hledger-api doesn't build with swagger2 2.1.5

[felixonmars]

[1 of 1] Compiling Main             ( hledger-api.hs, dist/build/hledger-api/hledger-api-tmp/Main.dyn_o )

hledger-api.hs:220:10: error:
    • Cannot derive Generic-based Swagger Schema for Price
      Price is a mixed sum type (has both unit and non-unit constructors).
      Swagger does not have a good representation for these types.
      Use genericDeclareNamedSchemaUnrestricted if you want to derive schema
      that matches aeson's Generic-based toJSON,
      but that's not supported by some Swagger tools.
    • In the expression:
        Data.Swagger.Internal.Schema.$dmdeclareNamedSchema @Price
      In an equation for ‘declareNamedSchema’:
          declareNamedSchema
            = Data.Swagger.Internal.Schema.$dmdeclareNamedSchema @Price
      In the instance declaration for ‘ToSchema Price’
    |
220 | instance ToSchema Price
    |          ^^^^^^^^^^^^^^

[simonmichael]

Thanks, what GHC version is this ?

[felixonmars]

It's GHC 8.2.1. It builds fine with swagger2 2.1.4.1.

[simonmichael]

Oh right I get you. Thanks.

[simonmichael]

PS we do still need a to fix this for swagger 2.1.5 in the future, help welcome.

[simonmichael]

cf commercialhaskell/stackage#2861

[fizruk]

@simonmichael the error message was designed to guide migration process.

    • Cannot derive Generic-based Swagger Schema for Price
      Price is a mixed sum type (has both unit and non-unit constructors).
      Swagger does not have a good representation for these types.
      Use genericDeclareNamedSchemaUnrestricted if you want to derive schema
      that matches aeson's Generic-based toJSON,
      but that's not supported by some Swagger tools.

Specifically this part:

      Use genericDeclareNamedSchemaUnrestricted ...

So you just need this change:

- instance ToSchema Price
+ instance ToSchema Price where
+   declareNamedSchema = genericDeclareNamedSchemaUnrestricted defaultSchemaOptions

[simonmichael]

Noted, thank you!

[juhp]

2.1.6 is out

[simonmichael]

Reopening this as a reminder to follow through with GetShopTV/swagger2#122 .

[simonmichael]

hledger-api got removed from stackage, remember to re-add it when 1.4 is released.