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elm-doc-test Build Status

Verify examples in your docs.


$ npm i elm-test -g
$ npm i elm-doc-test -g
$ elm-test init


$ touch tests/elm-doc-test.json

elm-doc-test.json contains information on which files contain verified examples and where to find them.

  "root": "../src",
  "tests": [

It's recommended to add ./tests/Doc to your .gitignore.

Writing Verified Examples

Verified examples look like normal code examples in doc-comments.
Code needs to be indented by 4 spaces. You can specify the expected result of an expression, by adding a comment --> (the > is important) and an expected expression.

{-| returns the sum of two int.
    -- You can write the expected result on the next line,
    add 41 1
    --> 42
    -- or on the same line.
    add 3 3 --> 6
add : Int -> Int -> Int
add =
You can write examples on multiple lines.
{-| reverses the list
        [ 41
        , 1
    --> [ 1
    --> , 41
    --> ]
    rev [1, 2, 3]
        |> toString
        |> String.join ""
    --> "321"
rev : List a -> List a
rev =

You can specify imports, if you want to use a module or a special test util.

    import Dict
    myWeirdFunc (Dict.fromList [(1, "a"), (2, "b")]) [2, 1]
    --> "ba"

Running DocTests

elm-doc-test only converts your doc-tests into elm-tests. You have to use elm-test in order to run them.

$ elm-doc-test && elm-test tests/Doc/Main.elm

By default the first command creates the tests at tests/Doc/. If you want to have them at a custom location use the --output argument (e.g. elm-doc-test --output my/custom/path/ will create the tests at my/custom/path/Doc/).

Also by default the first command looks for the config file at tests/elm-doc-test.json. If you want it to load a specific config file use the --config argument (e.g. elm-doc-test --config my/custom/path/elm-doc-test.json will read the config from my/custom/path/elm-doc-test.json).


You can run the examples using:

npm start