@eslint/plugin-kit 0.7.3

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/%40eslint/plugin-kit@0.7.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40eslint/plugin-kit@0.7.3

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:8e1345fcd4ba81747c06ca7ad69ef050efda497b634401928dc94246a188c6f1","constraints":{"executionContext":"node"},"contract":["assert TextSourceCodeBase resolves unist position-style nodes for getLoc and getRange","assert TextSourceCodeBase constructor accepts custom lineEndingPattern for CRLF line breaking and index mapping","assert TextSourceCodeBase traverse yields enter and exit VisitNodeStep instances and CallMethodStep instances","assert TextSourceCodeBase getText retrieves node text with beforeCount and afterCount bounds","assert ConfigCommentParser parseDirective returns undefined for comments not matching directive format","assert Directive represents enable, disable, disable-line, and disable-next-line directive types"],"goal":"verify pkg:npm/%40eslint/plugin-kit@0.7.3","kind":"HOW","packages":["pkg:npm/%40eslint/plugin-kit@0.7.3"],"schemaVersion":1},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40eslint/plugin-kit@0.7.3"],"schemaVersion":1,"subject":"pkg:npm/%40eslint/plugin-kit@0.7.3","verifierAdapter":"node-typescript@1"}

const {
  TextSourceCodeBase,
  VisitNodeStep,
  CallMethodStep,
  ConfigCommentParser,
  Directive,
} = require('@eslint/plugin-kit');

/**
 * Custom SourceCode class supporting AST traversal and Unist-style position nodes.
 */
class PluginSourceCode extends TextSourceCodeBase {
  #parents = new Map();

  getParent(node) {
    return this.#parents.get(node);
  }

  setParent(node, parent) {
    this.#parents.set(node, parent);
  }

  /**
   * Traverses AST yielding VisitNodeStep (enter and exit) and CallMethodStep.
   * @returns {Iterable<object>}
   */
  *traverse() {
    const self = this;
    function* walk(node, parent) {
      if (!node) return;
      self.#parents.set(node, parent);

      yield new VisitNodeStep({
        target: node,
        phase: 1,
        args: [node, parent],
      });

      yield new CallMethodStep({
        target: 'onNodeEnter',
        args: [node.type || 'Unknown'],
      });

      if (Array.isArray(node.children)) {
        for (const child of node.children) {
          yield* walk(child, node);
        }
      }

      yield new VisitNodeStep({
        target: node,
        phase: 2,
        args: [node, parent],
      });
    }

    yield* walk(this.ast, null);
  }

  /**
   * Extracts disable/enable directives from comment nodes.
   * @param {Array<{ value: string }>} commentNodes
   * @returns {Array<Directive>}
   */
  extractDirectives(commentNodes) {
    const parser = new ConfigCommentParser();
    const directives = [];

    for (const comment of commentNodes) {
      const parsed = parser.parseDirective(comment.value);
      if (!parsed) {
        continue;
      }

      if (parsed.label.startsWith('eslint-')) {
        const directiveType = parsed.label.slice('eslint-'.length);
        if (['disable', 'enable', 'disable-line', 'disable-next-line'].includes(directiveType)) {
          directives.push(
            new Directive({
              type: directiveType,
              node: comment,
              value: parsed.value,
              justification: parsed.justification,
            })
          );
        }
      }
    }

    return directives;
  }
}

module.exports = {
  PluginSourceCode,
  TextSourceCodeBase,
  VisitNodeStep,
  CallMethodStep,
  ConfigCommentParser,
  Directive,
};

