Support ISO months

elm.json

@@ -15,6 +15,6 @@
         "elm/time": "1.0.0 <= v < 2.0.0"
     },
     "test-dependencies": {
-        "elm-explorations/test": "1.0.0 <= v < 2.0.0"
+        "elm-explorations/test": "2.0.0 <= v < 3.0.0"
     }
 }

src/Iso8601.elm

@@ -419,6 +419,7 @@ monthYearDayInMs =
                 |. symbol "-"
                 |= paddedInt 2
             , paddedInt 2
+            , succeed 1
             ]
         -- DD
         |> Parser.andThen yearMonthDay

tests/Example.elm

@@ -3,9 +3,9 @@ module Example exposing (knownValues, reflexive)
 import Expect
 import Fuzz
 import Iso8601
+import Json.Decode exposing (decodeString, errorToString)
 import Test exposing (..)
 import Time
-import Json.Decode exposing (decodeString, errorToString)
 
 
 knownValues : Test
@@ -99,11 +99,20 @@ knownValues =
             \_ ->
                 Iso8601.toTime "2019-05-30T06:30"
                     |> Expect.equal (Ok (Time.millisToPosix 1559197800000))
+        , test "toTime supports yyyy-mm format with time attached" <|
+            \_ ->
+                Iso8601.toTime "2022-01T00:00"
+                    |> Expect.equal (Ok (Time.millisToPosix 1640995200000))
+        , test "toTime supports yyyy-mm format without time attached" <|
+            \_ ->
+                Iso8601.toTime "2022-11"
+                    |> Expect.equal (Ok (Time.millisToPosix 1667260800000))
         , test "decoder returns clearer error for dead ends" <|
             \_ ->
                 case decodeString Iso8601.decoder "2010-09-31T14:29:25.01235Z" of
                     Err error ->
                         Expect.notEqual (errorToString error) "TODO deadEndsToString"
+
                     Ok _ ->
                         Expect.fail "Should fail on dead ends"
         ]