refactor(populate): move getModelsMapForPopulate() into separate fu…

…nction

Fix #7962

lib/helpers/populate/getModelsMapForPopulate.js

@@ -0,0 +1,398 @@
+'use strict';
+
+const MongooseError = require('../../error/index');
+const get = require('../get');
+const isPathExcluded = require('../projection/isPathExcluded');
+const getSchemaTypes = require('./getSchemaTypes');
+const getVirtual = require('./getVirtual');
+const normalizeRefPath = require('./normalizeRefPath');
+const util = require('util');
+const utils = require('../../utils');
+
+const modelSymbol = require('../symbols').modelSymbol;
+const populateModelSymbol = require('../symbols').populateModelSymbol;
+const schemaMixedSymbol = require('../../schema/symbols').schemaMixedSymbol;
+
+module.exports = function getModelsMapForPopulate(model, docs, options) {
+  let i;
+  let doc;
+  const len = docs.length;
+  const available = {};
+  const map = [];
+  const modelNameFromQuery = options.model && options.model.modelName || options.model;
+  let schema;
+  let refPath;
+  let Model;
+  let currentOptions;
+  let modelNames;
+  let modelName;
+  let modelForFindSchema;
+
+  const originalModel = options.model;
+  let isVirtual = false;
+  const modelSchema = model.schema;
+
+  for (i = 0; i < len; i++) {
+    doc = docs[i];
+
+    schema = getSchemaTypes(modelSchema, doc, options.path);
+    const isUnderneathDocArray = schema && schema.$isUnderneathDocArray;
+    if (isUnderneathDocArray && get(options, 'options.sort') != null) {
+      return new MongooseError('Cannot populate with `sort` on path ' + options.path +
+        ' because it is a subproperty of a document array');
+    }
+
+    modelNames = null;
+    let isRefPath = false;
+    if (Array.isArray(schema)) {
+      for (let j = 0; j < schema.length; ++j) {
+        let _modelNames;
+        try {
+          const res = _getModelNames(doc, schema[j]);
+          _modelNames = res.modelNames;
+          isRefPath = res.isRefPath;
+        } catch (error) {
+          return error;
+        }
+        if (!_modelNames) {
+          continue;
+        }
+        modelNames = modelNames || [];
+        for (let x = 0; x < _modelNames.length; ++x) {
+          if (modelNames.indexOf(_modelNames[x]) === -1) {
+            modelNames.push(_modelNames[x]);
+          }
+        }
+      }
+    } else {
+      try {
+        const res = _getModelNames(doc, schema);
+        modelNames = res.modelNames;
+        isRefPath = res.isRefPath;
+      } catch (error) {
+        return error;
+      }
+
+      if (!modelNames) {
+        continue;
+      }
+    }
+
+    const virtual = getVirtual(model.schema, options.path);
+    let localField;
+    let count = false;
+    if (virtual && virtual.options) {
+      const virtualPrefix = virtual.$nestedSchemaPath ?
+        virtual.$nestedSchemaPath + '.' : '';
+      if (typeof virtual.options.localField === 'function') {
+        localField = virtualPrefix + virtual.options.localField.call(doc, doc);
+      } else {
+        localField = virtualPrefix + virtual.options.localField;
+      }
+      count = virtual.options.count;
+    } else {
+      localField = options.path;
+    }
+    let foreignField = virtual && virtual.options ?
+      virtual.options.foreignField :
+      '_id';
+
+    // `justOne = null` means we don't know from the schema whether the end
+    // result should be an array or a single doc. This can result from
+    // populating a POJO using `Model.populate()`
+    let justOne = null;
+    if ('justOne' in options) {
+      justOne = options.justOne;
+    } else if (virtual && virtual.options && virtual.options.refPath) {
+      const normalizedRefPath =
+        normalizeRefPath(virtual.options.refPath, doc, options.path);
+      justOne = !!virtual.options.justOne;
+      isVirtual = true;
+      const refValue = utils.getValue(normalizedRefPath, doc);
+      modelNames = Array.isArray(refValue) ? refValue : [refValue];
+    } else if (virtual && virtual.options && virtual.options.ref) {
+      let normalizedRef;
+      if (typeof virtual.options.ref === 'function') {
+        normalizedRef = virtual.options.ref.call(doc, doc);
+      } else {
+        normalizedRef = virtual.options.ref;
+      }
+      justOne = !!virtual.options.justOne;
+      isVirtual = true;
+      if (!modelNames) {
+        modelNames = [].concat(normalizedRef);
+      }
+    } else if (schema && !schema[schemaMixedSymbol]) {
+      // Skip Mixed types because we explicitly don't do casting on those.
