@block65/oxlint

oxlint with five added type-aware rules and eight changed upstream rules. The five added rules are implemented in @block65/oxlint-tsgolint, and package.json declares the oldest build of it they work with as an optional peer dependency on oxlint-tsgolint. Linux x64 and arm64 only, the platforms Block65 runs. The package version names the upstream release it is built on, as described under Versioning.

# pnpm-workspace.yaml
overrides:
  oxlint: npm:@block65/oxlint@[version]
  oxlint-tsgolint: npm:@block65/oxlint-tsgolint@[version]

Added rules

All five are typescript/ rules in the restriction category. They run in tsgolint, so they need --type-aware. Four report a place where a finite type is erased, and one a value invented where a finite type would have named the choice.

• define-messages-keys: defineMessages whose keys are not a finite union of string or number literals. A call with no type argument passes when it resolves to an overload with a const type parameter, as react-intl 12's does, since that already keeps the literal keys.
• no-open-string-fallback: an inline string literal after ?? or ??=, or as a destructuring default outside a parameter, where the operand is an open string or a literal union the value is outside. A member of the union chooses a default and a named value is a typed default, so both pass. The empty string is left to the block65 plugin's no-sentinel-fallback.
• no-widening-alias: a const whose annotation is wider than its initializer, such as string over a literal union or Record<string, T> over an object with known keys.
• no-widening-object-keys: Object.keys or Object.entries on a value with a finite key type. Options keys and entries name the helpers to use instead; the defaults are typedKeys and typedEntries.
• no-widening-return-type: a return annotation wider than what the body returns, such as boolean over return true. Option contracts (default true) allows a named object type as the annotation.

Changed rules

typescript/no-inferrable-types reports a primitive annotation it considers redundant and suggests deleting it. On a const holding a literal the annotation is not redundant: const a: number = 5 is typed number, while const a = 5 is typed 5. Deleting it narrows the type, and on an exported declaration that narrows what every other file sees.

In this build the rule stops reporting that case for number, string, boolean and bigint. It still reports const a: 5 = 5, where the annotation matches what inference already gives, and let, var, parameters and properties, which widen on their own.

Five unicorn/ rules report what they did upstream, but --fix applies fewer of their rewrites. Where a rewrite can change behaviour or types, it is offered as a suggestion instead, which --fix-suggestions applies, or not offered at all:

• prefer-single-call merges push() and unshift() calls only on a variable known to be an array: annotated T[] or Array<T>, or initialised with an array and never reassigned. Any other receiver may have a push() that takes one argument, such as a stream's.
• no-typeof-undefined does not rewrite inside a generic function or class. typeof value === "undefined" narrows a value of an unconstrained type parameter to undefined, and value === undefined does not.
• no-useless-undefined does not rewrite these in TypeScript files: return undefined and () => undefined, which change an inferred return type from undefined to void; a parameter's = undefined default, which makes the parameter required; and trailing undefined arguments, which can leave a call short of a required parameter.
• prefer-dom-node-append rewrites appendChild() only where its result is discarded, since append() returns undefined.
• prefer-query-selector rewrites only a literal argument that means the same as a selector: an id, class or tag name of ASCII letters, digits, _ and - that does not start with a digit, or a name without quotes. An id held in a variable would need CSS.escape(), and "address.line1" as a selector matches a class.

unicorn/catch-error-name keeps the key of a shorthand property it renames: { cause } becomes { cause: err }, not { err }.

Four unicorn/ rules report less than they do upstream:

• new-for-builtins reports Object() but not Object(value), a conversion TypeScript types as any, while new Object(value) is typed Object.
• prefer-math-trunc does not report an integer literal shifted left by zero, such as 1 << 0 at the start of a bit-flag sequence.
• explicit-length-check does not report .length or .size before || with a string fallback, such as props.size || "base", where the property is a string.
• no-useless-undefined does not report return undefined in a TypeScript function that also returns a value. Under noImplicitReturns every path must then return explicitly.

unicorn/number-literal-case takes upstream unicorn's hexadecimalValue option, "uppercase" (the default) or "lowercase". oxfmt lower-cases hex digits, so ["error", { "hexadecimalValue": "lowercase" }] agrees with it.

Versioning

The patch is upstream's patch times 100 plus a build number. Upstream 1.83.0 gives 1.83.0, then 1.83.1; an upstream 1.83.1 would give 1.83.100. The major and minor are upstream's, so oxlint ranges keep resolving.