Update tool to handle major version upgrade of release

[tadelesh]

Apply go package rule for major version. Need to use v2/v3/... sub-path for the major version upgrade.

[jhendrixMSFT]

We don't need to do this for the source code, just append it to the module's identity in go.mod.

[RickWinter]

Note, It should be the uncommon case that we do major version updates. If you are expecting this to be the common case we should discuss where and why to see how we can fix the generated code to better handle those cases.

cc: @JeffreyRichter

[jhendrixMSFT]

The common case is bugs in the swagger where types are just incorrectly defined (should have been int but was marked string). We see these all the time and will necessitate breaking changes.

[tadelesh]

Among 13 preview we need to release, there are 7 have breaking changes. I went through all the changelogs and seems all from swagger breaking (e.g., string to enum, type change, remove operation, param name change). I've already hold the v2 beta release for more careful review.

[jhendrixMSFT]

A parameter name change shouldn't be considered breaking. Looks like the tool will need to be updated to handle this.

[tadelesh]

@jhendrixMSFT, among these six v2 version PRs breakings (18227-18232), there is a breaking: string change to modelAsString enum. For other SDK, it will not be a breaking. But it seems if we treat it as enum, the breaking is not avoidable in Go. What do you think?

[jhendrixMSFT]

When you have a single value enum with modelAsString: false it means that the value is considered a constant, and that's how M4 models it. I'm surprised that other languages would model this as an enum as per swagger definition it's not. Can you share a link to an example?

[tadelesh]

When you have a single value enum with modelAsString: false it means that the value is considered a constant, and that's how M4 models it. I'm surprised that other languages would model this as an enum as per swagger definition it's not. Can you share a link to an example?

I mean change from type string to type enum with modelAsString: true.
E.g., for this PR's breaking: KeySource changed from string to enum. The swagger's related PR is here. From the SDK automation result, it seems other SDK has no breaking for such change. It is a little special that this enum only has one value. @ArcturusZhang think, for strongly typed language, it should be a breaking, but none-breaking for other languages. For modelAsString value, I wonder whether it could be defined a string type with a helper function.

[jhendrixMSFT]

I took a look at the swagger PR, and it looks to me that the cross-version breaking change didn't flag this. Is this a bug? For a single value enum, changing from modelAsString: false to modelAsString: true is a breaking change.

CC @mikekistler

[tadelesh]

Close this task as the tool has already updated. The breaking change issues are discussed in the mail thread.