Filtering Input Parameters to Childchain/Watcher API depending on HTTP Method

[kalouo]

Addresses #1411

Overview

This PR implements filtering for input parameters depending on the HTTP method used.

• For a POST: query_params will be ignored and body_params will be used.
• For a GET: body_params will be ignored and query_params will be used.

Changes

Creates plug in method_param_filter.ex files which are added to endpoint.ex in in both omg_childchain_rpc and omg_watcher_rpc to implement above logic.

Testing

• Tests written for method_param_filter.ex (two files: one for childchain and one for watcher)
• Tests added to selected endpoints on Watcher Info (/account.get_balance and /transaction.get) and Child Chain (/block.get) to test that passing passing query parameters will return a bad request error.

_For the second set of tests: while these do the job, iI could not think of how to target tests to endpoint.ex. Any insights welcome. Note that we have no GET methods that take input parameters, so no tests written as above.

mix test test/omg_child_chain_rpc/web/controllers/block_test.exs
mix test test/omg_watcher_rpc/web/controllers/block_test.exs
mix test test/omg_watcher_rpc/web/controllers/transaction_test.exs
mix test test/omg_child_chain_rpc/web/plugs/method_param_filter_test.exs
mix test test/omg_watcher_rpc/web/plugs/method_param_filter_test.exs

Thanks to @mederic-p who implemented the logic right before his baby was born. I just added a few tests.

[kalouo]

Hi all, I just had a chat with @thec00n and there are a few things where we could use more experienced eyes:

In endpoint.ex:

    parsers: [:urlencoded, :multipart, :json],
    pass: ["*/*"],

@mederic-p changed to (child chain):

    parsers: [:urlencoded, :json],
    pass: [],

@mederic-p changed to (watcher):

   parsers: [:json],
   pass: [],

It looks fine in the sense that we want the endpoints to only process valid JSON, but I'm not sure if there's something else to consider here, and why :urlencoded stays in the child chain endpoint.ex file.

Would appreciate any insights you have there!

[coveralls]

Coverage decreased (-0.03%) to 77.341% when pulling ce14a71 on 1411-filter-params-http-method into 91cb67f on master.

[InoMurko]

@unnawut pls review!

[InoMurko]

pls remove .tool_versions, distillery, and try if parsers: [:urlencoded, :json], works only with parsers: [:json],

[kalouo]

yep sorry mistake, intended to push only changes to endpoint.

[thec00n]

LGTM

[unnawut]

:mindblown: I wouldn't have thought of checking Connection modules. Thanks you two!

[kalouo]

Thanks to @InoMurko for that one!