{
  "name": "sample-eslint-plugin-kit",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-eslint-plugin-kit",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@eslint/plugin-kit": "0.7.3"
      }
    },
    "node_modules/@eslint/core": {
      "version": "1.2.1",
      "resolved": "https://registry.npmjs.org/@eslint/core/-/core-1.2.1.tgz",
      "integrity": "sha512-MwcE1P+AZ4C6DWlpin/OmOA54mmIZ/+xZuJiQd4SyB29oAJjN30UW9wkKNptW2ctp4cEsvhlLY/CsQ1uoHDloQ==",
      "license": "Apache-2.0",
      "dependencies": {
        "@types/json-schema": "^7.0.15"
      },
      "engines": {
        "node": "^20.19.0 || ^22.13.0 || >=24"
      }
    },
    "node_modules/@eslint/plugin-kit": {
      "version": "0.7.3",
      "resolved": "https://registry.npmjs.org/@eslint/plugin-kit/-/plugin-kit-0.7.3.tgz",
      "integrity": "sha512-IkO+/KEUvwbVpiURZg+P7zF74z5Jxe0UgJxVni+RtoHQ6IZieXaO02kmadomap/q+l6bc/jdPGGqTjhuZnuz1Q==",
      "license": "Apache-2.0",
      "dependencies": {
        "@eslint/core": "^1.2.1",
        "levn": "^0.4.1"
      },
      "engines": {
        "node": "^20.19.0 || ^22.13.0 || >=24"
      }
    },
    "node_modules/@types/json-schema": {
      "version": "7.0.15",
      "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.15.tgz",
      "integrity": "sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA==",
      "license": "MIT"
    },
    "node_modules/levn": {
      "version": "0.4.1",
      "resolved": "https://registry.npmjs.org/levn/-/levn-0.4.1.tgz",
      "integrity": "sha512-+bT2uH4E5LGE7h/n3evcS/sQlJXCpIp6ym8OWJ5eV6+67Dsql/LaaT7qJBAt2rzfoa/5QBGBhxDix1dMt2kQKQ==",
      "license": "MIT",
      "dependencies": {
        "prelude-ls": "^1.2.1",
        "type-check": "~0.4.0"
      },
      "engines": {
        "node": ">= 0.8.0"
      }
    },
    "node_modules/prelude-ls": {
      "version": "1.2.1",
      "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.2.1.tgz",
      "integrity": "sha512-vkcDPrRZo1QZLbn5RLGPpg/WmIQ65qoWWhcGKf/b5eplkkarX0m9z8ppCat4mlOqUsWpyNuYgO3VRyrYHSzX5g==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8.0"
      }
    },
    "node_modules/type-check": {
      "version": "0.4.0",
      "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
      "integrity": "sha512-XleUoc9uwGXqjWwXaUTZAmzMcFZ5858QA2vvx1Ur5xIcixXIP+8LnFDgRplU30us6teqdlskFfu+ae4K79Ooew==",
      "license": "MIT",
      "dependencies": {
        "prelude-ls": "^1.2.1"
      },
      "engines": {
        "node": ">= 0.8.0"
      }
    }
  }
}

{
  "name": "sample-eslint-plugin-kit",
  "version": "1.0.0",
  "description": "Clean-room sample verifying @eslint/plugin-kit custom source code and traversal",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "@eslint/plugin-kit": "0.7.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/%40eslint/plugin-kit@0.7.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40eslint/plugin-kit@0.7.3"
  ]
}

import assert from 'node:assert';
import {
  PluginSourceCode,
  TextSourceCodeBase,
  ConfigCommentParser,
} from '../index.js';

// 1. assert TextSourceCodeBase resolves unist position-style nodes for getLoc and getRange
const headingNode = {
  type: 'heading',
  position: {
    start: { line: 1, column: 1, offset: 0 },
    end: { line: 1, column: 14, offset: 13 },
  },
};
const sourceText = '# Hello World\nSecond line\n';
const rootNode = {
  type: 'root',
  position: {
    start: { line: 1, column: 1, offset: 0 },
    end: { line: 2, column: 12, offset: 25 },
  },
  children: [headingNode],
};

const pluginCode = new PluginSourceCode({ ast: rootNode, text: sourceText });
const loc = pluginCode.getLoc(headingNode);
assert.deepStrictEqual(loc, headingNode.position);
const range = pluginCode.getRange(headingNode);
assert.deepStrictEqual(range, [0, 13]);

