# Breaking changes in v20 This release bumps `@open-turo/eslint-config-typescript` to v20.x. The following breaking changes cascade from that dependency (newest first). ## v20.1.0 - Perfectionist Rule Overrides (2026-03-09) - `perfectionist/sort-classes`: Uses explicit groups for class member ordering instead of alphabetical. - `perfectionist/sort-switch-case` and `perfectionist/sort-union-types`: Changed from alphabetical to natural sort order. ```diff diff --git a/test/__snapshots__/test.spec.js.snap b/test/__snapshots__/test.spec.js.snap --- a/test/__snapshots__/test.spec.js.snap +++ b/test/__snapshots__/test.spec.js.snap @@ -1359,8 +1359,84 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "perfectionist/sort-classes": [ 2, { - "order": "asc", - "type": "alphabetical", + "groups": [ + "index-signature", + [ + "static-property", + "static-accessor-property", + ], + [ + "static-get-method", + "static-set-method", + ], + [ + "protected-static-property", + "protected-static-accessor-property", + ], + [ + "protected-static-get-method", + "protected-static-set-method", + ], + [ + "private-static-property", + "private-static-accessor-property", + ], + [ + "private-static-get-method", + "private-static-set-method", + ], + "static-block", + [ + "property", + "accessor-property", + ], + [ + "protected-property", + "protected-accessor-property", + ], + [ + "private-property", + "private-accessor-property", + ], + "constructor", + [ + "get-method", + "set-method", + ], + [ + "protected-get-method", + "protected-set-method", + ], + [ + "private-get-method", + "private-set-method", + ], + [ + "static-method", + "static-function-property", + ], + [ + "protected-static-method", + "protected-static-function-property", + ], + [ + "private-static-method", + "private-static-function-property", + ], + [ + "method", + "function-property", + ], + [ + "protected-method", + "protected-function-property", + ], + [ + "private-method", + "private-function-property", + ], + "unknown", + ], }, ], @@ -1471,15 +1471,13 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "perfectionist/sort-switch-case": [ 2, { - "order": "asc", - "type": "alphabetical", + "type": "natural", }, ], "perfectionist/sort-union-types": [ 2, { - "order": "asc", - "type": "alphabetical", + "type": "natural", }, ], ``` (Similar changes apply to index.mjs and legacy recommended config.) ## v20.0.0 - Strict Type-Checked and Legacy Config Parity (2026-03-06) - Flat config now enforces `strictTypeChecked` instead of `recommendedTypeChecked`, enabling additional @typescript-eslint rules that may raise new errors. - eslint/recommended v9 rule changes backported to legacy config — rules previously off are now errors (constructor-super, getter-return, no-dupe-\*, no-undef, no-unused-vars, etc.). - Some unicorn rules disabled: empty-brace-spaces, no-nested-ternary, number-literal-case, template-indent. ```diff diff --git a/test/__snapshots__/test.spec.js.snap b/test/__snapshots__/test.spec.js.snap --- a/test/__snapshots__/test.spec.js.snap +++ b/test/__snapshots__/test.spec.js.snap @@ -553,6 +553,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` ], "@typescript-eslint/ban-ts-comment": [ 2, + { + "minimumDescriptionLength": 10, + }, ], @@ -619,6 +622,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "@typescript-eslint/no-duplicate-type-constituents": [ 2, ], + "@typescript-eslint/no-dynamic-delete": [ + 2, + ], @@ -646,18 +655,36 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "@typescript-eslint/no-import-type-side-effects": [ 2, ], + "@typescript-eslint/no-invalid-void-type": [ + 2, + ], + "@typescript-eslint/no-meaningless-void-operator": [ + 2, + ], "@typescript-eslint/no-misused-new": [ 2, ], "@typescript-eslint/no-misused-promises": [ 2, ], + "@typescript-eslint/no-misused-spread": [ + 2, + ], + "@typescript-eslint/no-mixed-enums": [ + 2, + ], @@ -673,6 +700,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "@typescript-eslint/no-unnecessary-condition": [ 0, ], + "@typescript-eslint/no-unnecessary-template-expression": [ + 2, + ], @@ -738,26 +777,57 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "@typescript-eslint/prefer-as-const": [ 2, ], + "@typescript-eslint/prefer-literal-enum-member": [ + 2, + ], "@typescript-eslint/prefer-namespace-keyword": [ 2, ], "@typescript-eslint/prefer-promise-reject-errors": [ 2, ], + "@typescript-eslint/prefer-reduce-type-parameter": [ + 2, + ], + "@typescript-eslint/prefer-return-this-type": [ + 2, + ], @@ -780,6 +850,12 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "@typescript-eslint/unbound-method": [ 2, ], + "@typescript-eslint/unified-signatures": [ + 2, + ], + "@typescript-eslint/use-unknown-in-catch-callback-variable": [ + 2, + ], @@ -1222,6 +1298,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "no-reserved-keys": [ 