bunfig.toml

# The final config (user, 2026-10-17): bunfig.answered.toml with Q12-Q14 applied. PR A ships it as the root bunfig.toml.
# Q12: the 24 type-aware rules at Bun's severities (8 errors, the rest warnings), with the five no-unsafe-*, require-await and
# await-thenable off in tests (the override below). Q13: core no-useless-escape stays on (Bun's default). Q14: no [install] peer = false.
[lint]
typeAware = true # Q11: the type-aware rules run in the gate, the editor and every bun lint
plugins = [{ name = "regexp", specifier = "eslint-plugin-regexp" }]
ignorePatterns = [
  "**/dist/**",
  "**/dts/**",
  "docs/**",
  "benchmarks/results/**",
  "**/bench/**/results/**",
]
reportUnusedDisableDirectives = "warn"

[lint.rules]
"@typescript-eslint/ban-ts-comment" = [
  "error",
  { ts-expect-error = "allow-with-description" },
]
"@typescript-eslint/ban-types" = "off"
"@typescript-eslint/consistent-type-definitions" = ["error", "interface"]
"@typescript-eslint/consistent-type-imports" = [
  "error",
  { disallowTypeAnnotations = false, fixStyle = "separate-type-imports", prefer = "type-imports" },
]
"@typescript-eslint/explicit-function-return-type" = "off"
"@typescript-eslint/explicit-module-boundary-types" = "off"
"@typescript-eslint/method-signature-style" = ["error", "property"]
"@typescript-eslint/no-array-constructor" = "error"
"@typescript-eslint/no-dupe-class-members" = "error"
"@typescript-eslint/no-duplicate-enum-values" = "error"
"@typescript-eslint/no-dynamic-delete" = "off"
"@typescript-eslint/no-empty-object-type" = [
  "error",
  { allowInterfaces = "always" },
]
"@typescript-eslint/no-explicit-any" = "off"
"@typescript-eslint/no-extra-non-null-assertion" = "error"
"@typescript-eslint/no-extraneous-class" = "off"
"@typescript-eslint/no-import-type-side-effects" = "error"
"@typescript-eslint/no-invalid-void-type" = "off"
"@typescript-eslint/no-misused-new" = "error"
"@typescript-eslint/no-namespace" = ["error", { allowDeclarations = false }]
"@typescript-eslint/no-non-null-asserted-nullish-coalescing" = "error"
"@typescript-eslint/no-non-null-asserted-optional-chain" = "error"
"@typescript-eslint/no-non-null-assertion" = "off"
"@typescript-eslint/no-redeclare" = ["error", { builtinGlobals = false }]
"@typescript-eslint/no-require-imports" = "error"
"@typescript-eslint/no-this-alias" = "error"
"@typescript-eslint/no-unnecessary-type-constraint" = "error"
"@typescript-eslint/no-unsafe-declaration-merging" = "error"
"@typescript-eslint/no-unsafe-function-type" = "error"
"@typescript-eslint/no-unused-expressions" = [
  "error",
  { allowShortCircuit = true, allowTaggedTemplates = true, allowTernary = true },
]
"@typescript-eslint/no-unused-vars" = [
  "error",
  { args = "after-used", argsIgnorePattern = "^_", caughtErrorsIgnorePattern = "^_", ignoreRestSiblings = true, vars = "all", varsIgnorePattern = "^_" },
]
"@typescript-eslint/no-use-before-define" = [
  "error",
  { classes = false, functions = false, variables = true },
]
"@typescript-eslint/no-useless-constructor" = "off"
"@typescript-eslint/no-wrapper-object-types" = "error"
"@typescript-eslint/prefer-as-const" = "error"
"@typescript-eslint/prefer-literal-enum-member" = "error"
"@typescript-eslint/prefer-namespace-keyword" = "error"
"@typescript-eslint/triple-slash-reference" = "off"
"@typescript-eslint/unified-signatures" = "off"
"accessor-pairs" = [
  "error",
  { enforceForTSTypes = false, enforceForClassMembers = true, getWithoutSet = false, setWithoutGet = true },
]
"array-callback-return" = [
  "error",
  { allowImplicit = false, checkForEach = false, allowVoid = false },
]
"arrow-body-style" = "off"
"block-scoped-var" = "error"
