Commit

node_modules/mongoose/lib/helpers/model/discriminator.js

@@ -0,0 +1,265 @@
+'use strict';
+
+const Mixed = require('../../schema/mixed');
+const applyBuiltinPlugins = require('../schema/applyBuiltinPlugins');
+const clone = require('../clone');
+const defineKey = require('../document/compile').defineKey;
+const get = require('../get');
+const utils = require('../../utils');
+const mergeDiscriminatorSchema = require('../../helpers/discriminator/mergeDiscriminatorSchema');
+
+const CUSTOMIZABLE_DISCRIMINATOR_OPTIONS = {
+  toJSON: true,
+  toObject: true,
+  _id: true,
+  id: true,
+  virtuals: true,
+  methods: true,
+  statics: true
+};
+
+/**
+ * Validate fields declared on the child schema when either schema is configured for encryption.  Specifically, this function ensures that:
+ *
+ * - any encrypted fields are declared on exactly one of the schemas (not both)
+ * - encrypted fields cannot be declared on either the parent or child schema, where the other schema declares the same field without encryption.
+ *
+ * @param {Schema} parentSchema
+ * @param {Schema} childSchema
+ */
+function validateDiscriminatorSchemasForEncryption(parentSchema, childSchema) {
+  if (parentSchema.encryptionType() == null && childSchema.encryptionType() == null) return;
+
+  const allSharedNestedPaths = setIntersection(
+    allNestedPaths(parentSchema),
+    allNestedPaths(childSchema)
+  );
+
+  for (const path of allSharedNestedPaths) {
+    if (parentSchema._hasEncryptedField(path) && childSchema._hasEncryptedField(path)) {
+      throw new Error(`encrypted fields cannot be declared on both the base schema and the child schema in a discriminator. path=${path}`);
+    }
+
+    if (parentSchema._hasEncryptedField(path) || childSchema._hasEncryptedField(path)) {
+      throw new Error(`encrypted fields cannot have the same path as a non-encrypted field for discriminators. path=${path}`);
+    }
+  }
+
+  function allNestedPaths(schema) {
+    return [...Object.keys(schema.paths), ...Object.keys(schema.singleNestedPaths)];
+  }
+
+  /**
+   * @param {Iterable<string>} i1
+   * @param {Iterable<string>} i2
+   */
+  function* setIntersection(i1, i2) {
+    const s1 = new Set(i1);
+    for (const item of i2) {
+      if (s1.has(item)) {
+        yield item;
+      }
+    }
+  }
+}
+
+/*!
+ * ignore
+ */
+
+module.exports = function discriminator(model, name, schema, tiedValue, applyPlugins, mergeHooks, overwriteExisting) {
+  if (!(schema && schema.instanceOfSchema)) {
+    throw new Error('You must pass a valid discriminator Schema');
+  }
+
+  mergeHooks = mergeHooks == null ? true : mergeHooks;
+
+  if (model.schema.discriminatorMapping &&
+      !model.schema.discriminatorMapping.isRoot) {
+    throw new Error('Discriminator "' + name +
+        '" can only be a discriminator of the root model');
+  }
+
+  if (applyPlugins) {
+    const applyPluginsToDiscriminators = get(model.base,
+      'options.applyPluginsToDiscriminators', false) || !mergeHooks;
+    // Even if `applyPluginsToDiscriminators` isn't set, we should still apply
+    // global plugins to schemas embedded in the discriminator schema (gh-7370)
+    model.base._applyPlugins(schema, {
+      skipTopLevel: !applyPluginsToDiscriminators
+    });
+  } else if (!mergeHooks) {
+    applyBuiltinPlugins(schema);
+  }
+
+  const key = model.schema.options.discriminatorKey;
+
+  const existingPath = model.schema.path(key);
+  if (existingPath != null) {
+    if (!utils.hasUserDefinedProperty(existingPath.options, 'select')) {
+      existingPath.options.select = true;
+    }
+    existingPath.options.$skipDiscriminatorCheck = true;
+  } else {
+    const baseSchemaAddition = {};
+    baseSchemaAddition[key] = {
+      default: void 0,
+      select: true,
+      $skipDiscriminatorCheck: true
+    };
+    baseSchemaAddition[key][model.schema.options.typeKey] = String;
+    model.schema.add(baseSchemaAddition);
+    defineKey({
+      prop: key,
+      prototype: model.prototype,
+      options: model.schema.options
+    });
+  }
+
+  if (schema.path(key) && schema.path(key).options.$skipDiscriminatorCheck !== true) {
+    throw new Error('Discriminator "' + name +
+        '" cannot have field with name "' + key + '"');
+  }
+
+  let value = name;
+  if ((typeof tiedValue === 'string' && tiedValue.length) || tiedValue != null) {
+    value = tiedValue;
+  }
+
+  validateDiscriminatorSchemasForEncryption(model.schema, schema);
+
+  function merge(schema, baseSchema) {
+    // Retain original schema before merging base schema
+    schema._baseSchema = baseSchema;
+    if (baseSchema.paths._id &&
+        baseSchema.paths._id.options &&
+        !baseSchema.paths._id.options.auto) {
+      schema.remove('_id');
+    }
+
+    // Find conflicting paths: if something is a path in the base schema
+    // and a nested path in the child schema, overwrite the base schema path.
