@sleepwithcoffee thanks for taking care of that.

Still to ensure best reliability all tests refactor should be done in a way so new tests run with runServerless util. See https://github.com/serverless/serverless/tree/main/test#unit-tests

And as I checked in more detail we can totally remove the validate.test.js file as:

1. Som tests confirm implementation details (we should not write such tests, and we're ok to remove them
2. Stage resolution is already well tested here:

   serverless/test/unit/lib/plugins/aws/provider.test.js

   Lines 760 to 795 in 16dd286

   	describe('#getStage()', () => {
   	it('should default to "dev"', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	});
   	expect(serverless.getProvider('aws').getStage()).to.equal('dev');
   	});
   	it('should allow to override via `provider.stage`', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	configExt: {
   	provider: {
   	stage: 'staging',
   	},
   	},
   	});
   	expect(serverless.getProvider('aws').getStage()).to.equal('staging');
   	});
   	it('should allow to override via CLI `--stage` param', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	options: { stage: 'production' },
   	configExt: {
   	provider: {
   	stage: 'staging',
   	},
   	},
   	});
   	expect(serverless.getProvider('aws').getStage()).to.equal('production');
   	});
   	});

3. Region resolution is already tested here:

   serverless/test/unit/lib/plugins/aws/provider.test.js

   Lines 591 to 626 in 16dd286

   	describe('#getRegion()', () => {
   	it('should default to "us-east-1"', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	});
   	expect(serverless.getProvider('aws').getRegion()).to.equal('us-east-1');
   	});
   	it('should allow to override via `provider.region`', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	configExt: {
   	provider: {
   	region: 'eu-central-1',
   	},
   	},
   	});
   	expect(serverless.getProvider('aws').getRegion()).to.equal('eu-central-1');
   	});
   	it('should allow to override via CLI `--region` param', async () => {
   	const { serverless } = await runServerless({
   	fixture: 'aws',
   	command: 'print',
   	options: { region: 'us-west-1' },
   	configExt: {
   	provider: {
   	region: 'eu-central-1',
   	},
   	},
   	});
   	expect(serverless.getProvider('aws').getRegion()).to.equal('us-west-1');
   	});
   	});

In light of that, I've just removed this test file from the repository: 2e004eb

So, sorry you've taken an effort on that, but at least it moved us into right direction of removing this test file :)