fixup! Add Fuzz.filterMap

elm-explorations · Jan 20, 2024 · 099edd4 · 099edd4
1 parent 55c4cd2
commit 099edd4
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Showing 2 changed files with 21 additions and 6 deletions.
diff --git a/src/Fuzz.elm b/src/Fuzz.elm
@@ -9,11 +9,10 @@ module Fuzz exposing
     , array, maybe, result
     , bool, unit, order, weightedBool
     , oneOf, oneOfValues, frequency, frequencyValues
-    , constant, invalid, filter
+    , constant, invalid, filter, filterMap
     , map, map2, map3, map4, map5, map6, map7, map8, andMap
     , andThen, lazy, sequence, traverse
     , fromGenerator
-    , filterMap
     )
 
 {-| This is a library of _fuzzers_ you can use to supply values to your fuzz
@@ -1336,23 +1335,33 @@ a risk of infinite loop depending on the predicate), you can use this pattern:
 
 -}
 filter : (a -> Bool) -> Fuzzer a -> Fuzzer a
-filter predicate = filterMap (\a -> if predicate a then Just a else Nothing)
+filter predicate =
+    filterMap
+        (\a ->
+            if predicate a then
+                Just a
+
+            else
+                Nothing
+        )
+
 
 {-| A fuzzer that applies a function returning a Maybe on a given fuzzer and
 output values, as List.filterMap does.
 
 Example usage:
 
-    type UnicodeNonLetter = UnicodeNonLetter Char
+    type UnicodeNonLetter
+        = UnicodeNonLetter Char
 
     fromChar : Char -> Maybe UnicodeNonLetter
     fromChar c =
         if (c |> Unicode.isLower |> not) && (c |> Unicode.isUpper |> not) then
             UnicodeNonLetter |> Just
+
         else
             Nothing
 
-
     fuzz : Fuzzer UnicodeNonLetter
     fuzz =
         Fuzz.char |> Fuzz.filterMap fromChar

diff --git a/tests/src/FuzzerTests.elm b/tests/src/FuzzerTests.elm
@@ -1145,8 +1145,14 @@ fuzzerSpecificationTests =
                     intsNotDivBy5 : Fuzzer Int
                     intsNotDivBy5 =
                         Fuzz.int
-                            |> Fuzz.filterMap (\i -> if isDivBy5 i then Nothing else Just i)
+                            |> Fuzz.filterMap
+                                (\i ->
+                                    if isDivBy5 i then
+                                        Nothing
 
+                                    else
+                                        Just i
+                                )
                 in
                 [ rejects "impossible func (always Nothing)"
                     (Fuzz.int |> Fuzz.filterMap (\_ -> Nothing))