+      justOne = !schema.$isMongooseArray;
+    }
+
+    if (!modelNames) {
+      continue;
+    }
+
+    if (virtual && (!localField || !foreignField)) {
+      return new MongooseError('If you are populating a virtual, you must set the ' +
+        'localField and foreignField options');
+    }
+
+    options.isVirtual = isVirtual;
+    options.virtual = virtual;
+    if (typeof localField === 'function') {
+      localField = localField.call(doc, doc);
+    }
+    if (typeof foreignField === 'function') {
+      foreignField = foreignField.call(doc);
+    }
+
+    const localFieldPathType = modelSchema._getPathType(localField);
+    const localFieldPath = localFieldPathType === 'real' ? modelSchema.paths[localField] : localFieldPathType.schema;
+    const localFieldGetters = localFieldPath && localFieldPath.getters ? localFieldPath.getters : [];
+    let ret;
+
+    const _populateOptions = get(options, 'options', {});
+
+    const getters = 'getters' in _populateOptions ?
+      _populateOptions.getters :
+      options.isVirtual && get(virtual, 'options.getters', false);
+    if (localFieldGetters.length > 0 && getters) {
+      const hydratedDoc = (doc.$__ != null) ? doc : model.hydrate(doc);
+      const localFieldValue = utils.getValue(localField, doc);
+      if (Array.isArray(localFieldValue)) {
+        const localFieldHydratedValue = utils.getValue(localField.split('.').slice(0, -1), hydratedDoc);
+        ret = localFieldValue.map((localFieldArrVal, localFieldArrIndex) =>
+          localFieldPath.applyGetters(localFieldArrVal, localFieldHydratedValue[localFieldArrIndex]));
+      } else {
+        ret = localFieldPath.applyGetters(localFieldValue, hydratedDoc);
+      }
+    } else {
+      ret = convertTo_id(utils.getValue(localField, doc));
+    }
+
+    const id = String(utils.getValue(foreignField, doc));
+    options._docs[id] = Array.isArray(ret) ? ret.slice() : ret;
+
+    let match = get(options, 'match', null) ||
+      get(currentOptions, 'match', null) ||
+      get(options, 'virtual.options.options.match', null);
+
+    const hasMatchFunction = typeof match === 'function';
+    if (hasMatchFunction) {
+      match = match.call(doc, doc);
+    }
+
+    let k = modelNames.length;
+    while (k--) {
+      modelName = modelNames[k];
+      if (modelName == null) {
+        continue;
+      }
+
+      // `PopulateOptions#connection`: if the model is passed as a string, the
+      // connection matters because different connections have different models.
+      const connection = options.connection != null ? options.connection : model.db;
+
+      try {
+        Model = originalModel && originalModel[modelSymbol] ?
+          originalModel :
+          modelName[modelSymbol] ? modelName : connection.model(modelName);
+      } catch (error) {
+        return error;
+      }
+
+      let ids = ret;
+      const flat = Array.isArray(ret) ? utils.array.flatten(ret) : [];
+      if (isRefPath && Array.isArray(ret) && flat.length === modelNames.length) {
+        ids = flat.filter((val, i) => modelNames[i] === modelName);
+      }
+
+      if (!available[modelName]) {
+        currentOptions = {
+          model: Model
+        };
+
+        if (isVirtual && virtual.options && virtual.options.options) {
+          currentOptions.options = utils.clone(virtual.options.options);
+        }
+        utils.merge(currentOptions, options);
+
+        // Used internally for checking what model was used to populate this
+        // path.
