assert_cli "next" preview presenting assert_{cmd,fs}

[killercup]

• assert_cmd based on predicates
• assert_fs
• first draft of nice guide

[killercup]

@epage said:

the main blocking issue for assert_fs / assert_cmd is now out for review assert-rs/predicates-rs#60

Once that is in:

• Split up predicates crate
• Create a "0.9" of the predicates crates, assert_fs, and assert_cmd
• Encourage people to do an API review before going 1.0?

[epage]

Looking at the issues to 1.0, I'd be comfortable releasing a 0.9 as soon as my last PR is in.

• https://github.com/assert-rs/assert_fs/milestone/1
• https://github.com/assert-rs/assert_cmd/milestone/1
• https://github.com/assert-rs/predicates-rs/milestone/3

EDIT: Added predicates

[killercup]

Updated the title to reflect the current goal.

@epage, all that's missing is a blob of text describing what this is and why people should get excited about it. Can you write a few lines?

[epage]

assert_cmd and assert_fs simplify integration testing of your crate with

• Ability to execute your bin and examples
• Setup temp directories for your program to mutate
• Assert on the result of your program and the resulting filesystem changes

[killercup]

Thanks! :)