This adds a `Livecheck::Options` class, which is intended to house
various configuration options that are set in `livecheck` blocks,
conditionally set by livecheck at runtime, etc. The general idea is
that when we add features involving configurations options (e.g., for
livecheck, strategies, curl, etc.), we can make changes to `Options`
without needing to modify parameters for strategy `find_versions`
methods, `Strategy` methods like `page_headers` and `page_content`,
etc. This is something that I've been trying to improve over the years
and `Options` should help to reduce maintenance overhead in this area
while also strengthening type signatures.
`Options` replaces the existing `homebrew_curl` option (which related
strategies pass to `Strategy` methods and on to `curl_args`) and the
new `url_options` (which contains `post_form` or `post_json` values
that are used to make `POST` requests). I recently added `url_options`
as a temporary way of enabling `POST` support without `Options` but
this restores the original `Options`-based implementation.
Along the way, I added a `homebrew_curl` parameter to the `url` DSL
method, allowing us to set an explicit value in `livecheck` blocks.
This is something that we've needed in some cases but I also intend
to replace implicit/inferred `homebrew_curl` usage with explicit
values in `livecheck` blocks once this is available for use. My
intention is to eventually remove the implicit behavior and only rely
on explicit values. That will align with how `homebrew_curl` options
work for other URLs and makes the behavior clear just from looking at
the `livecheck` block.
Lastly, this removes the `unused` rest parameter from `find_versions`
methods. I originally added `unused` as a way of handling parameters
that some `find_versions` methods have but others don't (e.g., `cask`
in `ExtractPlist`), as this allowed us to pass various arguments to
`find_versions` methods without worrying about whether a particular
parameter is available. This isn't an ideal solution and I originally
wanted to handle this situation by only passing expected arguments to
`find_versions` methods but there was a technical issue standing in
the way. I recently found an answer to the issue, so this also
replaces the existing `ExtractPlist` special case with generic logic
that checks the parameters for a strategy's `find_versions` method
and only passes expected arguments.
Replacing the aforementioned `find_versions` parameters with `Options`
ensures that the remaining parameters are fairly consistent across
strategies and any differences are handled by the aforementioned
logic. Outside of `ExtractPlist`, the only other difference is that
some `find_versions` methods have a `provided_content` parameter but
that's currently only used by tests (though it's intended for caching
support in the future). I will be renaming that parameter to `content`
in an upcoming PR and expanding it to the other strategies, which
should make them all consistent outside of `ExtractPlist`.
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.
This updates the block-handling logic in `Json::versions_from_content`
to naively pass the regex value when the block has two parameters. Up
to now, we have been ensuring that `regex` is not `nil` and this
makes sense with existing usage (the `Crate` strategy's default
block, formulae/cask `strategy` blocks). However, we need to allow a
`nil` `regex` value to make it possible to add an optional `regex`
parameter in the `Pypi::DEFAULT_BLOCK` Proc. This is necessary to
allow the `Pypi` strategy to work with an optional regex from a
`livecheck` block again [without creating an additional
`DEFAULT_BLOCK` variant with a regex parameter].
This setup mimics the `#parse_xml` method that was implemented in the
`Xml` strategy. Isolating the parsing code means that other strategies
can take only what they need from `Json` (i.e., it's not required for
them to use `Json#find_versions`).
This adds a generic `Json` strategy to livecheck that requires a
`strategy` block to operate. This is primarily intended as a
replacement for existing `strategy` blocks in formulae/casks that
use `JSON#parse`, as it allows us to internalize/standardize that
boilerplate while improving error-handling.
Additionally, future strategies that parse JSON data can use the
`Json#find_versions` method instead of having to reinvent the wheel
(similar to how we currently have a number of strategies that
leverage `PageMatch#find_versions`).
