Go type of variables object.

[dmitshur]

The variables object, which is optionally present as part of queries and mutations, must be valid JSON object.

By encoding/json rules, we can use a Go struct or a Go map type, which will then get JSON encoded into a JSON object.

During initial development, I started with the following signature for Query:

func (c *Client) Query(ctx context.Context, q interface{}, variables interface{}) error

And usage looked like this:

variables := struct {
	RepositoryOwner githubql.String
	RepositoryName  githubql.String
	IssueNumber     githubql.Int
}{githubql.String(repo.Owner), githubql.String(repo.Repo), githubql.Int(id)}
err = client.Query(ctx, &v, variables)

However, having to define a new struct for each variables object seemed less optimal than using a map. Mostly because the Go syntax has you repeating the fields and the field values twice, as well as doing type conversions.

Compare to the syntax when using a map:

func (c *Client) Query(ctx context.Context, q interface{}, variables map[string]interface{}) error

variables := map[string]interface{}{
	"RepositoryOwner": githubql.String(repo.Owner),
	"RepositoryName":  githubql.String(repo.Repo),
	"IssueNumber":     githubql.Int(id),
}
err = client.Query(ctx, &v, variables)

That seems easier to write and read, so that was the API decision I went with for the initial commit.

[dmitshur]

This decision has been made in 78a7455.

Closing this issue. It exists here for posterity, so the decision and the reasoning behind it can be seen, and if needed, revisited in the future.