ADD: can now walk json that contains arrays

I feel like this is kind of a hack to handle a change with Auth0 where
the actual user id is inside of an array of identities. While I do think
it would be good to build an actual plugin for Auth0 to better handle
their use case I do feel that it is important that we can handle Auth0
with this plugin for now.

plugin.rb

@@ -50,8 +50,12 @@ class OAuth2BasicAuthenticator < ::Auth::OAuth2Authenticator
   def walk_path(fragment, segments)
     first_seg = segments[0]
     return if first_seg.blank? || fragment.blank?
-    return nil unless fragment.is_a?(Hash)
-    deref = fragment[first_seg] || fragment[first_seg.to_sym]
+    return nil unless fragment.is_a?(Hash) || fragment.is_a?(Array)
+    if fragment.is_a?(Hash)
+      deref = fragment[first_seg] || fragment[first_seg.to_sym]
+    else
+      deref = fragment[0] # Take just the first array for now, maybe later we can teach it to walk the array if we need to
+    end
 
     return (deref.blank? || segments.size == 1) ? deref : walk_path(deref, segments[1..-1])
   end

spec/plugin_spec.rb

@@ -1,4 +1,5 @@
 require 'rails_helper'
+require 'json'
 
 # This is ugly... but it works!
 # Need to load plugin.rb to avoid:
@@ -40,4 +41,32 @@ describe OAuth2BasicAuthenticator do
       expect(result.user).to eq(user)
     end
   end
+
+  it 'can walk json' do
+    authenticator = OAuth2BasicAuthenticator.new('oauth2_basic')
+    json_string = '{"user":{"id":1234,"email":{"address":"test@example.com"}}}'
+    SiteSetting.oauth2_json_email_path = 'user.email.address'
+    result = authenticator.json_walk({}, JSON.parse(json_string), :email)
+
+    expect(result).to eq "test@example.com"
+  end
+
+  it 'can walk json that contains an array' do
+    authenticator = OAuth2BasicAuthenticator.new('oauth2_basic')
+    json_string = '{"email":"test@example.com","identities":[{"user_id":"123456789","provider":"auth0","isSocial":false}]}'
+    SiteSetting.oauth2_json_user_id_path = 'identities.[].user_id'
+    result = authenticator.json_walk({}, JSON.parse(json_string), :user_id)
+
+    expect(result).to eq "123456789"
+  end
+
+  it 'can walk json and handle an empty array' do
+    authenticator = OAuth2BasicAuthenticator.new('oauth2_basic')
+    json_string = '{"email":"test@example.com","identities":[]}'
+    SiteSetting.oauth2_json_user_id_path = 'identities.[].user_id'
+    result = authenticator.json_walk({}, JSON.parse(json_string), :user_id)
+
+    expect(result).to eq nil
+  end
+
 end