"bun/format" = "off" # Q6: bun fmt --check is its own step
"constructor-super" = "off"
"curly" = "off"
"default-case-last" = "error"
"dot-notation" = ["error", { allowKeywords = true, allowPattern = "" }]
"eqeqeq" = ["error", "smart"]
"getter-return" = "off"
"import/consistent-type-specifier-style" = ["error", "prefer-top-level"]
"import/first" = "error"
"import/newline-after-import" = ["error", { count = 1 }]
"import/no-duplicates" = "error"
"import/no-mutable-exports" = "error"
"import/no-named-default" = "error"
"n/handle-callback-err" = ["error", "^(err|error)$"]
"n/no-exports-assign" = "error"
"n/no-new-require" = "error"
"n/no-path-concat" = "error"
"n/no-top-level-await" = "error"
"new-cap" = [
  "error",
  { capIsNew = false, capIsNewExceptions = ["Array", "Boolean", "Date", "Error", "Function", "Number", "Object", "RegExp", "String", "Symbol", "BigInt"], newIsCap = true, newIsCapExceptions = [], properties = true },
]
"no-alert" = "error"
"no-array-constructor" = "off"
"no-async-promise-executor" = "off"
"no-caller" = "error"
"no-case-declarations" = "error"
"no-class-assign" = "off"
"no-compare-neg-zero" = "error"
"no-cond-assign" = ["error", "always"]
"no-console" = ["warn", {}]
"no-const-assign" = "off"
"no-control-regex" = "error"
"no-debugger" = "error"
"no-delete-var" = "error"
"no-dupe-args" = "off"
"no-dupe-class-members" = "off"
"no-dupe-keys" = "off"
"no-duplicate-case" = "error"
"no-empty" = ["error", { allowEmptyCatch = true }]
"no-empty-character-class" = "off"
"no-empty-pattern" = ["error", { allowObjectPatternsAsParameters = false }]
"no-eval" = ["error", { allowIndirect = false }]
"no-ex-assign" = "error"
"no-extend-native" = ["error", { exceptions = [] }]
"no-extra-bind" = "error"
"no-extra-boolean-cast" = ["error", {}]
"no-fallthrough" = [
  "error",
  { allowEmptyCase = false, reportUnusedFallthroughComment = false },
]
"no-func-assign" = "off"
"no-global-assign" = ["error", { exceptions = [] }]
"no-implied-eval" = "error"
"no-import-assign" = "off"
"no-invalid-regexp" = "off"
"no-irregular-whitespace" = [
  "error",
  { skipComments = false, skipJSXText = false, skipRegExps = false, skipStrings = true, skipTemplates = false },
]
"no-iterator" = "error"
"no-labels" = "off"
"no-lone-blocks" = "error"
"no-loss-of-precision" = "error"
"no-misleading-character-class" = ["error", { allowEscape = false }]
"no-multi-str" = "error"
"no-new" = "error"
"no-new-func" = "error"
"no-new-native-nonconstructor" = "off"
"no-new-symbol" = "off"
"no-new-wrappers" = "error"
"no-obj-calls" = "off"
"no-octal" = "error"
"no-octal-escape" = "error"
"no-proto" = "error"
"no-prototype-builtins" = "error"
"no-redeclare" = "off"
"no-regex-spaces" = "error"
"no-restricted-globals" = [
  "error",
  { message = "Use `globalThis` instead.", name = "global" },
  { message = "Use `globalThis` instead.", name = "self" },
  { message = "Import it: `import { Buffer } from \"node:buffer\"`.", name = "Buffer" },
  { message = "Import it: `import process from \"node:process\"`.", name = "process" },
] # Q8: node/prefer-global/{buffer,process} "never"
"no-restricted-properties" = [
  "error",
  { message = "Use `Object.getPrototypeOf` or `Object.setPrototypeOf` instead.", property = "__proto__" },
  { message = "Use `Object.defineProperty` instead.", property = "__defineGetter__" },
  { message = "Use `Object.defineProperty` instead.", property = "__defineSetter__" },
  { message = "Use `Object.getOwnPropertyDescriptor` instead.", property = "__lookupGetter__" },
  { message = "Use `Object.getOwnPropertyDescriptor` instead.", property = "__lookupSetter__" },
]
"no-restricted-syntax" = "off"
"no-self-assign" = ["error", { props = true }]
