loopback-sandbox

A repository for reproducing LoopBack community issues.

Error Description

When calling the REST API operation PUT /Test/{id}, the beforeRemote remote hook is triggered after the datasource is accessed to verifiy if the object with this id exists in the datasource. But according to the definition of the beforeRmote hook, it should be executed before anything else.

To call the functions I use the explorer on 0.0.0.0:3000/explorer. I added a simple Test model, and added a beforeRemote hook, an afterRemote hook, and an overridden getDataSource to the test.js (with console logs).

Note: In this example I use the memory db. But the same applies for mysql or mongodb database. If you want to check an example with the mysql, then check the branch mysql-test.

Examples

1. Showing a correct case, using GET /Tests I try to get the list of Test objects, which should return an empty list, since nothing has been added.

   curl -X GET --header "Accept: application/json" "http://0.0.0.0:3000/api/Tests"

   Console Output:

    model.beforeRemote: find
    model.getDataSource
    model.getDataSource
    model.getDataSource
    model.afterRemote: find
   

   Explorer Response Body:

    []
   

   Explorer Response Code

    200
   

   In this case, first the beforeRemote hook triggers, then the data source is accessed, then the afterRemote triggers.

2. Showing the error case, using PUT /Tests{id} I try to update a Test object with id 1, which does not exist

   curl -X PUT --header "Content-Type: application/json" --header "Accept: application/json" -d "{\"id\": 1}" "http://0.0.0.0:3000/api/Tests/1"

   Console Output:

    model.getDataSource
    model.getDataSource
    model.getDataSource
    model.getDataSource
    model.getDataSource
   

   Explorer Response Body:

    {
      "error": {
        "name": "Error",
        "status": 404,
        "message": "could not find a model with id 1",
        "statusCode": 404,
        "code": "MODEL_NOT_FOUND",
        "stack": "Error: could not find a model with id 1\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback/lib/model.js:166:19\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1629:62\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1561:9\n    at Object.async.each (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/node_modules/async/lib/async.js:153:20)\n    at allCb (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1497:13)\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/connectors/memory.js:435:7\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/async-listener/glue.js:188:31\n    at doNTCallback0 (node.js:428:9)\n    at process._tickDomainCallback (node.js:398:13)\n    at process.<anonymous> (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/async-listener/index.js:19:15)"
      }
    }
   

   Explorer Response Code

    404
   

   In this case, the datasource is accessed to check if the object with this id exists, but no beforeRemote hook has been triggered, and because the check for id fails, no beforeRemote hook is triggered at all.

3. Showing error case, using PUT /Tests{id} to update, but first adding an object with the given id using POST /Tests

   1. curl -X POST --header "Content-Type: application/json" --header "Accept: application/json" -d "{\"id\": 1}" "http://0.0.0.0:3000/api/Tests"

      Console Output:

       model.beforeRemote: create
       model.getDataSource
       model.getDataSource
       model.getDataSource
       model.getDataSource
       model.afterRemote: create
      

      Explorer Response Body:

       {
         "id": 1
       }
      

      Explorer Response Code

       200
      

   2. curl -X PUT --header "Content-Type: application/json" --header "Accept: application/json" -d "{\"id\": 1}" "http://0.0.0.0:3000/api/Tests/1"

      Console Output:

       	model.getDataSource
       	model.getDataSource
       	model.getDataSource
       	model.getDataSource
       	model.getDataSource
       	model.beforeRemote: updateAttributes
       	model.getDataSource
       	model.getDataSource
       	model.afterRemote: updateAttributes
      

      Explorer Response Body:

       	{
       	  "id": 1
       	}
      

      Explorer Response Code

       	200
      

   This time, the call succeeds, since I have added the object before, but again the datasource is accessed before the beforeRemote hook triggers.

