Prepare params before action calling

[icebob]

It can be used to prepare the incoming params (e.g. unwrapping the input) before calling the action.

Example
Define the prepareContextParams method.

Signature: prepareContextParams(params, actionName, context)

// api.service.js
module.exports = {
    name: "api",

    mixins: [
        // Gateway
        ApiGateway,

        // GraphQL Apollo Server
        ApolloService({}),
    ],
    methods: {
        prepareContextParams(params, actionName) {
            if (actionName.endsWith(".replace" && params.input) {
                return params.input;
            }
            return params;
        },
    },
});

//greeter.service.js
module.exports = {
    name: "greeter",

    actions: {
        replace: {
            graphql: {
                input: `input GreeterInput {
                    name: String!
                }`,
                mutation: "replace(input: GreeterInput!): String",
            },
            handler(ctx) {
                return `Hello ${ctx.params.name}`; // no need `input`
            },
        },
    }
}

[shawnmcknight]

LGTM!