# package-version-suffix

Source: https://apigenie.pl/docs/linter/protobuf/rules/package-version-suffix

This rule checks whether the last component of the package name of a Protobuf file is a
version, such as `v1` or `v1beta2`.

## Rule Details

Versioned packages let a new, incompatible version of an API live next to the old one: the
messages and services of `acme.pets.v2` do not clash with those of `acme.pets.v1`, neither in
the Protobuf namespace nor in the generated code.

The `package-version-suffix` rule reports `Package '<name>' should end with a version
component, e.g. v1 or v1beta1` when the last component of the package name is not a version. A
version component is:

- `v` followed by a major version that does not start with `0`: `v1`, `v2`, `v10`,
- optionally followed by a stability, `alpha` or `beta`, itself optionally followed by a
  number: `v1alpha`, `v1beta2`,
- optionally with a point release between the major version and the stability: `v1p1alpha`,
  `v1p2beta3`. A point release requires a stability, so `v1p1` is not a version,
- or followed by `test` and any lowercase letters and digits: `v2test`, `v1testfoo`.

These are the versions buf accepts. Components such as `v0`, `V1`, `version1`, `v1final` and
`v1p1test` are not versions.

Files without a package are not checked; see the `package-defined` rule.

The rule is part of the `strict` and `all` rulesets.

## Configuration

This rule has no options.

## Examples

**Good**.

```proto
syntax = "proto3";

package acme.pets.v1beta1;

message Pet {
  string name = 1;
}
```

**Bad**. The linter reports `Package 'acme.pets' should end with a version component, e.g.
v1 or v1beta1`.

```proto
syntax = "proto3";

package acme.pets;

message Pet {
  string name = 1;
}
```

## When Not to Use It

You may disable this rule if your APIs are versioned in another way, for example by the
repository or the service name, or if the files are internal and never published.

## Compatibility

This rule is compatible with proto3 files. proto2 and editions files are rejected by the reader
and are not linted.