all_asserts

A crate for multiple types of asserts that don't exist in the standard library

Rationale

There are several kinds of problems that I had faced while writing tests, especially when writing comparator tests. The output from the existing macros, were providing vague outputs while debugging which made me write this crate. I had created an RFC, but neverthless it was rejected as there were not enough use cases. I am not too sure about others, but I find myself writing multiple tests that frequently make use of these assert macros.

Importing and using

Add this to your Cargo.toml :

all_asserts = "*"

And now you can use the asserts wherever you like! If you want to make it available all across your crate, in your lib.rs or main.rs, add the following:

#[macro_use]
extern crate all_asserts;

Examples

An example using assert_range! :

use all_asserts::assert_range;
fn main() {
  assert_range!(10..20, 20);
}

This outputs something like:

thread 'main' panicked at 'assertion failed:
`20 is not in range of 10..20` - it should have been in this range, src/main.rs:292:5

Another example:

use all_asserts::{assert_range, assert_nrange};
fn main() {
  assert_range!(1.0..=2.0, 1.5);
  // You can also add a debug message if the assertion fails
  assert_nrange!(
    1.0..=2.0, 1.5, "Oops! 1.5 is in the interval [1.0,2.0]"
  );
}

This outputs:

thread 'main' panicked at 'assertion failed: `1.5 is in range of 1.0..2.0` - it should not have been in this range: Oops! 1.5 is in the interval [1.0,2.0]', src/main.rs:295:5

An example using assert_lt! :

thread 'main' panicked at 'assertion failed: `(left < right) but here (left >= right)`
  left: `100` ,
 right: `200` ', src/main.rs:79:5

Isn't that much better than what the current macros provide? Well, I'll leave you to decide!

Available macros

The name of the assert pretty much tells you everything:

• assert_gt!(a, b) -> Will panic if a is not greater than b
• assert_ge!(a, b) -> Will panic if a is not greater than or equal to b
• assert_lt!(a, b) -> Will panic if a is not less than b
• assert_le!(a, b) -> Will panic if a is not greater than or equal to b
• assert_range!((x..y), b) -> Will panic if b is not within the range [x, y)
• assert_nrange!((x..y), b) -> Will panic if b is within the range [x, y)
• assert_near!(a, b, e) -> Will panic if b is not within +/- e of a; i.e. b is within the range [a - e, a + e]
• assert_true!(a) -> Will panic if a is not true
• assert_false!(a) -> Will panic if a is not false

debug_* variants of the macros are also available, which only work on builds with debug assertions enabled (usually builds produced by running cargo build or cargo test ).

Building

Simply run:

$ git clone https://github.com/ohsayan/all_asserts.git
$ cd all_asserts
$ cargo build

And for testing:

$ cargo test

Contributing

Your welcome to!

"No man is an island!"

And I always stick to that belief! Please help me out in better formatting the output to make debugging easier. If you find an issue, go ahead a create one! (All doubts, questions and ideas are welcome)

License

This project is licensed under the Apache-2.0 License.