(core) Adding new column in users table "ref" with unique identifier.

Summary:
There is a new column in users table called ref (user reference).
It holds user's unique reference number that can be used for features
that require some kind of ownership logic (like comments).

Test Plan: Updated tests

Reviewers: georgegevoian, paulfitz

Reviewed By: georgegevoian, paulfitz

Differential Revision: https://phab.getgrist.com/D3641

app/gen-server/lib/HomeDBManager.ts

@@ -419,6 +419,15 @@ export class HomeDBManager extends EventEmitter {
     throw new Error(`Cannot testGetId(${name})`);
   }
 
+  /**
+   * For tests only. Get user's unique reference by name.
+   */
+  public async testGetRef(name: string): Promise<string> {
+    const user = await User.findOne({where: {name}});
+    if (user) { return user.ref; }
+    throw new Error(`Cannot testGetRef(${name})`);
+  }
+
   /**
    * Clear all user preferences associated with the given email addresses.
    * For use in tests.
@@ -2537,6 +2546,7 @@ export class HomeDBManager extends EventEmitter {
     const login = new Login();
     login.displayEmail = login.email = ANONYMOUS_USER_EMAIL;
     user.logins = [login];
+    user.ref = '';
     return user;
   }
 
@@ -3917,6 +3927,9 @@ export class HomeDBManager extends EventEmitter {
           cond = cond.orWhere(`gu3.user_id = ${users}`);
           // Support the special "everyone" user.
           const everyoneId = this._specialUserIds[EVERYONE_EMAIL];
+          if (everyoneId === undefined) {
+            throw new Error("Special user id for EVERYONE_EMAIL not found");
+          }
           cond = cond.orWhere(`gu0.user_id = ${everyoneId}`);
           cond = cond.orWhere(`gu1.user_id = ${everyoneId}`);
           cond = cond.orWhere(`gu2.user_id = ${everyoneId}`);
@@ -3925,6 +3938,9 @@ export class HomeDBManager extends EventEmitter {
             // Support also the special anonymous user.  Currently, by convention, sharing a
             // resource with anonymous should make it listable.
             const anonId = this._specialUserIds[ANONYMOUS_USER_EMAIL];
+            if (anonId === undefined) {
+              throw new Error("Special user id for ANONYMOUS_USER_EMAIL not found");
+            }
             cond = cond.orWhere(`gu0.user_id = ${anonId}`);
             cond = cond.orWhere(`gu1.user_id = ${anonId}`);
             cond = cond.orWhere(`gu2.user_id = ${anonId}`);