Eeslint

eslint/v9-to-v10-config

Remove legacy env vars and CLI flags for ESLint v10

transformationmigrationeslintv9v10
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@eslint/v9-to-v10-config

Remove legacy env vars and CLI flags for ESLint v10.

Overview

ESLint v10 removes several configuration mechanisms that were deprecated in v9.

What This Codemod Does

Transform — Remove legacy env vars and CLI flags

ESLINT_USE_FLAT_CONFIG and several ESLINT_FLAGS values are removed in v10. Legacy CLI flags are also removed.

BeforeAfter
ESLINT_USE_FLAT_CONFIG=true eslint .eslint .
ESLINT_USE_FLAT_CONFIG=false eslint .eslint .
v10_config_lookup_from_file in ESLINT_FLAGSRemoved
unstable_config_lookup_from_file in ESLINT_FLAGSRemoved
unstable_ts_config in ESLINT_FLAGSRemoved
--no-eslintrcRemoved
--envRemoved
--rulesdirRemoved
--ignore-pathRemoved
--resolve-plugins-relative-toRemoved

Manual step required — eslint-env inline comments

ESLint v10 reports /* eslint-env */ comments as lint errors. This codemod does not remove them automatically because these comments also declare globals (e.g. /* eslint-env browser */ provides window, document, etc.). Removing them without migrating the globals would silently break rules like no-unused-vars.

After running this codemod, fix eslint-env comments manually:

  1. Remove the /* eslint-env ... */ comment from the source file.
  2. Add the corresponding globals to eslint.config.js:
js

See the globals package for the full list of available environments.

Usage

bash

Or with the workflow runner:

bash

Resources

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