A TestContext represents an Elm program, a current state for that program, and a log of any errors that have occurred while simulating interaction with the program.

• To create a TestContext, see the create* functions below.
• To advance the state of a TestContext, see Simulating user input, and Directly sending Msgs
• To assert on the resulting state of a TestContext, see Final assertions

Creates a TestContext from the parts of a standard Html.program.

See other create* functions below if the program you want to test uses flags or nagivation.

Creates a TestContext from the parts of a standard with flags (Html.programWithFlags).

If your program uses Json.Encode.Value as its flags type, you may find createWithJsonStringFlags useful.

If your program does not use flags, see create.

See other create* functions below if the program you want to test uses nagivation.

A simplified way to create a TestContext for a program that decodes its flags with a JSON decoder.

If your program does not use Json.Encode.Value as its flags type, or you want more control over how the flags are provided in your tests, see createWithFlags.

If your program does not use flags, see create.

See other create* functions below if the program you want to test uses nagivation.

Creates a TestContext from the parts of a standard Html.program and a base URL against which relative URLs can be resolved.

If you don't need to simulate clicking links with relative URLs, prefer create.

If your program uses navigation, see createWithNavigation.

Creates a TestContext from the parts of a Navigation.program.

See other create* functions above and below if the program you want to test uses flags or does not use nagivation.

Creates a TestContext from the parts of a program with navigation and flags (Navigation.programWithFlags).

If your program uses Json.Encode.Value as its flags type, you may find createWithNavigationAndJsonStringFlags useful.

If your program does not use flags, see createWithNavigation.

If your program does not use navigation, see createWithFlags.

A simplified way to create a TestContext for a program with navigation that decodes its flags with a JSON decoder.

If your program does not use Json.Encode.Value as its flags type, or you want more control over how the flags are provided in your tests, see createWithNavigationAndFlags.

If your program does not use flags, see createWithNavigation.

If your program does not use navigation, see createWithJsonStringFlags.

This represents an effect that elm-program-test is able to simulate. When using createWithSimulatedEffects you will provide a function that can translate your programs' effects into SimulatedEffects. (If you do not use a create* function that lets your provide a deconstructEffect : effect -> List SimulatedEffect function, then TestContext will not simulate any HTTP effects for you.)

Creates a TestContext from the parts of a standard Html.program, and lets you provide a deconstructEffect function that lets TestContext simulate HTTP effects (this enables you to use assertHttpRequest).

If you do not need to simulate HTTP requests, you can use create instead.

Simulates clicking a button.

Currently, this function will find and click a <button> HTML node containing the given buttonText.

NOTE: In the future, this function will be generalized to find buttons with accessibility attributes matching the given buttonText.

Simulates clicking a <a href="..."> link.

NOTE: Currently, this function requires that you also provide the expected href. After eeue56/elm-html-test#52 is resolved, a future release of this package will remove the href parameter.

Note for testing single-page apps, if the target <a> tag has an onClick handler, then the message produced by the handler will be processed and the href will not be followed. NOTE: Currently this function cannot verify that the onClick handler sets preventDefault, but this will be done in the future after https://github.com/eeue56/elm-html-test/issues/63 is resolved.

Simulates replacing the text in an input field labeled with the given label.

NOTE: Currently, this function requires that you also provide the field id (which must match both the id attribute of the target input element, and the for attribute of the label element). After eeue56/elm-html-test#52 is resolved, a future release of this package will remove the fieldId parameter.

NOTE: TODO: In the future, this will be generalized to work with labeled textareas as well as labeled input fields. (related to eeue56/elm-html-test#49)

NOTE: In the future, this will be generalized to work with aria accessiblity attributes in addition to working with standard HTML label elements.

If you need to target a <textarea> that does not have a label, see fillInTextarea.

If you need more control over the finding the target element or creating the simulated event, see simulate.

Simulates replacing the text in a <textarea>.

This function expects that there is only one <textarea> in the view. If your view has more than one <textarea>, prefer adding associated <label> elements and use fillIn. If you cannot add <label> elements see within.