"no-self-compare" = "error"
"no-sequences" = ["error", { allowInParentheses = true }]
"no-setter-return" = "off"
"no-shadow-restricted-names" = ["error", { reportGlobalThis = true }]
"no-sparse-arrays" = "error"
"no-template-curly-in-string" = "error"
"no-this-before-super" = "off"
"no-throw-literal" = "error"
"no-undef" = "off"
"no-undef-init" = "error"
"no-unexpected-multiline" = "off"
"no-unmodified-loop-condition" = "error"
"no-unneeded-ternary" = ["error", { defaultAssignment = false }]
"no-unreachable" = "off"
"no-unreachable-loop" = ["error", { ignore = [] }]
"no-unsafe-finally" = "error"
"no-unsafe-negation" = "off"
"no-unused-expressions" = "off"
"no-unused-vars" = "off"
"no-use-before-define" = "off"
"no-useless-backreference" = "off"
"no-useless-call" = "error"
"no-useless-catch" = "error"
"no-useless-computed-key" = ["error", { enforceForClassMembers = true }]
"no-useless-constructor" = "off"
"no-useless-rename" = [
  "error",
  { ignoreDestructuring = false, ignoreImport = false, ignoreExport = false },
]
"no-useless-return" = "error"
"no-var" = "error"
"no-with" = "off"
"object-shorthand" = [
  "error",
  "always",
  { avoidQuotes = true, ignoreConstructors = false },
]
"one-var" = ["error", { initialized = "never" }]
"prefer-arrow-callback" = "off"
"prefer-const" = [
  "error",
  { destructuring = "all", ignoreReadBeforeAssign = true },
]
"prefer-exponentiation-operator" = "error"
"prefer-object-has-own" = "error"
"prefer-promise-reject-errors" = ["error", { allowEmptyReject = false }]
"prefer-regex-literals" = ["error", { disallowRedundantWrapping = true }]
"prefer-rest-params" = "error"
"prefer-spread" = "error"
"prefer-template" = "error"
"react/jsx-child-element-spacing" = "off"
"react/jsx-closing-bracket-location" = "off"
"react/jsx-closing-tag-location" = "off"
"react/jsx-curly-brace-presence" = [
  "error",
  { props = "never", children = "never", propElementValues = "always" },
]
"react/jsx-curly-newline" = "off"
"react/jsx-curly-spacing" = "off"
"react/jsx-equals-spacing" = "off"
"react/jsx-first-prop-new-line" = "off"
"react/jsx-indent" = "off"
"react/jsx-indent-props" = "off"
"react/jsx-max-props-per-line" = "off"
"react/jsx-newline" = "off"
"react/jsx-one-expression-per-line" = "off"
"react/jsx-props-no-multi-spaces" = "off"
"react/jsx-tag-spacing" = "off"
"react/jsx-wrap-multilines" = "off"
"symbol-description" = "error"
"unicode-bom" = ["error", "never"]
"unicorn/consistent-empty-array-spread" = "error"
"unicorn/empty-brace-spaces" = "off"
"unicorn/error-message" = "error"
"unicorn/escape-case" = ["error", "uppercase"]
"unicorn/new-for-builtins" = "error"
"unicorn/no-abusive-eslint-disable" = "error"
"unicorn/no-instanceof-builtins" = [
  "error",
  { useErrorIsError = false, strategy = "loose", include = [], exclude = [] },
]
"unicorn/no-nested-ternary" = "off"
"unicorn/no-new-array" = "error"
"unicorn/no-new-buffer" = "error"
"unicorn/number-literal-case" = "off"
"unicorn/prefer-array-some" = "error"
"unicorn/prefer-date-now" = "error"
"unicorn/prefer-dom-node-text-content" = "error"
"unicorn/prefer-includes" = "error"
"unicorn/prefer-node-protocol" = "error"
"unicorn/prefer-number-properties" = [
  "error",
  { checkInfinity = false, checkNaN = true },
]
"unicorn/prefer-regexp-test" = "error"
"unicorn/prefer-string-starts-ends-with" = "error"
"unicorn/prefer-type-error" = "error"
"unicorn/throw-new-error" = "error"
"use-isnan" = [
  "error",
  { enforceForIndexOf = true, enforceForSwitchCase = true },
]
"valid-typeof" = ["error", { requireStringLiterals = true }]
"vars-on-top" = "error"
"yoda" = ["error", "never", { exceptRange = false, onlyEquality = false }]

