From 7454e5ae49b90e9d0b73fcc1430e236e58006957 Mon Sep 17 00:00:00 2001
From: Liam Cervante <liam.cervante@hashicorp.com>
Date: Fri, 11 Oct 2024 07:59:30 +0000
Subject: [PATCH] backport of commit d7f1d5b5953ef6afcac00e669f22fd1718b25180

---
 internal/genconfig/generate_config.go      | 10 +--
 internal/genconfig/generate_config_test.go | 88 ++++++++++++++++++++++
 2 files changed, 90 insertions(+), 8 deletions(-)

diff --git a/internal/genconfig/generate_config.go b/internal/genconfig/generate_config.go
index 44387e19c72a..5843c88b3e37 100644
--- a/internal/genconfig/generate_config.go
+++ b/internal/genconfig/generate_config.go
@@ -6,11 +6,11 @@ package genconfig
 import (
 	"encoding/json"
 	"fmt"
-	"regexp"
 	"sort"
 	"strings"
 
 	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
 	"github.com/hashicorp/hcl/v2/hclwrite"
 	"github.com/zclconf/go-cty/cty"
 	ctyjson "github.com/zclconf/go-cty/cty/json"
@@ -20,12 +20,6 @@ import (
 	"github.com/hashicorp/terraform/internal/tfdiags"
 )
 
-var (
-	// whitespace is a regular expression that matches one or more whitespace
-	// characters.
-	whitespace = regexp.MustCompile(`\s+`)
-)
-
 // GenerateResourceContents generates HCL configuration code for the provided
 // resource and state value.
 //
@@ -592,7 +586,7 @@ func ctyCollectionValues(val cty.Value) []cty.Value {
 func hclEscapeString(str string) string {
 	// TODO: Replace this with more complete HCL logic instead of the simple
 	// go workaround.
-	if whitespace.MatchString(str) {
+	if !hclsyntax.ValidIdentifier(str) {
 		return fmt.Sprintf("%q", str)
 	}
 	return str
diff --git a/internal/genconfig/generate_config_test.go b/internal/genconfig/generate_config_test.go
index 12e3c9642fc4..a1392326773a 100644
--- a/internal/genconfig/generate_config_test.go
+++ b/internal/genconfig/generate_config_test.go
@@ -686,6 +686,94 @@ resource "tfcoremock_sensitive_values" "values" {
       value = "underscores"
     }
   }
+}`,
+		},
+		"simple_map_with_periods_in_keys": {
+			schema: &configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"map": {
+						Type:     cty.Map(cty.String),
+						Optional: true,
+					},
+				},
+			},
+			addr: addrs.AbsResourceInstance{
+				Module: addrs.RootModuleInstance,
+				Resource: addrs.ResourceInstance{
+					Resource: addrs.Resource{
+						Mode: addrs.ManagedResourceMode,
+						Type: "testing_resource",
+						Name: "resource",
+					},
+					Key: addrs.NoKey,
+				},
+			},
+			provider: addrs.LocalProviderConfig{
+				LocalName: "testing",
+			},
+			value: cty.ObjectVal(map[string]cty.Value{
+				"map": cty.MapVal(map[string]cty.Value{
+					"key.with.periods":     cty.StringVal("periods"),
+					"key_with_underscores": cty.StringVal("underscores"),
+				}),
+			}),
+			expected: `resource "testing_resource" "resource" {
+  map = {
+    "key.with.periods"   = "periods"
+    key_with_underscores = "underscores"
+  }
+}`,
+		},
+		"nested_map_with_periods_in_keys": {
+			schema: &configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"map": {
+						NestedType: &configschema.Object{
+							Attributes: map[string]*configschema.Attribute{
+								"value": {
+									Type:     cty.String,
+									Optional: true,
+								},
+							},
+							Nesting: configschema.NestingMap,
+						},
+						Optional: true,
+					},
+				},
+			},
+			addr: addrs.AbsResourceInstance{
+				Module: addrs.RootModuleInstance,
+				Resource: addrs.ResourceInstance{
+					Resource: addrs.Resource{
+						Mode: addrs.ManagedResourceMode,
+						Type: "testing_resource",
+						Name: "resource",
+					},
+					Key: addrs.NoKey,
+				},
+			},
+			provider: addrs.LocalProviderConfig{
+				LocalName: "testing",
+			},
+			value: cty.ObjectVal(map[string]cty.Value{
+				"map": cty.MapVal(map[string]cty.Value{
+					"key.with.periods": cty.ObjectVal(map[string]cty.Value{
+						"value": cty.StringVal("periods"),
+					}),
+					"key_with_underscores": cty.ObjectVal(map[string]cty.Value{
+						"value": cty.StringVal("underscores"),
+					}),
+				}),
+			}),
+			expected: `resource "testing_resource" "resource" {
+  map = {
+    "key.with.periods" = {
+      value = "periods"
+    }
+    key_with_underscores = {
+      value = "underscores"
+    }
+  }
 }`,
 		},
 	}