// 2. assert TextSourceCodeBase constructor accepts custom lineEndingPattern for CRLF line breaking and index mapping
const crlfText = 'first line\r\nsecond line\r\nthird line';
const crlfAst = {
  type: 'root',
  loc: {
    start: { line: 1, column: 0 },
    end: { line: 3, column: 10 },
  },
};
const crlfCode = new TextSourceCodeBase({
  text: crlfText,
  ast: crlfAst,
  lineEndingPattern: /\r\n/u,
});
assert.deepStrictEqual(crlfCode.lines, ['first line', 'second line', 'third line']);

const locSecond = crlfCode.getLocFromIndex(12);
assert.strictEqual(locSecond.line, 2);
assert.strictEqual(locSecond.column, 0);

const idxSecond = crlfCode.getIndexFromLoc({ line: 2, column: 0 });
assert.strictEqual(idxSecond, 12);

// 3. assert TextSourceCodeBase traverse yields enter and exit VisitNodeStep instances and CallMethodStep instances
const steps = Array.from(pluginCode.traverse());
assert.ok(steps.length >= 4);

const enterSteps = steps.filter(s => s.type === 'visit' && s.phase === 1);
assert.strictEqual(enterSteps.length, 2);
assert.strictEqual(enterSteps[0].target, rootNode);
assert.strictEqual(enterSteps[0].kind, 1);
assert.strictEqual(enterSteps[1].target, headingNode);

const callSteps = steps.filter(s => s.type === 'call' && s.target === 'onNodeEnter');
assert.strictEqual(callSteps.length, 2);
assert.strictEqual(callSteps[0].kind, 2);
assert.deepStrictEqual(callSteps.map(s => s.args), [['root'], ['heading']]);

const exitSteps = steps.filter(s => s.type === 'visit' && s.phase === 2);
assert.strictEqual(exitSteps.length, 2);
assert.strictEqual(exitSteps[0].target, headingNode);
assert.strictEqual(exitSteps[1].target, rootNode);

// 4. assert TextSourceCodeBase getText retrieves node text with beforeCount and afterCount bounds
const innerNode = {
  type: 'text',
  position: {
    start: { line: 1, column: 3, offset: 2 },
    end: { line: 1, column: 14, offset: 13 },
  },
};
assert.strictEqual(pluginCode.getText(innerNode), 'Hello World');
assert.strictEqual(pluginCode.getText(innerNode, 2), '# Hello World');
assert.strictEqual(pluginCode.getText(innerNode, 2, 1), '# Hello World\n');

// 5. assert ConfigCommentParser parseDirective returns undefined for comments not matching directive format
const parser = new ConfigCommentParser();
assert.strictEqual(parser.parseDirective('TODO: refactor this function'), undefined);
assert.strictEqual(parser.parseDirective('1234 invalid directive'), undefined);
assert.strictEqual(parser.parseDirective(''), undefined);

// 6. assert Directive represents enable, disable, disable-line, and disable-next-line directive types
const commentList = [
  { value: 'eslint-disable-next-line no-console -- temporary log' },
  { value: 'eslint-disable no-alert' },
  { value: 'eslint-enable no-alert -- re-enable' },
  { value: 'eslint-disable-line no-debugger' },
  { value: 'regular comment without directive' },
];
const directives = pluginCode.extractDirectives(commentList);
assert.strictEqual(directives.length, 4);

assert.strictEqual(directives[0].type, 'disable-next-line');
assert.strictEqual(directives[0].value, 'no-console');
assert.strictEqual(directives[0].justification, 'temporary log');

assert.strictEqual(directives[1].type, 'disable');
assert.strictEqual(directives[1].value, 'no-alert');
assert.strictEqual(directives[1].justification, '');

assert.strictEqual(directives[2].type, 'enable');
assert.strictEqual(directives[2].value, 'no-alert');
assert.strictEqual(directives[2].justification, 're-enable');

assert.strictEqual(directives[3].type, 'disable-line');
assert.strictEqual(directives[3].value, 'no-debugger');

console.log('All contract assertions passed.');