   I can also give a more verbose Console Debug where I print the names of the functions which are executed in the loopback-datasource-juggler dao.js:

   Verbose Console Output:

    	findById
    	findOne
    	find
    	getConnector
    	_getSetting
    	findById
    	model.getDataSource
    	findOne
    	model.getDataSource
    	find
    	model.getDataSource
    	getConnector
    	model.getDataSource
    	_getSetting
    	model.getDataSource
    	find
    	getConnector
    	_getSetting
    	model.beforeRemote: updateAttributes
    	updateAttributes
    	getConnector
    	_forDB
    	model.getDataSource
    	model.getDataSource
    	model.afterRemote: updateAttributes
   

4. I updated the code and added the access hook with observe('access') on the Test model. And I added the code to update the datasource based on the user (the remote context with the access token is injected in server/boot/context_injection.js). Moreover, the getDataSource now does not return the default data source anymore, but returns an undefined if the datasource was not updated previously based on the current user. But it still does not work, the access hook is not executed before the datasource is accessed. So there is no way to update the datasource in the case of the PUT /Tests{id} remote.

   1. curl -X PUT --header "Content-Type: application/json" --header "Accept: application/json" -d "{\"id\": 1}" "http://0.0.0.0:3000/api/Tests/1"

   Console Output:

    model.getDataSource: undefined
   

   Explorer Response Body:

    {
      "error": {
        "name": "TypeError",
        "status": 500,
        "message": "Cannot read property 'ready' of undefined",
        "stack": "TypeError: Cannot read property 'ready' of undefined\n    at stillConnecting (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:409:22)\n    at Function.findById (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:900:27)\n    at Function.ModelCtor.sharedCtor (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback/lib/model.js:160:19)\n    at SharedMethod.invoke (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/strong-remoting/lib/shared-method.js:248:25)\n    at HttpContext.invoke (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/strong-remoting/lib/http-context.js:382:12)\n    at restPrototypeMethodHandler (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/strong-remoting/lib/rest-adapter.js:427:9)\n    at Layer.handle [as handle_request] (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/express/lib/router/layer.js:95:5)\n    at next (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/express/lib/router/route.js:131:13)\n    at Route.dispatch (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/express/lib/router/route.js:112:3)\n    at Layer.handle [as handle_request] (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/express/lib/router/layer.js:95:5)"
      }
    }
   

   Explorer Response Code

    500
   

   2. curl -X GET --header "Accept: application/json" "http://0.0.0.0:3000/api/Tests"

   Console Output:

    model.beforeRemote: find
    inject
    attach default
    model.getDataSource: db
    model.getDataSource: db
    model.getDataSource: db
    model.access: undefined
    model.afterRemote: find
   

   Explorer Response Body:

    []
   

   Explorer Response Code

    200
   

   3. curl -X PUT --header "Content-Type: application/json" --header "Accept: application/json" -d "{\"id\": 1}" "http://0.0.0.0:3000/api/Tests/1"

   Console Output:

    model.getDataSource: db
    model.getDataSource: db
    model.getDataSource: db
    model.getDataSource: db
    model.getDataSource: db
    model.access: undefined
   

   Explorer Response Body:

    {
      "error": {
        "name": "Error",
        "status": 404,
        "message": "could not find a model with id 1",
        "statusCode": 404,
        "code": "MODEL_NOT_FOUND",
        "stack": "Error: could not find a model with id 1\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback/lib/model.js:166:19\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1629:62\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1561:9\n    at Object.async.each (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/node_modules/async/lib/async.js:153:20)\n    at allCb (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/dao.js:1497:13)\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/loopback-datasource-juggler/lib/connectors/memory.js:435:7\n    at /data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/async-listener/glue.js:188:31\n    at doNTCallback0 (node.js:428:9)\n    at process._tickDomainCallback (node.js:398:13)\n    at process.<anonymous> (/data/Projects/dobots/CloudAPI/examples/loopback-sandbox/node_modules/async-listener/index.js:19:15)"
      }
    }
   

   Explorer Response Code

    404
   

   Note: Because in step 4.2 I called the GET /Tests, the datasource was updated. So this time that I exeucte the `PUT /Tests/{id}, it uses the previously attached data source and accesses that datasource BEFORE the access hook is triggered. And aside from this problem, the access hook doesn't have the remote context injected anyway!