+    // See gh-6076
+    const baseSchemaPaths = Object.keys(baseSchema.paths);
+    const conflictingPaths = [];
+
+    for (const path of baseSchemaPaths) {
+      if (schema.nested[path]) {
+        conflictingPaths.push(path);
+        continue;
+      }
+
+      if (path.indexOf('.') === -1) {
+        continue;
+      }
+      const sp = path.split('.').slice(0, -1);
+      let cur = '';
+      for (const piece of sp) {
+        cur += (cur.length ? '.' : '') + piece;
+        if (schema.paths[cur] instanceof Mixed ||
+            schema.singleNestedPaths[cur] instanceof Mixed) {
+          conflictingPaths.push(path);
+        }
+      }
+    }
+
+    // Shallow clone `obj` so we can add additional properties without modifying original
+    // schema. `Schema.prototype.clone()` copies `obj` by reference, no cloning.
+    schema.obj = { ...schema.obj };
+    mergeDiscriminatorSchema(schema, baseSchema);
+    schema._gatherChildSchemas();
+
+    // Clean up conflicting paths _after_ merging re: gh-6076
+    for (const conflictingPath of conflictingPaths) {
+      delete schema.paths[conflictingPath];
+    }
+
+    // Rebuild schema models because schemas may have been merged re: #7884
+    schema.childSchemas.forEach(obj => {
+      obj.model.prototype.$__setSchema(obj.schema);
+    });
+
+    const obj = {};
+    obj[key] = {
+      default: value,
+      select: true,
+      set: function(newName) {
+        if (newName === value || (Array.isArray(value) && utils.deepEqual(newName, value))) {
+          return value;
+        }
+        throw new Error('Can\'t set discriminator key "' + key + '"');
+      },
+      $skipDiscriminatorCheck: true
+    };
+    obj[key][schema.options.typeKey] = existingPath ? existingPath.options[schema.options.typeKey] : String;
+    schema.add(obj);
+
+    schema.discriminatorMapping = { key: key, value: value, isRoot: false };
+
+    if (baseSchema.options.collection) {
+      schema.options.collection = baseSchema.options.collection;
+    }
+    const toJSON = schema.options.toJSON;
+    const toObject = schema.options.toObject;
+    const _id = schema.options._id;
+    const id = schema.options.id;
+
+    const keys = Object.keys(schema.options);
+    schema.options.discriminatorKey = baseSchema.options.discriminatorKey;
+    const userProvidedOptions = schema._userProvidedOptions;
+    for (const _key of keys) {
+      if (!CUSTOMIZABLE_DISCRIMINATOR_OPTIONS[_key]) {
+        // Use `schema.options` in `deepEqual()` because of `discriminatorKey`
+        // set above. We don't allow customizing discriminator key, always
+        // overwrite. See gh-9238
+        if (_key in userProvidedOptions && !utils.deepEqual(schema.options[_key], baseSchema.options[_key])) {
+          throw new Error('Can\'t customize discriminator option ' + _key +
+            ' (can only modify ' +
+            Object.keys(CUSTOMIZABLE_DISCRIMINATOR_OPTIONS).join(', ') +
+            ')');
+        }
+      }
+    }
+    schema.options = clone(baseSchema.options);
+
+    for (const _key of Object.keys(userProvidedOptions)) {
+      schema.options[_key] = userProvidedOptions[_key];
+    }
+    if (toJSON) schema.options.toJSON = toJSON;
+    if (toObject) schema.options.toObject = toObject;
+    if (typeof _id !== 'undefined') {
+      schema.options._id = _id;
+    }
+    schema.options.id = id;
+    if (mergeHooks) {
+      schema.s.hooks = model.schema.s.hooks.merge(schema.s.hooks);
+    }
+    if (applyPlugins) {
+      schema.plugins = Array.prototype.slice.call(baseSchema.plugins);
+    }
+    schema.callQueue = baseSchema.callQueue.concat(schema.callQueue);
+    delete schema._requiredpaths; // reset just in case Schema#requiredPaths() was called on either schema
+  }
+
+  // merges base schema into new discriminator schema and sets new type field.
+  merge(schema, model.schema);
+
+  if (!model.discriminators) {
+    model.discriminators = {};
+  }
+
+  if (!model.schema.discriminatorMapping) {
+    model.schema.discriminatorMapping = { key: key, value: null, isRoot: true };
+  }
+  if (!model.schema.discriminators) {
+    model.schema.discriminators = {};
+  }
+
+  model.schema.discriminators[name] = schema;
+
+  if (model.discriminators[name] && !schema.options.overwriteModels && !overwriteExisting) {
+    throw new Error('Discriminator with name "' + name + '" already exists');
+  }
+
+  return schema;
+};