elm-review/tests/NoUselessIfTest.elm

module NoUselessIfTest exposing (all)

import Lint.Rules.NoUselessIf exposing (rule)
import Lint.Types exposing (LintError, LintResult, LintRule)
import Test exposing (Test, describe, test)
import TestUtil exposing (expectErrors, ruleTester)


testRule : String -> LintResult
testRule =
    ruleTester rule


error : LintError
error =
    LintError "NoUselessIf" "Useless if expression: It will always evaluate to the same value"


tests : List Test
tests =
    [ test "should not report If expression that has different values in both paths" <|
        \() ->
            testRule "a = if b then c else d"
                |> expectErrors []
    , test "should report If expression that has the same value in both paths" <|
        \() ->
            testRule "a = if b then c else c"
                |> expectErrors [ error ]
    , test "should report If expression that has the same complex value in both paths" <|
        \() ->
            testRule "a = if b then (foo m, bar n p) else (foo m, bar n p)"
                |> expectErrors [ error ]
    ]


all : Test
all =
    describe "NoUselessIf" tests