MochaUI.md

Mocha UI

feature(title, reducer, path?, fn)

Wraps all tests of a reducer and related action creators and selectors. Initializes a mock store which is used to test the module. Contains multiple scenarios. Based on Mocha's describe.

Arguments

• title (String): Name of the redux module.
• reducer (Function): Main reducer of the module.
• path (Array or String, optional): Path in state where the reducer's state is supposed to be (when selectors require it). May be either a string or an array of strings. The reducer is wrapped in combineReducers from redux-immutable, so that the reducer's state can be accessed using state.getIn(path) (or state.get(path) when it is simle a string).
• fn (Function): Comprising scenarios.

scenario(title, fn)

Wraps a single given-when-then test scenario. Must contain exactly one given followed by zero or more whens, followed by zero or more thens or parametrized thens, optionally followed by a result. Based on Mocha's context.

Arguments

• title (String): Scenario description.
• fn (Function): Comprising tests.

given(title?)

Specifies initial state of a scenario. May be a resulting state of previous test (see result).

Arguments

• title (String, optional): References previous result call. When empty, uses initial state of the reducer.

when(title, actionCreator, ...params)

Applies single action. Action creator and its arguments are specified separately, so that we can catch errors in action creator.

Example

when('search query is set', setQuery, 'Bonehunters');

applies the action setQuery('Bonehunters').

Arguments

• title (String): Description of what the action does.
• actionCreator (Function): Action creator function.
• params (Any, spread): Action creator arguments.

when(title, [actionCreator, ...params], [actionCreator, ...params], ...)

Applies multiple actions. Each action creator and its arguments are specified in a single array, e.g.:

when('search query is set and changed', [setQuery, 'Bridgeburners'], [setQuery, 'Bonehunters']);

Arguments

• title (String): Description of what the action does.
• actionCreator (Function): Action creator function.
• params (Any, spread): Action creator arguments.

then(title, selector, ...params, assertion)

Specifies assertion on state. A selector is used to retrieve value from state and the assertion is called on it. You can use any existing assertion library.

Example

then('character can be retrieved', getCharacter, 0, (result) => result.should.exist());

roughly translates to

it('character can be retrieved', () => {
    getCharacter(state, 0).should.exist();
});

Arguments

• title (String): Assertion description.
• selector (Function): Selector function used to retrieve value from state.
• params (Any, spread): Selector arguments.
• assertion (Function): Callback function which is called on the retrieved values.

thenP(title, selector, [...params1], [...params2], ..., assertion)

Parametric assertion. Uses one selector with several parameter sets and then checks them with parametrized assertion.

Example

then(
    'all characters can be retrieved', 
    getCharacter, 
    [0], [1], [2], [3], 
    (result, id) => result.should.equal(character[id]),
);

roughly translates to

it('all characters can be retrieved', () => {
    getCharacter(state, 0).should.equal(character[0]);
    getCharacter(state, 1).should.equal(character[1]);
    getCharacter(state, 2).should.equal(character[2]);
    getCharacter(state, 3).should.equal(character[3]);
});

Arguments

• title (String): Assertion description.
• selector (Function): Selector function used to retrieve value from state.
• [params1] (Any, spread): array of parameters for single selector and assertion call.
• assertion(result, ...params) (Function): Parametrized assertion. Called with selector call results and parameters with which the selector was called.

result(title)

Can be used to store resulting state of a scenario under a string identifier. It can be later used as an initial state for a scenario using given.

Arguments

• title (String): String identifier of the state. Used in given to use the state.