Allow validation blocks in inputs

test/fixtures/hclvalidate/valid/validation-block/main.tf

@@ -0,0 +1,10 @@
+variable "example_var" {
+  type        = string
+  description = "A variable that requires validation."
+  default     = "test"
+
+  validation {
+    condition     = length(var.example_var) > 0
+    error_message = "The example_var must not be empty."
+  }
+}

test/fixtures/hclvalidate/valid/validation-block/terragrunt.hcl

@@ -0,0 +1 @@
+// intentionally blank

tf/tf.go

@@ -179,16 +179,25 @@ func ModuleVariables(modulePath string) ([]string, []string, error) {
 		},
 	}
 
+	varsAttributesSchema := &hcl.BodySchema{
+		Attributes: []hcl.AttributeSchema{
+			{
+				Name:     "default",
+				Required: false,
+			},
+		},
+	}
+
 	varsContent, _, contentDiags := body.PartialContent(varsSchema)
 	allDiags = append(allDiags, contentDiags...)
 	optional, required := []string{}, []string{}
 
 	for _, b := range varsContent.Blocks {
 		name := b.Labels[0]
-		attributes, attrDiags := b.Body.JustAttributes()
+		varBodyContent, _, attrDiags := b.Body.PartialContent(varsAttributesSchema)
 
 		allDiags = append(allDiags, attrDiags...)
-		if _, ok := attributes["default"]; ok {
+		if _, ok := varBodyContent.Attributes["default"]; ok {
 			optional = append(optional, name)
 		} else {
 			required = append(required, name)