#2986 Meltano should print a warning if any of these are missing from capabilities: (`state`, `discover`, (`catalog` XOR `properties`)) Issue created by MeltyBot Related: • #7265 Migrated from GitLab: https://gitlab.com/meltano/meltano/-/issues/3052 Originally created by @aaronsteers on 2021-11-09 010715 --- There are enough instances of expensive debug operations at this point (most recently today), that I think we should be printing an explicit warning message whenever any of these capabilities are not found in `discovery.yml`: 1. If

state

capability is not declared, then during `meltano elt`: • > Warning: Capability 'state' is not declared for

{tap-name}

. Incremental sync bookmarks will be disabled as a result. 2. If

discover

capability is not declared, then during

meltano elt

and `meltano invoke`: • > Warning: Capability 'discover' is not declared for

{tap-name}

. Proceeding without catalog discovery. • UPDATE (2023-02-03): This rarely is an issue. Discovered catalogs are only really needed if

catalog

is needed, and then specifically for

selection

and

metatata

, or

catalog

overrides in yaml or at the CLI. 3. If neither

catalog

nor

properties

capability is declared, then during

meltano invoke

and `meltano etl`: • > Warning: Capabilities

catalog

and

properties

are both undeclared for

{tap-name}

. Catalog and selection features are disabled. • UPDATE (2023-02-03): • If we don't today fail, we should do so: when

catalog

or

properties

are undefined and the user requests any of the following capabilities:

selection

,

metadata

, or

catalog

overrides. All of these should fail with a clear error message that the operation cannot be performed because

catalog

and/or

properties

is not a supported capability. • Since

selection

and

metadata

overrides require a discovered catalog (or a manually provided one), we should fail if

catalog

is not defined and if a manually-created catalog file is not provided in yaml or at the CLI. 4. During

add --custom

, set default capabilities to

discover,state,catalog

rather than

[]

. 5. Warn if

capabilities

is fully empty, during

meltano invoke

and perhaps also during

meltano install

. • UPDATE (2023-02-03): • Yes, and we should also presume that "no capabilities defined" is equivalent to the default set

[discover,state,catalog]

and not the empty set

[]

. 6.

--dump

commands should fail immediately with a clear message about missing declared capabilities. 1.

--dump=catalog

should fail hard for missing

discover

, should warn for missing

catalog

. 2.

--dump=state

should fail hard for missing

state

. I think these should probably print even when

--log-level=debug

is not set. meltano/meltano