Fix swapped AuthorityTypeDefault and AuthorityTypeMultiTenant implementations

[Copilot]

The implementation had AuthorityTypeDefault and AuthorityTypeMultiTenant reversed - single-tenant apps were getting the /common endpoint instead of their tenant-specific endpoint.

// Before: Single-tenant incorrectly used /common
authority := identity.AuthorityConfiguration{
    AuthorityType: identity.AuthorityTypeDefault,
    TenantID: "my-tenant-id",
}
// Produced: https://login.microsoftonline.com/common ❌

// After: Single-tenant correctly uses tenant ID
authority := identity.AuthorityConfiguration{
    AuthorityType: identity.AuthorityTypeDefault,
    TenantID: "my-tenant-id",
}
// Produces: https://login.microsoftonline.com/my-tenant-id ✅

Changes

• identity/authority_configuration.go: Swapped case logic

  • AuthorityTypeDefault: now requires TenantID, returns /{tenantID} endpoint
  • AuthorityTypeMultiTenant: now returns /common endpoint, TenantID optional/ignored
  • Updated comments to clarify single vs multi-tenant usage

• Test updates: Corrected expectations in authority_configuration_test.go and updated test fixtures across 7 files to use AuthorityTypeMultiTenant for generic test scenarios

• Examples: Fixed clientsecret and clientcert examples to use AuthorityTypeDefault

• Documentation: Clarified in README when TenantID is required vs optional

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: Authority configuration for single/multi tenant applications doesn't match documentation</issue_title>
<issue_description>### Describe the bug

In the readme, authority configuration is documented as:

// Multi-tenant application
authority := identity.AuthorityConfiguration{
    AuthorityType: identity.AuthorityTypeMultiTenant,
    TenantID: "common",
}

// Single-tenant application
authority := identity.AuthorityConfiguration{
    AuthorityType: identity.AuthorityTypeDefault,
    TenantID: os.Getenv("AZURE_TENANT_ID"),
}

With AuthorityTypeDefault being used for single tenant applications with a specified tenant id. However the implementation produces an authority url with the common endpoint:

        case AuthorityTypeDefault:
		return "https://login.microsoftonline.com/common", nil
	case AuthorityTypeMultiTenant:
		if a.TenantID == "" {
			return "", fmt.Errorf("tenant ID is required when using multi-tenant authority type")
		}
		return fmt.Sprintf("https://login.microsoftonline.com/%s", a.TenantID), nil

It looks like these cases are the wrong way round.

To Reproduce

1. Create a credentials provider with

	entraid.NewConfidentialCredentialsProvider(
		entraid.ConfidentialCredentialsProviderOptions{
			ConfidentialIdentityProviderOptions: identity.ConfidentialIdentityProviderOptions{
				ClientID:        clientID,
				ClientSecret:    clientSecret,
				CredentialsType: identity.ClientSecretCredentialType,
				Authority: identity.AuthorityConfiguration{
					AuthorityType: identity.AuthorityTypeDefault,
					TenantID:      tenantID,
				},
				Scopes: []string{identity.RedisScopeDefault},
			},
		},
	)

2. Connect to redis

3. Actual behaviour - token is requested with common endpoint https://login.microsoftonline.com/common

Expected behavior

A token is requested using the tenant-specific authority https://login.microsoftonline.com/<tenantID>.

Code Example

Go Version

1.24.0

Package version

v1.0.6

go-redis Version

v9.16.0

Redis Server Version

Azure cache for redis v 6.0

Additional environment details

No response

Additional context

No response</issue_description>

Comments on the Issue (you are @copilot in this section)

@ndyakov Hello @benlings, thank you for reporting this, we will take a look shortly and update the doc.

• Fixes [Bug]: Authority configuration for single/multi tenant applications doesn't match documentation #15

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[ofekshenawa]

LGTM, just fix the failing test