Fix #2294

Ideally we would not have this inconsistent edge case that we filter
through the user type. Much better would be a graphql query like:

```graphql
{
  User(filter: { primary_email: { email: "something@example.org" } }) {
    id
    name
    slug
  }
}
```

backend/src/middleware/permissionsMiddleware.js

@@ -100,7 +100,7 @@ const noEmailFilter = rule({
 const publicRegistration = rule()(() => !!CONFIG.PUBLIC_REGISTRATION)
 
 // Permissions
-const permissions = shield(
+export default shield(
   {
     Query: {
       '*': deny,
@@ -176,5 +176,3 @@ const permissions = shield(
     fallbackRule: allow,
   },
 )
-
-export default permissions

backend/src/schema/resolvers/users.js

@@ -49,10 +49,22 @@ export default {
     User: async (object, args, context, resolveInfo) => {
       const { email } = args
       if (email) {
-        const e = await instance.first('EmailAddress', { email })
-        let user = e.get('belongsTo')
-        user = await user.toJson()
-        return [user.node]
+        let session
+        try {
+          session = context.driver.session()
+          const readTxResult = await session.readTransaction(txc => {
+            const result = txc.run(
+              `
+            MATCH (user:User)-[:PRIMARY_EMAIL]->(e:EmailAddress {email: $args.email})
+            RETURN user`,
+              { args },
+            )
+            return result
+          })
+          return readTxResult.records.map(r => r.get('user').properties)
+        } finally {
+          session.close()
+        }
       }
       return neo4jgraphql(object, args, context, resolveInfo)
     },

backend/src/schema/resolvers/users.spec.js

@@ -70,6 +70,21 @@ describe('User', () => {
           data: { User: [{ name: 'Johnny' }] },
         })
       })
+
+      it('non-existing email address, issue #2294', async () => {
+        // see: https://github.com/Human-Connection/Human-Connection/issues/2294
+        await expect(
+          query({
+            query: userQuery,
+            variables: {
+              email: 'this-email-does-not-exist@example.org',
+            },
+          }),
+        ).resolves.toMatchObject({
+          data: { User: [] },
+          errors: undefined,
+        })
+      })
     })
   })
 })