Case insensitive signup (#5634)

* Always delete data after each, even for mongo.

* Add failing simple case test

* run all tests

* 1. when validating username be case insensitive

2. add _auth_data_anonymous to specialQueryKeys...whatever that is!

* More case sensitivity

1. also make email validation case insensitive
2. update comments to reflect what this change does

* wordsmithery and grammar

* first pass at a preformant case insensitive query.  mongo only so far.

* change name of parameter from insensitive to
caseInsensitive

* Postgres support

* properly handle auth data null

* wip

* use 'caseInsensitive' instead of 'insensitive' in all places.

* update commenet to reclect current plan

* skip the mystery test for now

* create case insensitive indecies for
mongo to support case insensitive
checks for email and username

* remove unneeded specialKey

* pull collation out to a function.

* not sure what i planned
to do with this test.
removing.

* remove typo

* remove another unused flag

* maintain order

* maintain order of params

* boil the ocean on param sequence
i like having explain last cause it seems
like something you would
change/remove after getting what you want
from the explain?

* add test to verify creation
and use of caseInsensitive index

* add no op func to prostgress

* get collation object from mongocollection
make flow lint happy by declaring things Object.

* fix typo

* add changelog

* kick travis

* properly reference static method

* add a test to confirm that anonymous users with
unique username that do collide when compared
insensitively can still be created.

* minot doc nits

* add a few tests to make sure our spy is working as expected
wordsmith the changelog

Co-authored-by: Diamond Lewis <findlewis@gmail.com>

src/Adapters/Storage/Mongo/MongoCollection.js

@@ -15,7 +15,17 @@ export default class MongoCollection {
   // idea. Or even if this behavior is a good idea.
   find(
     query,
-    { skip, limit, sort, keys, maxTimeMS, readPreference, hint, explain } = {}
+    {
+      skip,
+      limit,
+      sort,
+      keys,
+      maxTimeMS,
+      readPreference,
+      hint,
+      caseInsensitive,
+      explain,
+    } = {}
   ) {
     // Support for Full Text Search - $text
     if (keys && keys.$score) {
@@ -30,6 +40,7 @@ export default class MongoCollection {
       maxTimeMS,
       readPreference,
       hint,
+      caseInsensitive,
       explain,
     }).catch(error => {
       // Check for "no geoindex" error
@@ -60,6 +71,7 @@ export default class MongoCollection {
               maxTimeMS,
               readPreference,
               hint,
+              caseInsensitive,
               explain,
             })
           )
@@ -67,9 +79,26 @@ export default class MongoCollection {
     });
   }
 
+  /**
+   * Collation to support case insensitive queries
+   */
+  static caseInsensitiveCollation() {
+    return { locale: 'en_US', strength: 2 };
+  }
+
   _rawFind(
     query,
-    { skip, limit, sort, keys, maxTimeMS, readPreference, hint, explain } = {}
+    {
+      skip,
+      limit,
+      sort,
+      keys,
+      maxTimeMS,
+      readPreference,
+      hint,
+      caseInsensitive,
+      explain,
+    } = {}
   ) {
     let findOperation = this._mongoCollection.find(query, {
       skip,
@@ -83,6 +112,12 @@ export default class MongoCollection {
       findOperation = findOperation.project(keys);
     }
 
+    if (caseInsensitive) {
+      findOperation = findOperation.collation(
+        MongoCollection.caseInsensitiveCollation()
+      );
+    }
+
     if (maxTimeMS) {
       findOperation = findOperation.maxTimeMS(maxTimeMS);
     }

src/Adapters/Storage/Mongo/MongoStorageAdapter.js

@@ -620,7 +620,16 @@ export class MongoStorageAdapter implements StorageAdapter {
     className: string,
     schema: SchemaType,
     query: QueryType,
-    { skip, limit, sort, keys, readPreference, hint, explain }: QueryOptions
+    {
+      skip,
+      limit,
+      sort,
+      keys,
+      readPreference,
+      hint,
+      caseInsensitive,
+      explain,
+    }: QueryOptions
   ): Promise<any> {
     schema = convertParseSchemaToMongoSchema(schema);
     const mongoWhere = transformWhere(className, query, schema);
@@ -653,6 +662,7 @@ export class MongoStorageAdapter implements StorageAdapter {
           maxTimeMS: this._maxTimeMS,
           readPreference,
           hint,
+          caseInsensitive,
           explain,
         })
       )
@@ -667,6 +677,47 @@ export class MongoStorageAdapter implements StorageAdapter {
       .catch(err => this.handleError(err));
   }
 
+  ensureIndex(
+    className: string,
+    schema: SchemaType,
+    fieldNames: string[],
+    indexName: ?string,
+    caseInsensitive: boolean = false
+  ): Promise<any> {
+    schema = convertParseSchemaToMongoSchema(schema);
+    const indexCreationRequest = {};
+    const mongoFieldNames = fieldNames.map(fieldName =>
+      transformKey(className, fieldName, schema)
+    );
+    mongoFieldNames.forEach(fieldName => {
+      indexCreationRequest[fieldName] = 1;
+    });
+
+    const defaultOptions: Object = { background: true, sparse: true };
+    const indexNameOptions: Object = indexName ? { name: indexName } : {};
+    const caseInsensitiveOptions: Object = caseInsensitive
+      ? { collation: MongoCollection.caseInsensitiveCollation() }
+      : {};
+    const indexOptions: Object = {
+      ...defaultOptions,
+      ...caseInsensitiveOptions,
+      ...indexNameOptions,
+    };
+
+    return this._adaptiveCollection(className)
+      .then(
+        collection =>
+          new Promise((resolve, reject) =>
+            collection._mongoCollection.createIndex(
+              indexCreationRequest,
+              indexOptions,
+              error => (error ? reject(error) : resolve())
+            )
+          )
+      )
+      .catch(err => this.handleError(err));
+  }
+
   // Create a unique index. Unique indexes on nullable fields are not allowed. Since we don't
   // currently know which fields are nullable and which aren't, we ignore that criteria.
   // As such, we shouldn't expose this function to users of parse until we have an out-of-band