# eslint-plugin-regexp, run as a JavaScript plugin (loads without the eslint package)
"regexp/confusing-quantifier" = "warn"
"regexp/control-character-escape" = "error"
"regexp/match-any" = "error"
"regexp/negation" = "error"
"regexp/no-contradiction-with-assertion" = "error"
"regexp/no-dupe-characters-character-class" = "error"
"regexp/no-dupe-disjunctions" = "error"
"regexp/no-empty-alternative" = "warn"
"regexp/no-empty-capturing-group" = "error"
"regexp/no-empty-character-class" = "error"
"regexp/no-empty-group" = "error"
"regexp/no-empty-lookarounds-assertion" = "error"
"regexp/no-empty-string-literal" = "error"
"regexp/no-escape-backspace" = "error"
"regexp/no-extra-lookaround-assertions" = "error"
"regexp/no-invalid-regexp" = "error"
"regexp/no-invisible-character" = "error"
"regexp/no-lazy-ends" = "warn"
"regexp/no-legacy-features" = "error"
"regexp/no-misleading-capturing-group" = "error"
"regexp/no-misleading-unicode-character" = "error"
"regexp/no-missing-g-flag" = "error"
"regexp/no-non-standard-flag" = "error"
"regexp/no-obscure-range" = "error"
"regexp/no-optional-assertion" = "error"
"regexp/no-potentially-useless-backreference" = "warn"
"regexp/no-super-linear-backtracking" = "error"
"regexp/no-trivially-nested-assertion" = "error"
"regexp/no-trivially-nested-quantifier" = "error"
"regexp/no-unused-capturing-group" = "error"
"regexp/no-useless-assertions" = "error"
"regexp/no-useless-backreference" = "error"
"regexp/no-useless-character-class" = "error"
"regexp/no-useless-dollar-replacements" = "error"
"regexp/no-useless-escape" = "error"
"regexp/no-useless-flag" = "warn"
"regexp/no-useless-lazy" = "error"
"regexp/no-useless-non-capturing-group" = "error"
"regexp/no-useless-quantifier" = "error"
"regexp/no-useless-range" = "error"
"regexp/no-useless-set-operand" = "error"
"regexp/no-useless-string-literal" = "error"
"regexp/no-useless-two-nums-quantifier" = "error"
"regexp/no-zero-quantifier" = "error"
"regexp/optimal-lookaround-quantifier" = "warn"
"regexp/optimal-quantifier-concatenation" = "error"
"regexp/prefer-character-class" = "error"
"regexp/prefer-d" = "error"
"regexp/prefer-plus-quantifier" = "error"
"regexp/prefer-predefined-assertion" = "error"
"regexp/prefer-question-quantifier" = "error"
"regexp/prefer-range" = "error"
"regexp/prefer-set-operation" = "error"
"regexp/prefer-star-quantifier" = "error"
"regexp/prefer-unicode-codepoint-escapes" = "error"
"regexp/prefer-w" = "error"
"regexp/simplify-set-operations" = "error"
"regexp/sort-flags" = "error"
"regexp/strict" = "error"
"regexp/use-ignore-case" = "error"

