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.
This inlines the `PRIORITY` and `#match?` logic from `PageMatch`
into `Sparkle` instead of subclassing `PageMatch`. `Sparkle` doesn't
really make sense as a subclass of `PageMatch` (since it functions
in a completely different manner), so it's better to simply copy
over these parts of `PageMatch`. This also helps to separate the
strategies, so any changes to `PRIORITY` or `#match?` in `PageMatch`
won't affect `Sparkle`.
