feat: Migrate the settings field from ESLint configs (#361)

* Add basic support for migrating settings field for oxlint plugins.

* Add an integration test for the settings migration.

* Add special logic for handling the react.version field, as `detect` is commonly used and we should make sure not to output an invalid oxlint config.

* Resolve feedback, remove runtime value from types.ts.

* Resolve feedback, simplify code for skipping unsupported settings keys.

* Update the nextjs config snapshot.

* Simplify deepMerge.

* Simplify the assignment logic further.

* Use type-only imports.

* Update the settings migration to include settings for JS Plugins.

When the `--js-plugins` option is passed, we should migrate all settings (other than import-related settings, as they are not supported by the native plugin).

* Update readme.

* Drop a few unsupported settings keys.

And genericize the code a bit so we can easily add more in the future.

---------

Co-authored-by: Alexander S. <sysix@sysix-coding.de>

Author: connorshea

README.md

@@ -63,9 +63,11 @@ The migration tool has been tested to work quite well for simple ESLint flat con
 
 Here are some known caveats to be aware of:
 
-**`settings` field not migrated**
+**`settings` field migration**
 
-The `settings` field (e.g. for setting the React version) is not migrated to the oxlint config yet. You may need to copy it over manually if you have any settings specified.
+The `settings` field (e.g. for setting the React version) is migrated for known oxlint-supported plugins: `jsx-a11y`, `next`, `react`, `jsdoc`, and `vitest`. By default, other settings keys are skipped since they aren't supported by oxlint. If using the `--js-plugins` flag, other settings keys will also be migrated in order to support JS Plugins.
+
+Note: Oxlint does not support `settings` in override configs. If your ESLint config has settings in configs with `files` patterns, those settings will be skipped and a warning will be shown.
 
 Not all `settings` options are supported by oxlint, and so rule behavior in certain edge-cases may differ. See [the Settings docs](https://oxc.rs/docs/guide/usage/linter/config-file-reference.html#settings) for more info.
 

integration_test/__snapshots__/many-extends.spec.ts.snap

@@ -335,7 +335,11 @@ exports[`many-extends.spec.ts > many-extends.spec.ts 1`] = `
       "react/function-component-definition",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions.",
+    "Settings found in config with 'files' pattern (import/extensions). Oxlint does not support settings in overrides, these settings will be skipped.",
+    "Settings found in config with 'files' pattern (import/extensions, import/external-module-folders, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
+  ],
 }
 `;
 
@@ -674,7 +678,11 @@ exports[`many-extends.spec.ts --js-plugins > many-extends.spec.ts--js-plugins 1`
       "react/function-component-definition",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions.",
+    "Settings found in config with 'files' pattern (import/extensions). Oxlint does not support settings in overrides, these settings will be skipped.",
+    "Settings found in config with 'files' pattern (import/extensions, import/external-module-folders, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
+  ],
 }
 `;
 
@@ -1034,7 +1042,11 @@ exports[`many-extends.spec.ts --type-aware > many-extends.spec.ts--type-aware 1`
       "react/function-component-definition",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions.",
+    "Settings found in config with 'files' pattern (import/extensions). Oxlint does not support settings in overrides, these settings will be skipped.",
+    "Settings found in config with 'files' pattern (import/extensions, import/external-module-folders, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
+  ],
 }
 `;
 
@@ -1328,6 +1340,10 @@ exports[`many-extends.spec.ts merge > many-extends.spec.ts--merge 1`] = `
       "react/function-component-definition",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions.",
+    "Settings found in config with 'files' pattern (import/extensions). Oxlint does not support settings in overrides, these settings will be skipped.",
+    "Settings found in config with 'files' pattern (import/extensions, import/external-module-folders, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
+  ],
 }
 `;

integration_test/__snapshots__/next-core-web-vitals.spec.ts.snap

@@ -137,6 +137,7 @@ exports[`next-core-web-vitals > next-core-web-vitals 1`] = `
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -278,6 +279,7 @@ exports[`next-core-web-vitals --js-plugins > next-core-web-vitals--js-plugins 1`
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -419,6 +421,7 @@ exports[`next-core-web-vitals --type-aware > next-core-web-vitals--type-aware 1`
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -559,6 +562,7 @@ exports[`next-core-web-vitals merge > next-core-web-vitals--merge 1`] = `
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;

integration_test/__snapshots__/next-eslint-config-project.spec.ts.snap

@@ -133,6 +133,7 @@ exports[`next-eslint-config-project > next-eslint-config-project 1`] = `
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -270,6 +271,7 @@ exports[`next-eslint-config-project --js-plugins > next-eslint-config-project--j
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -407,6 +409,7 @@ exports[`next-eslint-config-project --type-aware > next-eslint-config-project--t
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;
@@ -545,6 +548,7 @@ exports[`next-eslint-config-project merge > next-eslint-config-project--merge 1`
   },
   "warnings": [
     "special parser detected: eslint-config-next/parser",
+    "Settings found in config with 'files' pattern (react, import/parsers, import/resolver). Oxlint does not support settings in overrides, these settings will be skipped.",
   ],
 }
 `;

integration_test/__snapshots__/pupeeteer.spec.ts.snap

@@ -283,7 +283,10 @@ exports[`puppeteer > puppeteer 1`] = `
       "@typescript-eslint/consistent-type-exports",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions, import/external-module-folders, import/parsers, import/resolver.",
+    "Settings not migrated (not supported by oxlint): import/resolver.",
+  ],
 }
 `;
 
@@ -600,7 +603,10 @@ exports[`puppeteer --js-plugins > puppeteer--js-plugins 1`] = `
       "@typescript-eslint/consistent-type-exports",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions, import/external-module-folders, import/parsers, import/resolver.",
+    "Settings not migrated (not supported by oxlint): import/resolver.",
+  ],
 }
 `;
 
@@ -907,7 +913,10 @@ exports[`puppeteer --type-aware > puppeteer--type-aware 1`] = `
       "@typescript-eslint/consistent-type-exports",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions, import/external-module-folders, import/parsers, import/resolver.",
+    "Settings not migrated (not supported by oxlint): import/resolver.",
+  ],
 }
 `;
 
@@ -1176,6 +1185,9 @@ exports[`puppeteer merge > puppeteer--merge 1`] = `
       "@typescript-eslint/consistent-type-exports",
     ],
   },
-  "warnings": [],
+  "warnings": [
+    "Settings not migrated (not supported by oxlint): import/extensions, import/external-module-folders, import/parsers, import/resolver.",
+    "Settings not migrated (not supported by oxlint): import/resolver.",
+  ],
 }
 `;