If you need more control over the finding the target element or creating the simulated event, see simulate.

Simulates setting the value of a checkbox labeled with the given label.

NOTE: Currently, this function requires that you also provide the field id (which must match both the id attribute of the target input element, and the for attribute of the label element). After eeue56/elm-html-test#52 is resolved, a future release of this package will remove the fieldId parameter.

NOTE: In the future, this will be generalized to work with aria accessiblity attributes in addition to working with standard HTML label elements.

If you need more control over the finding the target element or creating the simulated event, see simulate.

url may be an absolute URL or relative URL

Simulates a custom DOM event.

NOTE: If there is another, more specific function (see Simulating user input that does what you want, prefer that instead, as you will get the benefit of better error messages.

Parameters:

• findTarget: A function to find the HTML element that responds to the event (typically this will be a call to Test.Html.Query.find [ ...some selector... ])
• ( eventName, eventValue ): The event to simulate (see Test.Html.Event "Event Builders")

Focus on a part of the view for a particular operation.

For example, if your view produces the following HTML:

<div>
  <div id="sidebar">
    <button>Submit</button>
  </div>
  <div id="content">
    <button>Submit</button>
  </div>
</div>

then the following will allow you to simulate clicking the "Submit" button in the sidebar (simply using clickButton "Submit" would fail because there are two buttons matching that text):

import Test.Html.Query as Query
import Test.Html.Selector exposing (id)


testContext
    |> TestContext.within
        (Query.find [ id "sidebar" ])
        (TestContext.clickButton "Submit")
    |> ...

A final assertion that checks whether an HTTP request to the specific url and method has been made.

NOTE: You must use createWithSimulatedEffects to create your initial TestContext to be able to use this function.

Advances the state of the TestContext's program by using the TestContext's program's update function with the given msg.

This can be used to simulate events that can only be triggered by commands (Cmd) and subscriptions (Sub) (i.e., that cannot be triggered by user interaction with the view).

NOTE: When possible, you should prefer Simulating user input, as doing so will make your tests more robust to changes in your program's implementation details.

NOTE: If you cannot replace a call to TestContext.upate with simulating user input, when possible you should prefer to use simulateLastEffect.

Simulate the outcome of the last effect produced by the program being tested by providing a function that can convert the last effect into msgs.

The function you provide will be called with the effect that was returned by the most recent call to update or init in the TestContext.

If the function returns Err, then that will cause the TestContext to enter a failure state with the provided message.

If the fuction returns Ok, then the list of msgs will be applied in order via TestContext.update.

A simpler way to assert that a TestContext's view matches a given selector.

expectViewHas [...selector...] is the same as expectView (Test.Html.Query.has [...selector...]).

Makes an assertion about the current state of a TestContext's view.

Makes an assertion about the last effect produced by a TestContext's program.

Make an assertion about the current state of a TestContext's model.

Asserts that the program ended by navigating away to another URL.

shouldHave [...selector...] is equivalent to shouldHaveView (Test.Html.Query.has [...selector...])

shouldNotHave [...selector...] is equivalent to shouldHaveView (Test.Html.Query.hasNot [...selector...])

Validates the the current state of a TestContext's view without ending the TestContext.

Validates the last effect produced by a TestContext's program without ending the TestContext.

Ends a TestContext, reporting any errors that occurred.

NOTE: You should prefer using a final assertion to end your test over using done, as doing so will make the intent of your test more clear.

fail can be used to report custom errors if you are writing your own convenience functions to deal with test contexts.

Example (this is a function that checks for a particular structure in the program's view, but will also fail the TestContext if the expectedCount parameter is invalid):

expectNotificationCount : Int -> TestContext Msg Model effect -> TestContext Msg Model effect
expectNotificationCount expectedCount testContext =
    if expectedCount <= 0 then
        testContext
            |> TestContext.fail "expectNotificationCount"
                ("expectedCount must be positive, but was: " ++ String.fromInt expectedCount)


    else
        testContext
            |> shouldHave
                [ Test.Html.Selector.class "notifications"
                , Test.Html.Selector.text (toString expectedCount)
                ]