Developer Notes

Go Upgrades

The mockery project supports the most recent TWO stable Go versions. Testing matrices will only run on the two most recent stable Go versions. However, given the Go backwards-compatibility guarantee, it's very likely projects built off of older Go 1.x syntax will continue to work in perpetuity.

Go Syntax Updates

When Go releases new syntax, there are two approaches that the mockery project will take:

Mockery does not need to interact with the new syntax

In such cases, the mockery project only needs to upgrade its golang.org/x/tools dependency. This is necessary for the parsing step to simply not fail if it encounters new syntax. If mockery does not need to interact or understand this syntax, this dependency upgrade is likely all that's needed.

Take for example the problems mentioned [here] when mockery upgraded to go 1.24 in its go.mod file. In this situation, the project maintainers wanted to allow mockery to not crash when it parses syntax containing generic type alias syntax. However, the project did not parse this syntax, so the only thing we needed to do was upgrade golang.org/x/tools.

Mockery does need to interact with the new syntax

This situation was encountered in Go 1.18 when generics were introduced. In this case, the project needed to be upgraded to go 1.18 because mockery now had to directly parse and interpret generic types through the go/ast package. This was needed in conjunction with an upgrade of golang.org/x/tools that handles the actual parsing into go/ast data.

It's possible in future versions of Go that only the toolchain directive needs to be upgraded to allow mockery to use a more recent go/ast package. The purposes of the go directive is supposed to inform the compiler what features of the Go language the module uses in its own syntax, so in this case as long as mockery does not itself use generics, it can parse generic type information from other projects without needing to pin its go directive to the relevant version.