@systemfsoftware/stryker-ignorer-interface

The ignorer interface: the descriptor and the AST vocabulary an ignorer reasons about, as types only — the package ships no runtime code.

An ignorer is the smallest thing a StrykerJS-style mutation tool can load: a name and a synchronous decision over the node the host hands it, together with that node's ancestors. This package carries the shapes of that contract and nothing that runs. It has no Effect dependency, runtime or development: dependencies is empty, no value is exported, and the kitchen-sink family aggregate preset is replaced by @systemfsoftware/oxlint-ignorer-config, which bans Effect imports outright.

| Export | What it is | | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Ignorer | The descriptor: { name, shouldIgnore(node, ancestors): string \| undefined } — the node and its ancestors as typed positions, nearest first | | vocabulary | the AST vocabulary, re-exported from @oxc-project/types with optional spans and bundled into this package's own declarations, so a consumer installs nothing else — Node, Expression, Statement, Program, Span, and every concrete node interface | | Walker | the traversal shape a host implements: enter/leave receive each node and its ancestor stack — see the instrumenter's walker for the reference implementation over oxc-walker |

Everything the package publishes is a type. A guard and a reason string are the ignorer's own code: the host never interprets a schema, it calls shouldIgnore(node, ancestors) and uses what comes back.

Install

pnpm add -D @systemfsoftware/stryker-ignorer-interface

Write an ignorer

The authoring and testing kit — @systemfsoftware/stryker-ignorer-kit — is the from-scratch path: typed visitors via defineIgnorer, snippet cases via testIgnorer. The plain descriptor below is the wire contract the kit compiles to; reach for it directly only when the kit cannot express your rule.

import type { Ignorer, Node } from '@systemfsoftware/stryker-ignorer-interface'

const isGenerated = (node: Node): boolean => 'name' in node && node.name === '__generated'

const myIgnorer: Ignorer = {
  name: 'generated-code',
  shouldIgnore: (node, ancestors) =>
    isGenerated(node) || ancestors.some(isGenerated) ? 'the enclosing member is generated' : undefined,
}

export const strykerIgnorers = [myIgnorer]

An entry is just { name, shouldIgnore }: the host carries each one as that plain descriptor and validates at load that name is a string and shouldIgnore is callable — an entry that fails fails the load by name.

A module exporting strykerIgnorers loads in any engine carrying the plain-ignorer loader, and the host runs every ignorer the module contributes. List the module in ignorers with import.meta.resolve.

License

Apache 2.0