0.1.3 docs





    Feb 4, 2014

    Bodil Stokke


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    The README below is fetched from the published project artifact. Some relative links may be broken.


    A testing toolkit for ClojureScript, designed for testing asynchronous code.



    Add Error as a development dependency in project.clj:

    :profiles {:dev {:plugins [[org.bodil/lein-error "0.1.2"]]
                     :dependencies [[org.bodil/error "0.1.2"]]}}

    You also need to set up a cljsbuild for compiling your tests. It needs to be called :test, must have :optimizations set to at least :simple, and must have :output-to set. Even if you plan on running the tests on Node, you should not set :target :nodejs.

    :builds {:test {:source-paths ["src" "test"]
                    :compiler {:output-to "js/test.js"
                               :optimizations :simple}}}

    You can define default environments for Error in project.clj; if you don’t, it will default to running only on Node. Available environments are :node, which runs the test suite on Node, and :phantom, which runs it on PhantomJS.

    :error {:environments #{:node :phantom}}



    Tests can be run through Leiningen by executing lein error. You can specify which environments to run the test suite in by giving keyword arguments to lein error, eg. lein error :node :phantom.


    To run the test suite from the REPL, simply ensure that the tests you wish to run are loaded into the REPL, and run (error.test/run-tests).

    For instance, to run Error’s own test suite, start a REPL in Error’s project directory and run the following:

    $ lein trampoline noderepl
    "Type: " :cljs/quit " to quit"
    ClojureScript:cljs.user> (load-file "error/case.cljs")
    ClojureScript:cljs.user> (error.test/run-tests)
    Running 8 tests from 1 namespace in environment node
    8 tests succeeded.

    Writing Tests

    Tests are defined using the test macro. Error is intended for testing asynchronous code, so a function done is provided inside the scope of the test, which must be called when the test is finished. If you forget to call done, the test will eventually time out and fail. Default timeout is set to 10 seconds, but you can specify a custom timeout in a test’s options map, as seen below.

    (ns i.can.has.tests
      (:require-macros [error.macros :refer [test is]])
      (:require [error.test]))
    (test "str should concatenate strings together"
      (is (= "Pinkie Pie" (str "Pinkie" " Pie")))
    (test "should asynchronously complete a test using async code"
      (js/setTimeout #(done) 100))
    (test "str should still concatenate with some test local bindings"
      [pinkie "Pinkie "
       pie "Pie"]
      (is (= "Pinkie Pie" (str pinkie pie)))
    (test {:only :node} "node specific test should only run on node"
      (process/nextTick #(done)))
    (test {:timeout 15000} "should succeed in 14 seconds"
      (js/setTimeout #(done) 14000))
    (test {:expect :fail} "a failing test expected to fail should succeed"
      (is (= 13 37))

    Test Options

    The following options are supported by the test macro:

    • :timeout <number> defines the number of milliseconds a test has to complete before failing with a timeout. Defaults to 10 seconds.
    • :only <environment> takes a set of keywords, or just one keyword, describing which environments the test is valid for. If the test suite is running in a different environment, the test will be skipped. Valid environments are :node and :browser.
    • :ignore true will cause the test to be ignored.
    • :expect <result> redefines a test’s success condition. The argument can be either of the following:
    • :fail expects the test to fail.
    • :timeout expects the test to time out.
    • :error expects the test to result in an exception.
    • Any other value expects the test to result in an exception which satisfies (instance? <value> <exception>). For example, :expect js/TypeError expects the test to throw a TypeError exception.

    Additionally, if the test’s description string starts with the comment character ;, it will be ignored just as if :ignore true were set.


    • Nashorn test runner, perhaps degrading to Rhino on JDK < 8.
    • Watch mode for lein error.


    Copyright 2013 Bodil Stokke

    Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

    Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.