Android Test Project - Reading assets file to test plain java object

Question

My project setup

Library Project A Contains a fooJSONParser like this :

public class fooJsonParser {
  ...
  // Constructor using the input-stream
  public DPNodeJsonParser(InputStream inputJsonStream) {
    // Constructor
  }

  /**
   * Method that has to be executed once the class is instantiated to parse
   */
  public parsedObject parseObj() {
    // Parses and prints the info
  }

App Project B, which uses the Library Project A

Problem

Now I have created a Test Project tester to test the App Project B and add a test case to test the fooJsonParser class. Everytime there is new json data, I update the parse method and want to test it using the tester project and see if the parser is parsing correctly instead of installing, running the app and navigating to the screen where that new json data would be used. For accomplishing this, I am having a json file in the assets folder of the tester. But I'm not sure how I can read the json file. I think this has something to do with MockContext but wasn't sure how to use it as the documentation says all methods are non-functional.

Could somebody suggest a solution/provide a sample to read the asset file from a plain java object test case?

I'm fairly new to the android testing environment. Let me know If anything is unclear. I can add more information.

I have a similar problem. Was your assets in the `App Project B`'s asset folder or in the `tester`'s asset folder? — Code-Apprentice, Nov 25 '13 at 03:41

yorkw · Answer 1 · 2012-03-01T03:43:51.970

Suppose you have assets folder that contain json_sample.txt, If I recall, you can get it from a POJO by this:

String testFile = "json_sample.txt";
InputStream in = this.getClass().getClassLoader().getResourceAsStream(testFile);

I remember I did this in one of my project long times ago, not use if you need add assets/ as prefix of testFile, try it out.

UPDATE:
I just realized that the assets folder is no longer automatically added to project build path, probably since r14. I am pretty sure it was before (same as res folder). The file must under the build path, in order to make the code work, your need manually add assets folder into project build path, right click your project -- Build Path -- Configure Build Path, add assets folder as a Source folders on build path. or move your file into res folder alternatively.

Android file system is quite restricted and I doubt if there is another way to read asserts file from a POJO.

score 2 · Accepted Answer · answered Mar 03 '12 at 19:46

2

I got this solved by the following :

Created the setup as explained here
Extended the InstrumentationTestCase instead of TestCase. The InstrumentationTestCase has the method getInstrument() through which I got access to the Instrumentation's(The test app project) Context.

answered Mar 03 '12 at 19:46

500865

6,920
7
44
87

2

Yes, this is the normal way we do it, check out my anwser [here](http://stackoverflow.com/questions/6547783/storing-test-files-in-the-test-project) 6 month ago. But strictly speaking, this is not what you asked, Yor asked for how to do it from a POJO, I probably mis-understand your question. – yorkw Mar 03 '12 at 20:24

score 0 · Answer 3 · edited May 23 '17 at 12:15

0

Since Android Gradle Plugin version 1.1 you haven't to use Instrumentation to load file resource.

I wrote here how to do it with POJO unit test case.

edited May 23 '17 at 12:15

Community

1
1

answered Apr 08 '15 at 09:17

klimat

24,711
7
63
70

Android Test Project - Reading assets file to test plain java object

3 Answers3

Linked