# package-same-directory

Source: https://apigenie.pl/docs/linter/protobuf/rules/package-same-directory

This rule checks whether all the files of a package are in the same directory.

## Rule Details

A package spread over several directories is hard to find, and code generators that map
directories to packages of the generated code, like the Go one, split it into several packages
that cannot see each other.

The `package-same-directory` rule looks for other files that declare the same package as the
linted file but are in another directory. If there are some, it reports:

`Package '<package>' is also declared in other directories: <directories>`

where `<directories>` lists each other directory once, as `'<directory>' (<file name>)` with
the absolute path of the directory and the name of one of its files. The issue is reported at
the package declaration.

The rule can only compare the files the linter knows about: the files being linted, the other
`.proto` files in their directories, and the files these import, directly or indirectly. A file
of the package that none of them reaches is not seen. Files that cannot be read, for example
because of syntax errors, or because they are proto2 or editions files, are ignored.

Files without a package are not checked.

## Configuration

This rule has no options.

## Examples

**Good**. The files of `acme.pets.v1` are all in `acme/pets/v1`. `acme/pets/v1/pet.proto`:

```proto
syntax = "proto3";

package acme.pets.v1;

import "acme/pets/v1/owner.proto";

message Pet {
  string name = 1;
  Owner owner = 2;
}
```

and `acme/pets/v1/owner.proto`:

```proto
syntax = "proto3";

package acme.pets.v1;

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

**Bad**. The same `pet.proto` imports `acme/pets/v1/owners/owner.proto`, which declares the same
package in a subdirectory:

```proto
syntax = "proto3";

package acme.pets.v1;

import "acme/pets/v1/owners/owner.proto";

message Pet {
  string name = 1;
  Owner owner = 2;
}
```

With the project in `/work`, the linter reports, in `pet.proto`:

`Package 'acme.pets.v1' is also declared in other directories: '/work/acme/pets/v1/owners' (owner.proto)`

## When Not to Use It

You may disable this rule if your build tools and code generators do not map directories to
packages, and you deliberately split large packages into several directories.

## Compatibility

This rule is compatible with proto3 files. proto2 and editions files are rejected by the reader
and are not linted. The rule reads the other files of the package: the other files in the
directories of the linted files, and the imported files, found in the import paths and in the
directories above the importing file.