First, import the eet module:

var eet = require("users/aazuspan/eet:eet");

Then write your first test using eet.test. This function takes a test description (to help you keep track) and a callable function to run during testing.

eet.test("Check runMyCalculation", function() {
    var value = runMyCalculation();
    if (value != 42) throw new Error("That should have equaled 42!");

As you can see, you can write your own tests from scratch by checking conditions and throwing errors, but eet has an assert module to handle common checks. Here’s the same test using the assert module.

eet.test("Check runMyCalculation", function() {
    var value = runMyCalculation();
    eet.assert.equal(value, 42);

Once you’ve built all your tests, run them and display the results with;

All tests passed!

API Reference


  • test(description, function) : Register a function for testing.
  • run(pattern) : Run tests and report the results. An optional regex pattern can be used to only run matching tests.


Assertions test a specific condition and thrown an error if the condition fails. Most assertions take one or two values to compare and an optional message that will override the default error message. If you’re familiar with the Node.js assert module, the eet assertions will look very familiar, as they are generally identicial. Note that eet assertions work with client-side data only, so use getInfo to compare Earth Engine objects.

  • assert.ok(value, message) : Value is truthy.
  • assert.notOk(value, message) : Value is falsy.
  • assert.equal(actual, expected, message) : Values are equal ==.
  • assert.notEqual(actual, expected, message) : Values are not equal !=.
  • assert.strictEqual(actual, expected, message) : Values are strictly equal ===.
  • assert.strictNotEqual(actual, expected, message) : Values are strictly not equal !==.
  • assert.exists(value, message) : Value is not null or undefined.
  • assert.notExists(value, message) : Value is null or undefined.
  • assert.match(string, regex, message) : String matches regex pattern.
  • assert.doesNotMatch(string, regex, message) : String does not match regex pattern.
  •, array, message) : Value is in array.
  • assert.notIn(value, array, message) : Value is not in array.
  • assert.throws(fn, errorLike, errMsgMatcher, message) : Function throws error. Specify an Error-like (e.g. ReferenceError) to only match specific error types. Specify a regex message pattern to only match errors with a matching error message.
  • : Automatically fail.


View Github