test: adds unit tests for policy_attachment sub module

Author: nimisha-gj

tests/unit-tests.tftest.hcl

@@ -256,6 +256,7 @@ variables {
 EOF
 }
 
+# Attribute validations for policy module
 run "policy_name_match" {
   command = plan
 
@@ -410,3 +411,64 @@ run "policy_tags_match" {
     error_message = "Tag 'another_key_name' with value 'another_value' is missing or incorrect"
   }
 }
+
+# Attribute validations for policy_attachment module
+run "policy_attachment_policy_id_match" {
+  command = plan
+
+  module {
+    source = "./modules/policy_attachment/"
+  }
+
+  variables {
+    policy_id          = "p-12345678"
+    target_id          = "r-1234"
+    skip_destroy       = true
+    expected_policy_id = "p-12345678"
+  }
+
+  assert {
+    condition     = aws_organizations_policy_attachment.this.policy_id == var.expected_policy_id
+    error_message = "Policy ID mismatch after attachment"
+  }
+}
+
+run "policy_attachment_target_id_match" {
+  command = plan
+
+  module {
+    source = "./modules/policy_attachment/"
+  }
+
+  variables {
+    policy_id          = "p-12345678"
+    target_id          = "r-1234"
+    skip_destroy       = true
+    expected_target_id = "r-1234"
+  }
+
+  assert {
+    condition     = aws_organizations_policy_attachment.this.target_id == var.expected_target_id
+    error_message = "Target ID mismatch after attachment"
+  }
+}
+
+run "policy_attachment_skip_destroy_match" {
+  command = plan
+
+  module {
+    source = "./modules/policy_attachment/"
+  }
+
+  variables {
+    policy_id             = "p-12345678"
+    target_id             = "r-1234"
+    skip_destroy          = true
+    expected_skip_destroy = true
+  }
+
+  assert {
+    condition     = aws_organizations_policy_attachment.this.skip_destroy == var.expected_skip_destroy
+    error_message = "Skip destroy mismatch after attachment"
+  }
+}