elm-diff

A diff implementation for Elm.

This is a fork of jinjor/elm-diff, adding the possibility of considering two items similar.

The algorithm

This library implements Wu's O(NP) algorithm. It shares the idea with Myers's O(ND) algorithm, but is much faster in some cases.

LICENSE

BSD-3-Clause

Using Diff.diffLinesWith with elm-test

You can use this function to pretty print differences when comparing Strings in elm-test.

expectEqualMultiline : String -> String -> Expect.Expectation
expectEqualMultiline exp actual =
    if exp == actual then
        Expect.pass

    else
        let
            header : String
            header =
                Ansi.Color.fontColor Ansi.Color.blue "Diff from expected to actual:"
        in
        Expect.fail
            (header
                ++ "\n"
                ++ (Diff.diffLinesWith
                        (Diff.defaultOptions
                            |> Diff.ignoreLeadingWhitespace
                        )
                        exp
                        actual
                        |> Diff.ToString.diffToString { context = 4, color = True }
                   )
            )