return not found for not verified contract for token read_contract

[ayrat555]

Motivation

fixes

Request: GET /smart_contracts?hash=0x77fe30b2cf39245267c0a5084b66a560f1cf9e1f
** (exit) an exception was raised:
    ** (BadMapError) expected a map, got: nil
        (elixir) lib/map.ex:451: Map.get(nil, :abi, nil)
        (explorer) lib/explorer/smart_contract/reader.ex:170: Explorer.SmartContract.Reader.read_only_functions/1
        (block_scout_web) lib/block_scout_web/controllers/smart_contract_controller.ex:11: BlockScoutWeb.SmartContractController.index/2
        (block_scout_web) lib/block_scout_web/controllers/smart_contract_controller.ex:1: BlockScoutWeb.SmartContractController.action/2
        (block_scout_web) lib/block_scout_web/controllers/smart_contract_controller.ex:1: BlockScoutWeb.SmartContractController.phoenix_controller_pipeline/2
        (block_scout_web) lib/block_scout_web/endpoint.ex:1: BlockScoutWeb.Endpoint.instrument/4
        (phoenix) lib/phoenix/router.ex:275: Phoenix.Router.__call__/1
        (phoenix) lib/phoenix/router/route.ex:39: Phoenix.Router.Route.call/2

Changelog

• return not found for not verified contract for token read_contract

[coveralls]

Pull Request Test Coverage Report for Build bf1d4c9c-ef52-4db1-b802-f4ea65e932b2

• 4 of 4 (100.0%) changed or added relevant lines in 2 files are covered.
• 13 unchanged lines in 5 files lost coverage.
• Overall coverage decreased (-0.2%) to 76.451%

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Files with Coverage Reduction	New Missed Lines	%
apps/indexer/lib/indexer/fetcher/token.ex	1	80.0%
apps/indexer/lib/indexer/fetcher/token_balance.ex	2	87.88%
apps/indexer/lib/indexer/block/catchup/bound_interval_supervisor.ex	3	85.19%
apps/indexer/lib/indexer/fetcher/token_instance.ex	3	0.0%
apps/indexer/lib/indexer/block/fetcher.ex	4	86.75%

Totals
Change from base Build 7eac4942-59b6-478f-ba79-37b9eb8c6f07:	-0.2%
Covered Lines:	5295
Relevant Lines:	6926

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💛 - Coveralls

[pasqu4le]

I think this can be moved into the else of the with with the other not_found(conn) by moving the if into the with, maybe like so:

  false <- is_nil(address.smart_contract)

or something like that.

[vbaranov]

@ayrat555

[ayrat555]

@vbaranov @pasqu4le done