Fix dialyzer warnings #72
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Fixes Dialyzer warning: The variable X__V can never match since previous clauses completely covered the type 'ok'
X__X::'dummy' can never succeed in test_command_support(Command)
eredis_cluster:qp/1 calls query/4 which can return {error, no_connection}
This fixes a dialyzer warning in eredis_cluster_tests "pipeline":
{'error', 'no_connection'} can never match the type [{'error','invalid_cluster_command'
| 'no_connection' | 'tcp_closed' | bitstring()} | {'ok','undefined' | bitstring()}]
qa/1 and qa/2 return a list of what qw/2 returns, i.e redis_result()
The pattern {'ok', [ExpectedKey | _]} can never match the type
[{'error','invalid_cluster_command' | 'no_connection' | 'tcp_closed' | bitstring()} | {'ok','undefined' | bitstring()}] |
{'error','invalid_cluster_command' | 'no_connection' | 'tcp_closed' | bitstring()} | {'ok','undefined' | bitstring()}
This makes sure we run dialyzer on testcode during development and in CI.
include/eredis_cluster.hrl
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| @@ -6,10 +6,11 @@ | |||
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| -type redis_error_result() :: Reason::bitstring() | no_connection | |||
| | invalid_cluster_command | tcp_closed. | |||
| -type redis_success_result() :: Result::bitstring() | undefined. | |||
| -type redis_success_result() :: bitstring() | [bitstring()] | undefined. | |||
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Where bitstring() (any multiple of bits) is used in these types, it should really be binary() (a multiple of 8 bits).
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Sounds reasonable, but I got stuck when looking into why the change was done in 071b73b.
Maybe it was in early development stages and was then just kept? Can an EVAL return anything else in Redis?
Looking at eredis v1.0.8, used at the time of the change, it states binary() in the return_value() and no bitstring() mentioned in the eredis code either. Sure looks like we should change this.
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EVAL can return RESP data, like any other redis command. It's not even possible to receive parts of a byte over TCP.
Possibly some other spec used bitstring() which gave some warning when it was used with binary(). Do you know if there were any occurrences of bitstring prior to that change?
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No bitstrings can be found in the repo prior to that change.
From OTP-26 the `unknown function or type` warning is on by default. Since dialyzer is now run from the test profile the test-applications are also needed in the PLT, but only in the test profile.
A bitstring() is any multiple of bits while binary() is a multiple of 8 bits. Since RESP is a binary protocol which uses control sequences encoded in standard ASCII, i.e. 8 bits, the type binary() is the proper type to use.
Run dialyzer on the test profile during make dialyzer, and in CI runs.
This PR fixes all dialyzer warnings found in the rebar3 test profile.
Fixes #71