Between this commit and the previous one, this brings test coverage
for `Livecheck::Strategy` up to 98.18% line coverage and 97.22%
branch coverage. The only uncovered areas are some Sorbet `params`
calls (which I'm not sure how to cover) and a conditional `break` in
`page_headers` that will be refactored away in the future.
The increased coverage is primarily in areas that weren't covered
before because they call methods that make network requests. I worked
around this with stubs and doubles, so we can test this code to some
degree. I plan to expand this approach to other areas in livecheck
that aren't covered for the same reason and that should significantly
increase test coverage (along with some other test improvements that
I have lined up).
livecheck currently doesn't support `POST` requests but it wasn't
entirely clear how best to handle that. I initially approached it as
a `Post` strategy but unfortunately that would have required us to
handle response body parsing (e.g., JSON, XML, etc.) in some fashion.
We could borrow some of the logic from related strategies but we would
still be stuck having to update `Post` whenever we add a strategy for
a new format.
Instead, this implements `POST` support by borrowing ideas from the
`using: :post` and `data` `url` options found in formulae. This uses
a `post_form` option to handle form data and `post_json` to handle
JSON data, encoding the hash argument for each into the appropriate
format. The presence of either option means that curl will use a
`POST` request.
With this approach, we can make a `POST` request using any strategy
that calls `Strategy::page_headers` or `::page_content` (directly or
indirectly) and everything else works the same as usual. The only
change needed in related strategies was to pass the options through
to the `Strategy` methods.
For example, if we need to parse a JSON response from a `POST`
request, we add a `post_data` or `post_json` hash to the `livecheck`
block `url` and use `strategy :json` with a `strategy` block. This
leans on existing patterns that we're already familiar with and
shouldn't require any notable maintenance burden when adding new
strategies, so it seems like a better approach than a `Post` strategy.
Valid `strategy` block return types currently vary between
strategies. Some only accept a string whereas others accept a string
or array of strings. [`strategy` blocks also accept a `nil` return
(to simplify early returns) but this was already standardized across
strategies.]
While some strategies only identify one version by default (where a
string is an appropriate return type), it could be that a strategy
block identifies more than one version. In this situation, the
strategy would need to be modified to accept (and work with) an
array from a `strategy` block.
Rather than waiting for this to become a problem, this modifies all
strategies to standardize on allowing `strategy` blocks to return a
string or array of strings (even if only one of these is currently
used in practice). Standardizing valid return types helps to further
simplify the mental model for `strategy` blocks and reduce cognitive
load.
This commit extracts related logic from `#find_versions` into
methods like `#versions_from_content`, which is conceptually similar
to `PageMatch#page_matches` (renamed to `#versions_from_content`
for consistency). This allows us to write tests for the related code
without having to make network requests (or stub them) at this point.
In general, this also helps to better align the structure of
strategies and how the various `#find_versions` methods work with
versions.
There's still more planned work to be done here but this is a step
in the right direction.