0, ], + "no-return-await": [ + 0, + ], @@ -1310,6 +1389,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "no-useless-catch": [ 2, ], + "no-useless-constructor": [ + 0, + ], @@ -7049,7 +7361,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "off", ], "constructor-super": [ - "off", + 2, ], @@ -7112,7 +7424,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "off", ], "getter-return": [ - "off", + 2, ], @@ -7591,7 +7903,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` 0, ], "no-const-assign": [ - "off", + 2, ], @@ -7714,7 +8026,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "error", ], "no-redeclare": [ - "off", + 2, ], @@ -7756,19 +8068,19 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "off", ], "no-undef": [ - "off", + 2, ], @@ -7783,7 +8095,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "error", ], "no-unused-vars": [ - "off", + 2, ], @@ -7804,7 +8116,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "off", ], "no-with": [ - "off", + 2, ], @@ -9108,7 +9494,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "off", ], "unicorn/empty-brace-spaces": [ - "error", + 0, ], @@ -9201,7 +9587,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "error", ], "unicorn/no-nested-ternary": [ - "error", + 0, ], @@ -9270,7 +9656,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "error", ], "unicorn/number-literal-case": [ - "error", + 0, ], @@ -9459,7 +9845,7 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "error", ], "unicorn/template-indent": [ - "error", + 0, ], ``` (Similar @typescript-eslint changes apply to index.mjs. Additional legacy rules changed from "off" to error: no-class-assign, no-dupe-args, no-dupe-class-members, no-dupe-keys, no-func-assign, no-import-assign, no-new-native-nonconstructor, no-obj-calls, no-setter-return, no-this-before-super, no-unreachable, no-unsafe-negation.) ## eslint-plugin-sonarjs v3 → v4 - `eslint-plugin-sonarjs` upgrade from v3 to v4 results in a corresponding major version change due to configuration changes. As codified in snapshots: ```diff diff --git a/test/__snapshots__/test.spec.js.snap b/test/__snapshots__/test.spec.js.snap index d404760..032574e 100644 --- a/test/__snapshots__/test.spec.js.snap +++ b/test/__snapshots__/test.spec.js.snap @@ -1702,9 +1702,6 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "sonarjs/class-prototype": [ 0, ], - "sonarjs/code-eval": [ - 2, - ], "sonarjs/cognitive-complexity": [ 2, 15, @@ -1802,10 +1799,6 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "sonarjs/encryption-secure-mode": [ 2, ], - "sonarjs/enforce-trailing-comma": [ - 0, - "always-multiline", - ], "sonarjs/existing-groups": [ 2, ], @@ -2220,6 +2213,9 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "sonarjs/no-selector-parameter": [ 2, ], + "sonarjs/no-session-cookies-on-static-assets": [ + 2, + ], "sonarjs/no-skipped-tests": [ 2, ], @@ -2424,9 +2420,6 @@ exports[`validate config the flat config is correct for index.cjs 1`] = ` "sonarjs/strings-comparison": [ 0, ], - "sonarjs/super-invocation": [ - 2, - ], "sonarjs/table-header": [ 2, ], @@ -4785,9 +4778,6 @@ exports[`validate config the flat config is correct for index.mjs 1`] = ` "sonarjs/class-prototype": [ 0, ], - "sonarjs/code-eval": [ - 2, - ], "sonarjs/cognitive-complexity": [ 2, 15, @@ -4885,10 +4875,6 @@ exports[`validate config the flat config is correct for index.mjs 1`] = ` "sonarjs/encryption-secure-mode": [ 2, ], - "sonarjs/enforce-trailing-comma": [ - 0, - "always-multiline", - ], "sonarjs/existing-groups": [ 2, ], @@ -5303,6 +5289,9 @@ exports[`validate config the flat config is correct for index.mjs 1`] = ` "sonarjs/no-selector-parameter": [ 2, ], + "sonarjs/no-session-cookies-on-static-assets": [ + 2, + ], "sonarjs/no-skipped-tests": [ 2, ], @@ -5507,9 +5496,6 @@ exports[`validate config the flat config is correct for index.mjs 1`] = ` "sonarjs/strings-comparison": [ 0, ], - "sonarjs/super-invocation": [ - 2, - ], "sonarjs/table-header": [ 2, ], @@ -8329,9 +8315,6 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "sonarjs/class-prototype": [ "off", ], - "sonarjs/code-eval": [ - "error", - ], "sonarjs/cognitive-complexity": [ "error", ], @@ -8416,9 +8399,6 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "sonarjs/encryption-secure-mode": [ "error", ], - "sonarjs/enforce-trailing-comma": [ - "off", - ], "sonarjs/existing-groups": [ "error", ], @@ -8782,6 +8762,9 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "sonarjs/no-selector-parameter": [ "error", ], + "sonarjs/no-session-cookies-on-static-assets": [ + "error", + ], "sonarjs/no-skipped-tests": [ "error", ], @@ -8983,9 +8966,6 @@ exports[`validate config the legacy recommended config is correct 1`] = ` "sonarjs/strings-comparison": [ "off", ], - "sonarjs/super-invocation": [ - "error", - ], "sonarjs/table-header": [ "error", ], ```