underscore.assert

🔨 Plugin for Underscore.js: add _.assert(), which simplify checking states

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Usage

Installation:

npm install underscore.assert

var _ = require("underscore");
var assert = require("underscore.assert");
_.mixin({ assert: assert });

_.assert(typeof fn === "function", "*fn* should be function"); // throws AssertionError
_.assert(list.length > 0, "*list* should contains any value"); // throws ONLY when list is empty
_.assert(false); // => throw `AssertionError`
_.assert.ErrorConstructor = MyCustomError;
_.assert(false); // => throw `MyCustomError`

Example

Instead of this:

function isUrl(url) {
    if (typeof url === "string") {
        throw new Error("URL should be a *string* value");
    }

    // ... URL validation
}

... you can that:

function isUrl(url) {
    _.assert(typeof url === "string", "URL should be a *string* value");
    // ... URL validation
}

Proposals

• This is not for specs files in project...
• This is not instead of Jasmine or any test framework...
• This is inline code for testing production code!

License

The MIT License @ 2013