Require rule sources from current working directory to be explicitly included

[BernieWhite]

In v1 when calling PSRule cmdlets without -Path and -Module parameters, rule sources from the current working directory $PWD are automatically included.

Including $PWD is problematic in some scenarios such as build pipelines when rule sources may be stored in temporary paths such as out/.

Now that the default recommend path .ps-rule/ for standalone rules is automatically included also including $PWD is not required.

From v2 onwards, $PWD should not be included unless -Path . or -Path $PWD is explicitly specified.

[ArmaanMcleod]

@BernieWhite Considering the new behaviour from #610, this would mean that sources loaded from -Path would have to come after modules.

I would still expect module sources to be preferred by default:

Import-Module .\out\modules\PSRule
Import-Module .\tests\PSRule.Tests\TestModule\
cd .\tests\PSRule.Tests\TestModule\
Get-PSRuleHelp

Name                                ModuleName               Synopsis
----                                ----------               --------
M1.Rule1                            TestModule               Synopsis en-AU.
M1.Rule2                            TestModule               This is the default
M1.YamlTestName                     TestModule               This is an example YAML rule.

But if we are only explicit with -Path, we only get loose files

Get-PSRuleHelp -Path $PWD

Name                                ModuleName               Synopsis
----                                ----------               --------
M1.Rule1                                                     This is the default
M1.Rule2                                                     This is the default
M1.YamlTestName                                              A YAML rule for testing

If we also include -Module, we expect modules to be preferred:

Get-PSRuleHelp -Path $PWD -Module TestModule

WARNING: A rule with the same name 'M1.Rule1' already exists.
WARNING: A rule with the same name 'M1.Rule2' already exists.
WARNING: A rule with the same name 'M1.YamlTestName' already exists.

Name                                ModuleName               Synopsis
----                                ----------               --------
M1.Rule1                            TestModule               Synopsis en-AU.
M1.Rule2                            TestModule               This is the default
M1.YamlTestName                     TestModule               This is an example YAML rule.

Is that correct?

[BernieWhite]

@ArmaanMcleod We still want the behaviour from #610 to be true. More specifically if you run any command such as Get-PSRule we want to change the default behaviour of finding rules recursively from $PWD to $PWD/.ps-rule/.

i.e. if you cd docs\scenarios\azure-resources and run Get-PSRule you would get:

RuleName                            ModuleName                 Synopsis
--------                            ----------                 --------
appServicePlan.MinInstanceCount                                App Service Plan has multiple instances
appServicePlan.MinPlan                                         Use at least a Standard App Service Plan
appServiceApp.ARRAffinity                                      Disable client affinity for stateless services
appServiceApp.UseHTTPS                                         Use HTTPS only
storageAccounts.UseHttps                                       Configure storage accounts to only accept encrypted traffic i.e. HTTPS/SMB
storageAccounts.UseEncryption                                  Use at-rest storage encryption

The current behaviour is complex.

• If no module is specified, rules are discovered from $PWD and $PWD/.ps-rule/ by default. Based on the Include.Path option default. Help
• If any module is specified, rules are discovered from the module base paths and $PWD/.ps-rule/ by default.

The new behaviour should be, don't include $PWD at all unless it is specified, which could be by:

• Manually specifying -Path $PWD on cmdlets.
• Specifying the source: '.' property on GitHub Actions or Azure Pipelines task, which effectively explicitly sets -Path $PWD.
• Setting the Include.Path and including ..

In terms of preferring modules, we should use the same behaviour that if the source is already loaded from a module which is done first then is should not be loaded again as a loose/ standalone source.