source: node_modules/swagger-client/es/specmap/lib/all-of.js

import { isFreelyNamed, generateAbsoluteRefPatches } from '../helpers.js';
export default {
  key: 'allOf',
  plugin: (val, key, fullPath, specmap, patch) => {
    // Ignore replace patches created by $ref because the changes will
    // occur in the original "add" patch and we don't want this plugin
    // to redundantly processes those "relace" patches.
    if (patch.meta && patch.meta.$$ref) {
      return undefined;
    }
    const parent = fullPath.slice(0, -1);
    if (isFreelyNamed(parent)) {
      return undefined;
    }
    if (!Array.isArray(val)) {
      const err = new TypeError('allOf must be an array');
      err.fullPath = fullPath; // This is an array
      return err;
    }
    let alreadyAddError = false;

    // Find the original definition from the `patch.value` object
    // Remove the `allOf` property so it doesn't get added to the result of the `allOf` plugin
    let originalDefinitionObj = patch.value;
    parent.forEach(part => {
      if (!originalDefinitionObj) return; // bail out if we've lost sight of our target
      originalDefinitionObj = originalDefinitionObj[part];
    });
    originalDefinitionObj = {
      ...originalDefinitionObj
    };

    // when we've lost sight, interrupt prematurely
    if (Object.keys(originalDefinitionObj).length === 0) {
      return undefined;
    }
    delete originalDefinitionObj.allOf;
    const patches = [];

    // remove existing content
    patches.push(specmap.replace(parent, {}));
    val.forEach((toMerge, i) => {
      if (!specmap.isObject(toMerge)) {
        if (alreadyAddError) {
          return null;
        }
        alreadyAddError = true;
        const err = new TypeError('Elements in allOf must be objects');
        err.fullPath = fullPath; // This is an array
        return patches.push(err);
      }

      // Deeply merge the member's contents onto the parent location
      patches.push(specmap.mergeDeep(parent, toMerge));

      // Generate patches that migrate $ref values based on ContextTree information

      // remove ["allOf"], which will not be present when these patches are applied
      const collapsedFullPath = fullPath.slice(0, -1);
      const absoluteRefPatches = generateAbsoluteRefPatches(toMerge, collapsedFullPath, {
        getBaseUrlForNodePath: nodePath => specmap.getContext([...fullPath, i, ...nodePath]).baseDoc,
        specmap
      });
      patches.push(...absoluteRefPatches);
      return undefined;
    });

    // If there was an example in the original definition,
    // keep it instead of merging with examples from other schema
    if (originalDefinitionObj.example) {
      // Delete other schema examples
      patches.push(specmap.remove([].concat(parent, 'example')));
    }
    // Merge back the values from the original definition
    patches.push(specmap.mergeDeep(parent, originalDefinitionObj));

    // If there was not an original $$ref value, make sure to remove
    // any $$ref value that may exist from the result of `allOf` merges
    if (!originalDefinitionObj.$$ref) {
      patches.push(specmap.remove([].concat(parent, '$$ref')));
    }
    return patches;
  }
};