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Basically the simplest assert library you can get.


assert(something truthy)
assert.not(something falsy), expected)
assert.isnt(something, unexpected)

// Deep equality - circular data structures not supported
assert.eq(something, expected)
assert.neq(something, unexpected)

basic-assert is smart enough to display the offending source line. It also works with CoffeeScript (version >= 1.6.2).

How it looks like:

% ./test

Error: Got "[1,2,3]",
Expected:  "[1,2,3,4]"

File: test
Line: 24

assert.eq([1,2,3], [1,2,3,4]);

	   <anonymous> (test:24:8)
	   Module._compile (module.js:456:26)
	   Module._extensions..js (module.js:474:10)
	   Module.load (module.js:356:32)
	   Module._load (module.js:312:12)
	   Module.runMain (module.js:497:10)
	   startup (node.js:119:16)
	   <anonymous> (node.js:901:3)

Normally, assert will just terminate the process when something unexpected happens. If you want it to go on, you can do:

assert.fatal = false


Other JavaScript implementations than V8 are not supported.