@redocly/openapi-core/src/rules/oas3/boolean-parameter-prefixes.ts

See https://github.com/Redocly/openapi-cli

import { Oas3Rule } from '../../visitors';

export type BooleanParameterPrefixesOptions = {
  prefixes?: string[];
};

export const BooleanParameterPrefixes: Oas3Rule = (options: BooleanParameterPrefixesOptions) => {
  const prefixes = options.prefixes || ['is', 'has'];
  const regexp = new RegExp(`^(${prefixes.join('|')})[A-Z-_]`);
  const wrappedPrefixes = prefixes.map((p) => `\`${p}\``);
  const prefixesString =
    wrappedPrefixes.length === 1
      ? wrappedPrefixes[0]
      : wrappedPrefixes.slice(0, -1).join(', ') + ' or ' + wrappedPrefixes[prefixes.length - 1];

  return {
    Parameter: {
      Schema(schema, { report, parentLocations }, parents) {
        if (schema.type === 'boolean' && !regexp.test(parents.Parameter.name)) {
          report({
            message: `Boolean parameter \`${parents.Parameter.name}\` should have ${prefixesString} prefix.`,
            location: parentLocations.Parameter.child(['name']),
          });
        }
      },
    },
  };
};