fix(changeEmail) : add condition when email already used by an other account

src/users/users.service.ts

@@ -136,19 +136,24 @@ export class UsersService {
 
   public async changeUserEmail(newEmail: string, oldEmail: string) {
     const user = await this.findOne(oldEmail);
+    const alreadyUsed = await this.findOne(newEmail);
     if (user) {
-      const config = this.mailerService.config;
-      const ejsPath = this.mailerService.getTemplateLocation(config.templates.changeEmail.ejs);
-      const jsonConfig = this.mailerService.loadJsonConfig(config.templates.changeEmail.json);
-      const token = crypto.randomBytes(64).toString('hex');
-      const html = await ejs.renderFile(ejsPath, {
-        config,
-        token: token,
-      });
-      this.mailerService.send(user.email, jsonConfig.subject, html);
-      user.changeEmailToken = token;
-      user.newEmail = newEmail;
-      user.save();
+      if (!alreadyUsed) {
+        const config = this.mailerService.config;
+        const ejsPath = this.mailerService.getTemplateLocation(config.templates.changeEmail.ejs);
+        const jsonConfig = this.mailerService.loadJsonConfig(config.templates.changeEmail.json);
+        const token = crypto.randomBytes(64).toString('hex');
+        const html = await ejs.renderFile(ejsPath, {
+          config,
+          token: token,
+        });
+        this.mailerService.send(user.email, jsonConfig.subject, html);
+        user.changeEmailToken = token;
+        user.newEmail = newEmail;
+        user.save();
+        return user;
+      }
+      throw new HttpException('Email already used', HttpStatus.NOT_ACCEPTABLE);
     }
     throw new HttpException('Email sent if account exist', HttpStatus.OK);
   }