chore: eslint v10 upgrade

[AmberFryar]

Description

Upgrade to eslint 10 and make required updates.
...

End to End Test:
(See Pepr Excellent Examples)

Related Issue

Fixes #

Relates to #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Unit, Integration, docs, adr added or updated as needed
• Contributor Guide Steps followed

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	@​typescript-eslint/​parser@​8.45.0 ⏵ 8.56.1
	undici@​7.24.2 ⏵ 7.24.0	+1		+1
	@​commitlint/​cli@​20.4.3 ⏵ 20.4.1	+1			+1
	heredoc@​1.3.1
	@​types/​eslint@​9.6.1
	@​typescript-eslint/​eslint-plugin@​8.45.0 ⏵ 8.56.1	+1		+1
	@​types/​node@​25.4.0 ⏵ 25.2.3				+2
	command-line-args@​6.0.1
	eslint@​9.36.0 ⏵ 10.0.2	+1			-1
	fast-check@​4.6.0 ⏵ 4.5.3	+1			+5
	@​eslint/​js@​9.36.0 ⏵ 10.0.1			+10
	@​semantic-release/​npm@​13.1.5 ⏵ 13.1.4				+3
	@​commitlint/​config-conventional@​20.4.3 ⏵ 20.4.1				+1

View full report

[samayer12]

@greptileai

[greptile-apps]

Greptile Summary

This PR upgrades ESLint from v9 to v10 and migrates all config files from FlatCompat-wrapped configs to native flat config syntax (tsPlugin.configs["flat/recommended"]). It also removes fileURLToPath/__dirname boilerplate in favour of import.meta.dirname, adds { cause } chaining to re-thrown errors in several source files, and pins previously range-versioned devDependencies to exact versions.

Confidence Score: 5/5

Safe to merge; all findings are P2 style suggestions that do not block functionality

The ESLint v10 migration is mechanically correct — FlatCompat removed, flat/recommended adopted, import.meta.dirname substituted for __dirname boilerplate. Source-code linting fixes (cause chaining, const promotion, unused assignment removal) are all valid improvements. The three P2 comments on package.json (engines field accuracy, @types/eslint version, @types/command-line-args version) are housekeeping items that won't break anything at runtime.

package.json — engines field and type package versions deserve a follow-up

Important Files Changed

Filename	Overview
package.json	ESLint 10.0.1 added to dependencies; engines field unchanged at >=20.0.0 despite ESLint 10 requiring ^20.19.0+; @types/command-line-args@5.x alongside command-line-args@6.x
config/eslint.root.config.mjs	Correctly migrated to native flat config using tsPlugin.configs["flat/recommended"] and import.meta.dirname; FlatCompat removed
config/eslint.integration.config.mjs	Cleanly migrated to flat config; tsParser/typescriptEslint explicit registrations removed in favour of flat/recommended
config/eslint.test.config.mjs	Migrated to flat config; correctly dropped path import since import.meta.dirname is now used directly
src/templates/eslint.config.mjs	Template updated to flat/recommended pattern; uses import.meta.dirname consistent with ESLint 10's node requirements
src/lib/controller/migrateStore.ts	Removed redundant reassignment of storeCache after sendUpdatesAndFlushCache; correct since storeCache is unused after that point
src/cli/init/templates.test.ts	Updated test assertion to check for flat/recommended string instead of parser: tsParser — correctly reflects the new config format

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["npm run format:*"] --> B["eslint CLI v10"]
    B --> C{Config target}
    C -->|src/**| D["eslint.root.config.mjs"]
    C -->|src/**/*.test.ts| E["eslint.test.config.mjs"]
    C -->|integration/**| F["eslint.integration.config.mjs"]
    D --> G["js.configs.recommended"]
    D --> H["tsPlugin.configs['flat/recommended']"]
    D --> I["Custom rules\n(no-floating-promises, etc.)"]
    E --> G
    E --> H
    E --> J["Test-specific rules\n(max-nested-callbacks: 8)"]
    F --> G
    F --> H
    F --> K["Integration rules\n(complexity, max-depth, etc.)"]
    H --> L["@typescript-eslint/parser\nauto-registered"]
    M["src/templates/eslint.config.mjs\n(generated into user projects)"] -->|same flat/recommended pattern| H

Loading

Comments Outside Diff (1)

1. package.json, line 9-11 (link)

   engines field not updated for ESLint 10

   ESLint 10 (@eslint/core, @eslint/config-array, @eslint/js) requires "node": "^20.19.0 || ^22.13.0 || >=24", but the engines field still declares >=20.0.0. Any user (or CI runner) on Node 20.0.0–20.18.x will get an engines mismatch warning from npm and ESLint will fail to execute. The generated template (src/templates/eslint.config.mjs) also uses import.meta.dirname, which was only added in Node 20.11.0, compounding the risk for end-users of the scaffold.

_{Reviews (1): Last reviewed commit: "chore: update deps" | Re-trigger Greptile}

[greptile-apps]

@types/eslint@9.6.1 may conflict with ESLint 10's bundled types

ESLint 10 was rewritten in TypeScript and ships its own type definitions. @types/eslint@9.6.1 is the DefinitelyTyped community package targeting the ESLint 9 API surface. Having both on the resolution path can cause duplicate/conflicting type declarations. Consider either removing @types/eslint entirely (relying on ESLint 10's own types) or checking whether a @types/eslint@10.x exists before keeping this entry.

[greptile-apps]

@types/command-line-args@5.x types for a command-line-args@6.x runtime

command-line-args was bumped to 6.0.1 in dependencies (new direct dep in this PR), but @types/command-line-args remains at 5.2.3 in devDependencies. A major version bump typically means breaking API changes; if the 6.x API surface diverged from the 5.x types, TypeScript will silently accept incorrect call signatures. Consider updating @types/command-line-args to a version that targets v6, or verifying the API is identical.