node_modules/eslint-plugin-jsdoc/src/rules/requireFileOverview.js

import iterateJsdoc from '../iterateJsdoc.js';

const defaultTags = {
  file: {
    initialCommentsOnly: true,
    mustExist: true,
    preventDuplicates: true,
  },
};

/**
 * @param {import('../iterateJsdoc.js').StateObject} state
 * @returns {void}
 */
const setDefaults = (state) => {
  // First iteration
  if (!state.globalTags) {
    state.globalTags = true;
    state.hasDuplicates = {};
    state.hasTag = {};
    state.hasNonCommentBeforeTag = {};
  }
};

export default iterateJsdoc(({
  context,
  jsdocNode,
  state,
  utils,
}) => {
  const {
    tags = defaultTags,
  } = context.options[0] || {};

  setDefaults(state);

  for (const tagName of Object.keys(tags)) {
    const targetTagName = /** @type {string} */ (utils.getPreferredTagName({
      tagName,
    }));

    const hasTag = Boolean(targetTagName && utils.hasTag(targetTagName));

    state.hasTag[tagName] = hasTag || state.hasTag[tagName];

    const hasDuplicate = state.hasDuplicates[tagName];

    if (hasDuplicate === false) {
      // Was marked before, so if a tag now, is a dupe
      state.hasDuplicates[tagName] = hasTag;
    } else if (!hasDuplicate && hasTag) {
      // No dupes set before, but has first tag, so change state
      //   from `undefined` to `false` so can detect next time
      state.hasDuplicates[tagName] = false;
      state.hasNonCommentBeforeTag[tagName] = state.hasNonComment &&
        state.hasNonComment < jsdocNode.range[0];
    }
  }
}, {
  exit ({
    context,
    state,
    utils,
  }) {
    setDefaults(state);
    const {
      tags = defaultTags,
    } = context.options[0] || {};

    for (const [
      tagName,
      {
        initialCommentsOnly = false,
        mustExist = false,
        preventDuplicates = false,
      },
    ] of Object.entries(tags)) {
      const obj = utils.getPreferredTagNameObject({
        tagName,
      });
      if (obj && typeof obj === 'object' && 'blocked' in obj) {
        utils.reportSettings(
          `\`settings.jsdoc.tagNamePreference\` cannot block @${obj.tagName} ` +
          'for the `require-file-overview` rule',
        );
      } else {
        const targetTagName = (
          obj && typeof obj === 'object' && obj.replacement
        ) || obj;
        if (mustExist && !state.hasTag[tagName]) {
          utils.reportSettings(`Missing @${targetTagName}`);
        }

        if (preventDuplicates && state.hasDuplicates[tagName]) {
          utils.reportSettings(
            `Duplicate @${targetTagName}`,
          );
        }

        if (initialCommentsOnly &&
            state.hasNonCommentBeforeTag[tagName]
        ) {
          utils.reportSettings(
            `@${targetTagName} should be at the beginning of the file`,
          );
        }
      }
    }
  },
  iterateAllJsdocs: true,
  meta: {
    docs: {
      description: 'Checks that all files have one `@file`, `@fileoverview`, or `@overview` tag at the beginning of the file.',
      url: 'https://github.com/gajus/eslint-plugin-jsdoc/blob/main/docs/rules/require-file-overview.md#repos-sticky-header',
    },
    schema: [
      {
        additionalProperties: false,
        properties: {
          tags: {
            description: `The keys of this object are tag names, and the values are configuration
objects indicating what will be checked for these whole-file tags.

Each configuration object has 3 potential boolean keys (which default
to \`false\` when this option is supplied).

1. \`mustExist\` - enforces that all files have a \`@file\`, \`@fileoverview\`, or \`@overview\` tag.
2. \`preventDuplicates\` - enforces that duplicate file overview tags within a given file will be reported
3. \`initialCommentsOnly\` - reports file overview tags which are not, as per
  [the docs](https://jsdoc.app/tags-file.html), "at the beginning of
  the file"–where beginning of the file is interpreted in this rule
  as being when the overview tag is not preceded by anything other than
  a comment.

When no \`tags\` is present, the default is:

\`\`\`json
{
  "file": {
    "initialCommentsOnly": true,
    "mustExist": true,
    "preventDuplicates": true,
  }
}
\`\`\`

You can add additional tag names and/or override \`file\` if you supply this
option, e.g., in place of or in addition to \`file\`, giving other potential
file global tags like \`@license\`, \`@copyright\`, \`@author\`, \`@module\` or
\`@exports\`, optionally restricting them to a single use or preventing them
from being preceded by anything besides comments.

For example:

\`\`\`js
{
  "license": {
    "mustExist": true,
    "preventDuplicates": true,
  }
}
\`\`\`

This would require one and only one \`@license\` in the file, though because
\`initialCommentsOnly\` is absent and defaults to \`false\`, the \`@license\`
can be anywhere.

In the case of \`@license\`, you can use this rule along with the
\`check-values\` rule (with its \`allowedLicenses\` or \`licensePattern\` options),
to enforce a license whitelist be present on every JS file.

Note that if you choose to use \`preventDuplicates\` with \`license\`, you still
have a way to allow multiple licenses for the whole page by using the SPDX
"AND" expression, e.g., \`@license (MIT AND GPL-3.0)\`.

Note that the tag names are the main JSDoc tag name, so you should use \`file\`
in this configuration object regardless of whether you have configured
\`fileoverview\` instead of \`file\` on \`tagNamePreference\` (i.e., \`fileoverview\`
will be checked, but you must use \`file\` on the configuration object).`,
            patternProperties: {
              '.*': {
                additionalProperties: false,
                properties: {
                  initialCommentsOnly: {
                    type: 'boolean',
                  },
                  mustExist: {
                    type: 'boolean',
                  },
                  preventDuplicates: {
                    type: 'boolean',
                  },
                },
                type: 'object',
              },
            },
            type: 'object',
          },
        },
        type: 'object',
      },
    ],
    type: 'suggestion',
  },
  nonComment ({
    node,
    state,
  }) {
    if (!state.hasNonComment) {
      state.hasNonComment = /** @type {[number, number]} */ (node.range)?.[0];
    }
  },
});