned value together with a never-reassigned type, so I split it into a const and a let.

Intentionally left alone

• The tslint scripts stay, matching how launcher, proxy and network-interception were migrated.

All four packages lint with 0 errors and 0 warnings.

Steps to test

yarn lint --scope '@packages/{net-stubbing,network,network-tools,socket}'
yarn check-ts --scope '@packages/{net-stubbing,network,network-tools,socket}'
yarn health-check
yarn workspace @packages/net-stubbing test
yarn workspace @packages/network-tools test-unit
yarn workspace @packages/socket test-unit
yarn workspace @packages/network test-unit

All of these pass locally on the branch with the latest develop merged in. One exception is @packages/network, which has 54 failures in an unprivileged container. Those are port and proxy errors from the environment, and I compared the run against develop: the failing set is identical, with no new failures. I also ran check-ts for server, https-proxy and proxy because of the allowDestroy type change, along with https-proxy's tests (24/24).

How has the user experience changed?

No change. This is lint configuration plus type-only edits.

PR Tasks

• [na] Is there an associated issue with maintainer approval for PR submission? Mechanical change, part of the tracked ESLint migration.
• Have tests been added/updated? The spec files were updated to replace suppressions with types. Behavior is unchanged.
• [na] Has a PR for user-facing changes been opened in cypress-documentation?
• [na] Have API changes been updated in the type definitions?

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Generated by Claude Code

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Note

Low Risk
Tooling and type-only edits in network-related packages; no intended runtime behavior changes beyond lint compliance.

Overview
Moves @packages/net-stubbing, @packages/network, @packages/network-tools, and @packages/socket onto the shared @packages/eslint-config flat config (ESLint 9): new eslint.config.ts files, lint-staged, updated lint scripts, removal of legacy .eslintignore / test/.eslintrc.json, and inclusion in the root lint:fix scope. The migration guide marks these packages (and network-tools) complete.

Package-specific lint ignores: net-stubbing skips in-place lib/**/*.js build output and tightens tsconfig.json so eslint.config.ts is not emitted beside sources; socket ignores browser/** from build:browser.

Lint and ban-ts-comment cleanup across the four packages: @ts-ignore → documented @ts-expect-error, removal of stale suppressions, stronger test typings, and small formatting fixes. allowDestroy in @packages/network now attaches destroy via Object.assign with a generic return type (runtime behavior unchanged; callers in server/https-proxy/proxy still type-check).

^{Reviewed by Cursor Bugbot for commit 6a38528. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cypress]

cypress    Run #75020

Run Properties:   Passed #75020  •  011ecae645: chore: keep specs exempt from the restricted-API rules

Project	cypress
Branch Review	eslint/r9-network-socket
Run status	Passed #75020
Run duration	15m 39s
Commit	011ecae645: chore: keep specs exempt from the restricted-API rules
Committer	Claude
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	13
Pending	1036
Skipped	0
Passing	30094
View all changes introduced in this branch ↗︎

UI Coverage  67.12%
Untested elements	24
Tested elements	49

Accessibility  98.98%
Failed rules	0 critical   3 serious   2 moderate   0 minor
Failed elements	18

New commits pushed (auto-approval was for 6a38528, head is now eca718b). Auto-approval dismissed pending Cursor Bugbot re-review of the new head SHA.

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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New commits pushed (auto-approval was for eca718b, head is now 011ecae). Auto-approval dismissed pending Cursor Bugbot re-review of the new head SHA.