[[lint.overrides]]
files = [
  "**/__tests__/**",
  "**/*.spec.*",
  "**/*.test.*",
  "**/*.bench.*",
  "**/*.benchmark.*",
]
rules = { "bun:test/consistent-test-it" = "off", "bun:test/no-focused-tests" = "error", "bun:test/no-identical-title" = "error", "bun:test/prefer-hooks-in-order" = "off", "bun:test/prefer-lowercase-title" = "off", "n/no-top-level-await" = "off", "vitest/no-import-node-test" = "error", "no-restricted-globals" = ["error", { message = "Use `globalThis` instead.", name = "global" }, { message = "Use `globalThis` instead.", name = "self" }, { message = "Import it: `import { Buffer } from \"node:buffer\"`.", name = "Buffer" }] } # Q4; antfu turns node/prefer-global/process off in tests

[[lint.overrides]]
files = ["packages/bun-ui/**", "examples/bun-ui/**"]
rules = { "react/error-boundaries" = "error", "react/exhaustive-deps" = "warn", "react/iframe-missing-sandbox" = "warn", "react/jsx-key" = "error", "react/jsx-no-comment-textnodes" = "warn", "react/jsx-no-script-url" = "warn", "react/no-access-state-in-setstate" = "error", "react/no-array-index-key" = "warn", "react/no-children-prop" = "warn", "react/no-clone-element" = "warn", "react/no-danger" = "warn", "react/no-danger-with-children" = "error", "react/no-did-mount-set-state" = "warn", "react/no-did-update-set-state" = "warn", "react/no-direct-mutation-state" = "error", "react/no-find-dom-node" = "error", "react/no-namespace" = "error", "react/no-render-return-value" = "error", "react/no-unsafe" = "warn", "react/no-unstable-nested-components" = "error", "react/no-unused-class-component-methods" = "warn", "react/no-will-update-set-state" = "warn", "react/only-export-components" = ["error", { allowConstantExport = false, allowExportNames = [] }], "react/purity" = "warn", "react/rules-of-hooks" = "error", "react/set-state-in-effect" = "warn", "react/set-state-in-render" = "error", "react/static-components" = "error", "react/unsupported-syntax" = "error", "react/use-memo" = "error", "react/void-dom-elements-no-children" = "error" }

# bun-client's React binding (PR-C6) and its tests: the hooks rules, nothing of the app rules above.
[[lint.overrides]]
files = [
  "packages/bun-client/lib/react.ts",
  "packages/bun-client/__tests__/react/**",
  "packages/bun-client/__tests__/react.type-test.ts",
]
rules = { "react/exhaustive-deps" = "warn", "react/jsx-key" = "error", "react/rules-of-hooks" = "error" }

# antfu's per-glob disables (antfu/disables/scripts, cli, dts, cjs, config-files), kept as they are today.
[[lint.overrides]]
files = ["**/scripts/**", "**/cli/**", "**/cli.*", "**/*.config.*"]
rules = { "n/no-top-level-await" = "off" }
[[lint.overrides]]
files = ["**/*.d.ts", "**/*.d.mts", "**/*.d.cts"]
rules = { "@typescript-eslint/no-unused-vars" = "off", "unicorn/no-abusive-eslint-disable" = "off" }
[[lint.overrides]]
files = ["**/*.js", "**/*.cjs"]
rules = { "@typescript-eslint/no-require-imports" = "off" }

# CLI entry points: printing is the product, and top-level await blocks no importer.
# benchmarks/ joined in PR F, with the two rules its ESLint config turned off.
[[lint.overrides]]
files = [
  "scripts/**",
  "playground/**",
  "examples/**",
  "templates/*/scripts/**",
  "benchmarks/**",
]
rules = { "no-console" = "off", "n/no-top-level-await" = "off" }

# Q12: in tests, the type-aware rules that flag test idiom (untyped fixtures, async callbacks with no await) are off.
[[lint.overrides]]
files = ["**/__tests__/**", "**/*.spec.*", "**/*.test.*"]
rules = { "@typescript-eslint/no-unsafe-argument" = "off", "@typescript-eslint/no-unsafe-assignment" = "off", "@typescript-eslint/no-unsafe-call" = "off", "@typescript-eslint/no-unsafe-member-access" = "off", "@typescript-eslint/no-unsafe-return" = "off", "@typescript-eslint/require-await" = "off", "@typescript-eslint/await-thenable" = "off" }

# Q5: Bun's default bug rules stay on, except bun:test/no-export in the shared test helpers.
[[lint.overrides]]
files = ["**/__tests__/helpers/**"]
rules = { "bun:test/no-export" = "off" }

[fmt]
singleAttributePerLine = true # the one option we set that is not Prettier's default
# Q3: Markdown is not formatted; Q2: no sortImports. Files a tool writes are not
# formatted either, so regenerating one never fails `bun fmt --check`: test
# timings (`--update-timings`), benchmark baselines (`--save-baseline`) and
# lerna.json (`lerna version`).
ignorePatterns = [
  "**/*.md",
  "docs/**",
  "benchmarks/results/**",
  "**/bun-timings*.json",
  "**/baselines/*.json",
  "lerna.json",
]