setting default output file name

[linzhp]

When the mocks are in they own package, the gomock rule can be feeded into a go_library rule like this:

gomock(
    name = "rosetta_mock",
    interfaces = ["Client"],
    library = ":go_default_library",
    package = "rosettamock",
    out = "mocks.go",
)

go_library(
    name = "go_mock_library",
    srcs = [":rosetta_mock"],
    importpath = "mock/go-rosetta/rosetta",
    visibility = ["//visibility:public"],
    deps = [
        "@com_github_golang_mock//gomock:go_default_library",
    ],
)

In this case, the out parameter is not necessary. Furthermore, it will cause Gazelle to add mocks.go into go_default_library unless we exclude it using # gazelle:exclude explicitly. This PR sets a default value to the out parameter, so we don't need to specify it when we don't use it directly.

[jmhodges]

Hm, I'm worried about this one because there's no way for folks to know what to include in their other targets to use this one.

[jmhodges]

Do you have any ideas on how to solve that?

[linzhp]

The gomock rule can be feeded into a go_library rule like this:

gomock(
    name = "rosetta_mock",
    interfaces = ["Client"],
    library = ":go_default_library",
    package = "rosettamock",
)

go_library(
    name = "go_mock_library",
    srcs = [":rosetta_mock"],
    importpath = "mock/go-rosetta/rosetta",
    visibility = ["//visibility:public"],
    deps = [
        "@com_github_golang_mock//gomock:go_default_library",
    ],
)

[jmhodges]

Right! If we can get a README update in this patch, that'd be cool!

[linzhp]

@jmhodges I updated the README. Can you take another look?