+        options[populateModelSymbol] = Model;
+
+        available[modelName] = {
+          model: Model,
+          options: currentOptions,
+          match: hasMatchFunction ? [match] : match,
+          docs: [doc],
+          ids: [ids],
+          allIds: [ret],
+          localField: new Set([localField]),
+          foreignField: new Set([foreignField]),
+          justOne: justOne,
+          isVirtual: isVirtual,
+          virtual: virtual,
+          count: count,
+          [populateModelSymbol]: Model
+        };
+        map.push(available[modelName]);
+      } else {
+        available[modelName].localField.add(localField);
+        available[modelName].foreignField.add(foreignField);
+        available[modelName].docs.push(doc);
+        available[modelName].ids.push(ids);
+        available[modelName].allIds.push(ret);
+        if (hasMatchFunction) {
+          available[modelName].match.push(match);
+        }
+      }
+    }
+  }
+
+  function _getModelNames(doc, schema) {
+    let modelNames;
+    let discriminatorKey;
+    let isRefPath = false;
+
+    if (schema && schema.caster) {
+      schema = schema.caster;
+    }
+    if (schema && schema.$isSchemaMap) {
+      schema = schema.$__schemaType;
+    }
+
+    if (!schema && model.discriminators) {
+      discriminatorKey = model.schema.discriminatorMapping.key;
+    }
+
+    refPath = schema && schema.options && schema.options.refPath;
+
+    const normalizedRefPath = normalizeRefPath(refPath, doc, options.path);
+
+    if (modelNameFromQuery) {
+      modelNames = [modelNameFromQuery]; // query options
+    } else if (normalizedRefPath) {
+      if (options._queryProjection != null && isPathExcluded(options._queryProjection, normalizedRefPath)) {
+        throw new MongooseError('refPath `' + normalizedRefPath +
+          '` must not be excluded in projection, got ' +
+          util.inspect(options._queryProjection));
+      }
+      modelNames = utils.getValue(normalizedRefPath, doc);
+      if (Array.isArray(modelNames)) {
+        modelNames = utils.array.flatten(modelNames);
+      }
+
+      isRefPath = true;
+    } else {
+      let modelForCurrentDoc = model;
+      let schemaForCurrentDoc;
+
+      if (!schema && discriminatorKey) {
+        modelForFindSchema = utils.getValue(discriminatorKey, doc);
+
+        if (modelForFindSchema) {
+          try {
+            modelForCurrentDoc = model.db.model(modelForFindSchema);
+          } catch (error) {
+            return error;
+          }
+
+          schemaForCurrentDoc = modelForCurrentDoc.schema._getSchema(options.path);
+
+          if (schemaForCurrentDoc && schemaForCurrentDoc.caster) {
+            schemaForCurrentDoc = schemaForCurrentDoc.caster;
+          }
+        }
+      } else {
+        schemaForCurrentDoc = schema;
+      }
+      const virtual = getVirtual(modelForCurrentDoc.schema, options.path);
+
+      let ref;
+      if ((ref = get(schemaForCurrentDoc, 'options.ref')) != null) {
+        ref = handleRefFunction(ref, doc);
+        modelNames = [ref];
+      } else if ((ref = get(virtual, 'options.ref')) != null) {
+        ref = handleRefFunction(ref, doc);
+
+        // When referencing nested arrays, the ref should be an Array
+        // of modelNames.
+        if (Array.isArray(ref)) {
+          modelNames = ref;
+        } else {
+          modelNames = [ref];
+        }
+
+        isVirtual = true;
+      } else {
+        // We may have a discriminator, in which case we don't want to
+        // populate using the base model by default
+        modelNames = discriminatorKey ? null : [model.modelName];
+      }
+    }
+
+    if (!modelNames) {
+      return { modelNames: modelNames, isRefPath: isRefPath };
+    }
+
+    if (!Array.isArray(modelNames)) {
+      modelNames = [modelNames];
+    }
+
+    return { modelNames: modelNames, isRefPath: isRefPath };
+  }
+
+  return map;
+};
+
+/*!
+ * ignore
+ */
+
+function handleRefFunction(ref, doc) {
+  if (typeof ref === 'function' && !ref[modelSymbol]) {
+    return ref.call(doc, doc);
+  }
+  return ref;
+}
+
+/*!
+ * Retrieve the _id of `val` if a Document or Array of Documents.
+ *
+ * @param {Array|Document|Any} val
+ * @return {Array|Document|Any}
+ */
+
+function convertTo_id(val) {
+  if (val != null && val.$__ != null) return val._id;
+
+  if (Array.isArray(val)) {
+    for (let i = 0; i < val.length; ++i) {
+      if (val[i] != null && val[i].$__ != null) {
+        val[i] = val[i]._id;
+      }
+    }
+    if (val.isMongooseArray && val.$schema()) {
+      return val.$schema().cast(val, val.$parent());
+    }
+
+    return [].concat(val);
+  }
+
+  // `populate('map')` may be an object if populating on a doc that hasn't
+  // been hydrated yet
+  if (val != null && val.constructor.name === 'Object') {
+    const ret = [];
+    for (const key of Object.keys(val)) {
+      ret.push(val[key]);
+    }
+    return ret;
+  }
+  // If doc has already been hydrated, e.g. `doc.populate('map').execPopulate()`
+  // then `val` will already be a map
+  if (val instanceof Map) {
+    return Array.from(val.values());
+  }
+
+  return val;
+}