Add acceptance tests for how provider handles billing_project arguments

.changelog/11610.txt

@@ -0,0 +1,3 @@
+```release-note:none
+
+```

google/fwprovider/framework_provider_billing_project_test.go

@@ -0,0 +1,155 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+package fwprovider_test
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
+	"github.com/hashicorp/terraform-provider-google/google/acctest"
+)
+
+// TestAccFwProvider_billing_project is a series of acc tests asserting how the PF provider handles billing_project arguments
+// It is PF specific because the HCL used provisions PF-implemented resources
+// It is a counterpart to TestAccSdkProvider_billing_project
+func TestAccFwProvider_billing_project(t *testing.T) {
+	testCases := map[string]func(t *testing.T){
+		// Configuring the provider using inputs
+		"config takes precedence over environment variables":                                           testAccFwProvider_billing_project_configPrecedenceOverEnvironmentVariables,
+		"when billing_project is unset in the config, environment variables are used in a given order": testAccFwProvider_billing_project_precedenceOrderEnvironmentVariables, // GOOGLE_BILLING_PROJECT
+
+		// Schema-level validation
+		"when billing_project is set to an empty string in the config the value isn't ignored and results in an error": testAccFwProvider_billing_project_emptyStringValidation,
+
+		// Usage
+		// Usage test cases are implemented in a Beta-only way
+	}
+
+	for name, tc := range testCases {
+		// shadow the tc variable into scope so that when
+		// the loop continues, if t.Run hasn't executed tc(t)
+		// yet, we don't have a race condition
+		// see https://github.com/golang/go/wiki/CommonMistakes#using-goroutines-on-loop-iterator-variables
+		tc := tc
+		t.Run(name, func(t *testing.T) {
+			tc(t)
+		})
+	}
+}
+
+func testAccFwProvider_billing_project_configPrecedenceOverEnvironmentVariables(t *testing.T) {
+	acctest.SkipIfVcr(t) // Test doesn't interact with API
+
+	billingProject := "my-billing-project-id"
+
+	// ensure all possible billing_project env vars set; show they aren't used instead
+	t.Setenv("GOOGLE_BILLING_PROJECT", billingProject)
+
+	providerBillingProject := "foobar"
+
+	context := map[string]interface{}{
+		"billing_project": providerBillingProject,
+	}
+
+	acctest.VcrTest(t, resource.TestCase{
+		// No PreCheck for checking ENVs
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccFwProvider_billing_project_inProviderBlock(context),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("data.google_provider_config_plugin_framework.default", "billing_project", providerBillingProject),
+				)},
+		},
+	})
+}
+
+func testAccFwProvider_billing_project_precedenceOrderEnvironmentVariables(t *testing.T) {
+	acctest.SkipIfVcr(t) // Test doesn't interact with API
+	/*
+		These are all the ENVs for billing_project
+		GOOGLE_BILLING_PROJECT
+
+		GOOGLE_CLOUD_QUOTA_PROJECT - NOT used by provider, but is in client libraries we use
+	*/
+
+	GOOGLE_BILLING_PROJECT := "GOOGLE_BILLING_PROJECT"
+	GOOGLE_CLOUD_QUOTA_PROJECT := "GOOGLE_CLOUD_QUOTA_PROJECT"
+
+	context := map[string]interface{}{}
+
+	acctest.VcrTest(t, resource.TestCase{
+		// No PreCheck for checking ENVs
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		Steps: []resource.TestStep{
+			{
+				// GOOGLE_BILLING_PROJECT is used if set
+				PreConfig: func() {
+					t.Setenv("GOOGLE_BILLING_PROJECT", GOOGLE_BILLING_PROJECT) //used
+					t.Setenv("GOOGLE_CLOUD_QUOTA_PROJECT", GOOGLE_CLOUD_QUOTA_PROJECT)
+				},
+				Config: testAccFwProvider_billing_project_inEnvsOnly(context),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckResourceAttr("data.google_provider_config_plugin_framework.default", "billing_project", GOOGLE_BILLING_PROJECT),
+				),
+			},
+			{
+				// GOOGLE_CLOUD_QUOTA_PROJECT is NOT used here
+				PreConfig: func() {
+					t.Setenv("GOOGLE_BILLING_PROJECT", "")
+					t.Setenv("GOOGLE_CLOUD_QUOTA_PROJECT", GOOGLE_CLOUD_QUOTA_PROJECT) // NOT used
+				},
+				Config: testAccFwProvider_billing_project_inEnvsOnly(context),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckNoResourceAttr("data.google_provider_config_plugin_framework.default", "billing_project"),
+				),
+			},
+		},
+	})
+}
+
+func testAccFwProvider_billing_project_emptyStringValidation(t *testing.T) {
+	acctest.SkipIfVcr(t) // Test doesn't interact with API
+
+	billingProject := "my-billing-project-id"
+
+	// ensure all billing_project env vars set
+	t.Setenv("GOOGLE_BILLING_PROJECT", billingProject)
+
+	context := map[string]interface{}{
+		"billing_project": "", // empty string used
+	}
+
+	acctest.VcrTest(t, resource.TestCase{
+		// No PreCheck for checking ENVs
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		Steps: []resource.TestStep{
+			{
+				Config:      testAccFwProvider_billing_project_inProviderBlock(context),
+				PlanOnly:    true,
+				ExpectError: regexp.MustCompile("expected a non-empty string"),
+			},
+		},
+	})
+}
+
+// testAccFwProvider_billing_project_inProviderBlock allows setting the billing_project argument in a provider block.
+// This function uses data.google_provider_config_plugin_framework because it is implemented with the plugin-framework
+func testAccFwProvider_billing_project_inProviderBlock(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+provider "google" {
+	billing_project = "%{billing_project}"
+}
+
+data "google_provider_config_plugin_framework" "default" {}
+`, context)
+}
+
+// testAccFwProvider_billing_project_inEnvsOnly allows testing when the billing_project argument
+// is only supplied via ENVs
+func testAccFwProvider_billing_project_inEnvsOnly(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+data "google_provider_config_plugin_framework" "default" {}
+`, context)
+}