This is useful for seeing when formulae are deleted if they are going to
leave behind any formulae that depend on them.

As a result, if there are any formulae returned return a non-zero/failed
exit status.

Also update command specifications to match descriptions.

This is a temporary measure until:

- #1862 is merged
- I can a test on `brew uses` against every formula in the official
  taps to verify that exceptions are no longer raised.

…rmulae in recursive dependency expansion""

This reverts commit dc9819b8.

Fixes #1848 by sharing recursive dependency resolution between
dependencies and requirements.

Coincidentally, this also fixes the errors introduced by #1784 that
necessitated it being reverted in #1797.

Fixes #1776.

If any known formula had a dependency on an untapped tap,
Formula#recursive_dependencies would throw an exception, which would be
caught by the outer exception handler, causing the rest of the
dependencies for that formula to be skipped and incomplete output to be
generated.

To fix this, I added a check to avoid analysing the dependencies of
formulae from uninstalled taps.

Additionally, I removed the aforementioned outer exception handler added
in 5fdb89ae, because the only other
place that should be capable of throwing such an exception is the
statement that was surrounded by another wider exception handler in
Homebrew/legacy-homebrew#40682.

For example, `brew deps libass --skip-recommended` shouldn't print
harfbuzz because, even though libass builds with harfbuzz when harfbuzz
is not skipped, we asked to skip recommended, of which harfbuzz is one.

The corresponding change is made for `brew uses` as well.

Thanks to Xu Cheng for contributing the code. Any errors are mine.

Closes #129.

Signed-off-by: ilovezfs <ilovezfs@icloud.com>

Also add options to include optional/build deps and an option
to skip recommended deps.

Closes Homebrew/legacy-homebrew#50066.

Closes Homebrew/homebrew#42354.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Fixes Homebrew/homebrew#40636.

Closes Homebrew/homebrew#39906.

Signed-off-by: Xu Cheng <xucheng@me.com>

This means e.g. `elixir` will show up as using `erlang`.

`ARGV.flag?` = `ARGV.include?` + `ARGV.switch?`

Closes Homebrew/homebrew#36727.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Also add support to `brew uses` to ignore build or optional dependencies.

Closes Homebrew/homebrew#36154.
Closes Homebrew/homebrew#36656.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Dependency names are prefixed with the tap location, therefore
dependency names do not match formula names. We convert dependencies
into formulas to ensure proper name checking.

Closes Homebrew/homebrew#35058.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

`brew uses foo bar` is supposed to return the intersection of formulae
that use foo and bar. However, this was broken by changes made to
support requirements that can coerce to regular dependencies.

With that option iterate only over `Formula.installed`, otherwise
iterate over `Formula`. This is faster than iterating over all the
formulae and checking if it's installed.

Fixes Homebrew/homebrew#27259.
Closes Homebrew/homebrew#27295.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Closes Homebrew/homebrew#24145.

Closes Homebrew/homebrew#23758.

Fixes Homebrew/homebrew#20819.

Fixes Homebrew/homebrew#17074.
Closes Homebrew/homebrew#17075.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Deprecated Formula.all, replaced usage with more appropriate enumerable options. Just check out how much nicer `brew audit` runs now.

Closes Homebrew/homebrew#8870.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>