Any auto grading site that supports all-testcases-in-one-file (and/or in github)? I use repl.it,  and one problem i note, is that each new test case has to be added by many gui-web clicks.
it is both slow and annoying, and makes it harder to :
1) send to other teacher to review the testcase
2) store the assignment in github ( for backup/ development/review)
3) see all tests cases at once
4) transfer info between sites ( if a better site is found, i want to transfer all the assignments data inc. testcases easily to the better site).

Saw in another SE-CS-educators thread, STEPIK  site and in some other thread VPL for Moodle was suggested. 
How many have used VPL-Moodle for K12 ?   and STEPIK ?    (  grades 10-12) 
Are there any other autograder sites, that support one-file-that-contains-all-test-cases  ?
At the TU Delft we've developed WebLab, which is used in various CS related courses. It has support for programming assignments, for which students code their solutions in a web-editor, and run their code against their own tests, and the spec-tests.


Grades are automatically calculated based on the number of succeeding specification tests.


As a Course Manager, you specify the spec-tests by writing JUnit tests in a single file (in case of Java).
Students can run the spec-tests, and the UI will only reveal the test score to students, while managers have access to the complete output of the program.

Optionally, the automatically computed grade can be combined with manual grading components (e.g. a checklist).


It provides an interface to walk over all submissions. 
Each Grader can be assigned their share of the submissions to be graded



Other types of assignments supported include: Essay questions (manual grading), Multiple Choice questions (automatic grading), File Submission questions (manual grading) and Peer Review questions (manual grading). For programming assignments it has built-in support for Java, Scala, Python and C, but this can be extended with any language for which you can provide a Docker image that handles input/outputs results in WebLab format.

You can sign up and enrol for this demo-course to get an idea of its interface as a student.
If you're interested, we can set up a demo course for you by submitting a course request (sign in first).