From e9180e4ebde0898abbcb658365740beeb53bce7d Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 12 Aug 2024 15:14:58 -0400
Subject: [PATCH] benchmark for plan eval

---
 internal/terraform/plan_benchmark_test.go | 74 +++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 internal/terraform/plan_benchmark_test.go

diff --git a/internal/terraform/plan_benchmark_test.go b/internal/terraform/plan_benchmark_test.go
new file mode 100644
index 0000000000..b3be27cc40
--- /dev/null
+++ b/internal/terraform/plan_benchmark_test.go
@@ -0,0 +1,74 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package terraform
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform/internal/addrs"
+	"github.com/hashicorp/terraform/internal/configs/configschema"
+	"github.com/hashicorp/terraform/internal/providers"
+	testing_provider "github.com/hashicorp/terraform/internal/providers/testing"
+	"github.com/hashicorp/terraform/internal/states"
+	"github.com/zclconf/go-cty/cty"
+)
+
+// Benchmark that stresses resource instance evaluation during plan
+func BenchmarkPlanLargeCountRefs(b *testing.B) {
+	m := testModuleInline(b, map[string]string{
+		"main.tf": `
+resource "test_resource" "a" {
+  count = 512
+  input = "ok"
+}
+
+resource "test_resource" "b" {
+  count = length(test_resource.a)
+  input = test_resource.a
+}
+
+module "mod" {
+  count = length(test_resource.a)
+  source = "./mod"
+  in = [test_resource.a[count.index].id, test_resource.b[count.index].id]
+}
+
+output out {
+  value = module.mod
+}`,
+		"./mod/main.tf": `
+variable "in" {
+}
+
+output "out" {
+  value = var.in
+}
+`})
+
+	p := new(testing_provider.MockProvider)
+	p.GetProviderSchemaResponse = getProviderSchemaResponseFromProviderSchema(&providerSchema{
+		ResourceTypes: map[string]*configschema.Block{
+			"test_resource": {
+				Attributes: map[string]*configschema.Attribute{
+					"id":    {Type: cty.String, Computed: true},
+					"input": {Type: cty.DynamicPseudoType, Optional: true},
+				},
+			},
+		},
+	})
+
+	ctx := testContext2(b, &ContextOpts{
+		Providers: map[addrs.Provider]providers.Factory{
+			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
+		},
+	})
+
+	b.ResetTimer()
+	for range b.N {
+		_, diags := ctx.Plan(m, states.NewState(), DefaultPlanOpts)
+		if diags.HasErrors() {
+			b.Fatal(diags.Err())
+		}
+	}
+}