fix: adjust default custom headers variable (#47)

README.md

@@ -241,7 +241,7 @@ Available targets:
 | <a name="input_basic_auth_credentials"></a> [basic\_auth\_credentials](#input\_basic\_auth\_credentials) | The credentials for basic authorization for the Amplify app | `string` | `null` | no |
 | <a name="input_build_spec"></a> [build\_spec](#input\_build\_spec) | The [build specification](https://docs.aws.amazon.com/amplify/latest/userguide/build-settings.html) (build spec) for the Amplify app.<br/>If not provided then it will use the `amplify.yml` at the root of your project / branch. | `string` | `null` | no |
 | <a name="input_context"></a> [context](#input\_context) | Single object for setting entire context at once.<br/>See description of individual variables for details.<br/>Leave string and numeric variables as `null` to use default value.<br/>Individual variable settings (non-null) override settings in context object,<br/>except for attributes, tags, and additional\_tag\_map, which are merged. | `any` | <pre>{<br/>  "additional_tag_map": {},<br/>  "attributes": [],<br/>  "delimiter": null,<br/>  "descriptor_formats": {},<br/>  "enabled": true,<br/>  "environment": null,<br/>  "id_length_limit": null,<br/>  "label_key_case": null,<br/>  "label_order": [],<br/>  "label_value_case": null,<br/>  "labels_as_tags": [<br/>    "unset"<br/>  ],<br/>  "name": null,<br/>  "namespace": null,<br/>  "regex_replace_chars": null,<br/>  "stage": null,<br/>  "tags": {},<br/>  "tenant": null<br/>}</pre> | no |
-| <a name="input_custom_headers"></a> [custom\_headers](#input\_custom\_headers) | The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html | `string` | `""` | no |
+| <a name="input_custom_headers"></a> [custom\_headers](#input\_custom\_headers) | The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html | `string` | `null` | no |
 | <a name="input_custom_rules"></a> [custom\_rules](#input\_custom\_rules) | The custom rules to apply to the Amplify App | <pre>list(object({<br/>    condition = optional(string)<br/>    source    = string<br/>    status    = optional(string)<br/>    target    = string<br/>  }))</pre> | `[]` | no |
 | <a name="input_delimiter"></a> [delimiter](#input\_delimiter) | Delimiter to be used between ID elements.<br/>Defaults to `-` (hyphen). Set to `""` to use no delimiter at all. | `string` | `null` | no |
 | <a name="input_description"></a> [description](#input\_description) | The description for the Amplify app | `string` | `null` | no |

docs/terraform.md

@@ -42,7 +42,7 @@
 | <a name="input_basic_auth_credentials"></a> [basic\_auth\_credentials](#input\_basic\_auth\_credentials) | The credentials for basic authorization for the Amplify app | `string` | `null` | no |
 | <a name="input_build_spec"></a> [build\_spec](#input\_build\_spec) | The [build specification](https://docs.aws.amazon.com/amplify/latest/userguide/build-settings.html) (build spec) for the Amplify app.<br/>If not provided then it will use the `amplify.yml` at the root of your project / branch. | `string` | `null` | no |
 | <a name="input_context"></a> [context](#input\_context) | Single object for setting entire context at once.<br/>See description of individual variables for details.<br/>Leave string and numeric variables as `null` to use default value.<br/>Individual variable settings (non-null) override settings in context object,<br/>except for attributes, tags, and additional\_tag\_map, which are merged. | `any` | <pre>{<br/>  "additional_tag_map": {},<br/>  "attributes": [],<br/>  "delimiter": null,<br/>  "descriptor_formats": {},<br/>  "enabled": true,<br/>  "environment": null,<br/>  "id_length_limit": null,<br/>  "label_key_case": null,<br/>  "label_order": [],<br/>  "label_value_case": null,<br/>  "labels_as_tags": [<br/>    "unset"<br/>  ],<br/>  "name": null,<br/>  "namespace": null,<br/>  "regex_replace_chars": null,<br/>  "stage": null,<br/>  "tags": {},<br/>  "tenant": null<br/>}</pre> | no |
-| <a name="input_custom_headers"></a> [custom\_headers](#input\_custom\_headers) | The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html | `string` | `""` | no |
+| <a name="input_custom_headers"></a> [custom\_headers](#input\_custom\_headers) | The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html | `string` | `null` | no |
 | <a name="input_custom_rules"></a> [custom\_rules](#input\_custom\_rules) | The custom rules to apply to the Amplify App | <pre>list(object({<br/>    condition = optional(string)<br/>    source    = string<br/>    status    = optional(string)<br/>    target    = string<br/>  }))</pre> | `[]` | no |
 | <a name="input_delimiter"></a> [delimiter](#input\_delimiter) | Delimiter to be used between ID elements.<br/>Defaults to `-` (hyphen). Set to `""` to use no delimiter at all. | `string` | `null` | no |
 | <a name="input_description"></a> [description](#input\_description) | The description for the Amplify app | `string` | `null` | no |

variables.tf

@@ -139,7 +139,7 @@ variable "iam_service_role_actions" {
 variable "custom_headers" {
   type        = string
   description = "The custom headers for the Amplify app, allows specifying headers for every HTTP response. Must adhere to AWS's format: https://docs.aws.amazon.com/amplify/latest/userguide/custom-headers.html"
-  default     = ""
+  default     = null
 }
 
 variable "custom_rules" {