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/Controllers/DatabaseController.js

@@ -1299,6 +1299,7 @@ class DatabaseController {
   //   acl     restrict this operation with an ACL for the provided array
   //           of user objectIds and roles. acl: null means no user.
   //           when this field is not present, don't do anything regarding ACLs.
+  //  caseInsensitive make string comparisons case insensitive
   // TODO: make userIds not needed here. The db adapter shouldn't know
   // anything about users, ideally. Then, improve the format of the ACL
   // arg to work like the others.
@@ -1317,6 +1318,7 @@ class DatabaseController {
       pipeline,
       readPreference,
       hint,
+      caseInsensitive = false,
       explain,
     }: any = {},
     auth: any = {},
@@ -1368,6 +1370,7 @@ class DatabaseController {
               keys,
               readPreference,
               hint,
+              caseInsensitive,
               explain,
             };
             Object.keys(sort).forEach(fieldName => {
@@ -1723,6 +1726,24 @@ class DatabaseController {
         throw error;
       });
 
+    const usernameCaseInsensitiveIndex = userClassPromise
+      .then(() =>
+        this.adapter.ensureIndex(
+          '_User',
+          requiredUserFields,
+          ['username'],
+          'case_insensitive_username',
+          true
+        )
+      )
+      .catch(error => {
+        logger.warn(
+          'Unable to create case insensitive username index: ',
+          error
+        );
+        throw error;
+      });
+
     const emailUniqueness = userClassPromise
       .then(() =>
         this.adapter.ensureUniqueness('_User', requiredUserFields, ['email'])
@@ -1735,6 +1756,21 @@ class DatabaseController {
         throw error;
       });
 
+    const emailCaseInsensitiveIndex = userClassPromise
+      .then(() =>
+        this.adapter.ensureIndex(
+          '_User',
+          requiredUserFields,
+          ['email'],
+          'case_insensitive_email',
+          true
+        )
+      )
+      .catch(error => {
+        logger.warn('Unable to create case insensitive email index: ', error);
+        throw error;
+      });
+
     const roleUniqueness = roleClassPromise
       .then(() =>
         this.adapter.ensureUniqueness('_Role', requiredRoleFields, ['name'])
@@ -1752,7 +1788,9 @@ class DatabaseController {
     });
     return Promise.all([
       usernameUniqueness,
+      usernameCaseInsensitiveIndex,
       emailUniqueness,
+      emailCaseInsensitiveIndex,
       roleUniqueness,
       adapterInit,
       indexPromise,