From c10afa3ab506d82cd56e2723b78c829ff416888f Mon Sep 17 00:00:00 2001
From: gruebel <anton.gruebel@gmail.com>
Date: Sun, 17 Nov 2019 15:10:38 +0100
Subject: [PATCH] Add organizations.list_tags_for_resource

---
 IMPLEMENTATION_COVERAGE.md                    |  2 +-
 moto/organizations/models.py                  | 12 ++++++
 moto/organizations/responses.py               |  5 +++
 .../test_organizations_boto3.py               | 41 +++++++++++++++++++
 4 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/IMPLEMENTATION_COVERAGE.md b/IMPLEMENTATION_COVERAGE.md
index d6a4d8174..213775d83 100644
--- a/IMPLEMENTATION_COVERAGE.md
+++ b/IMPLEMENTATION_COVERAGE.md
@@ -4762,7 +4762,7 @@
 - [X] list_policies
 - [X] list_policies_for_target
 - [X] list_roots
-- [ ] list_tags_for_resource
+- [x] list_tags_for_resource
 - [X] list_targets_for_policy
 - [X] move_account
 - [ ] remove_account_from_organization
diff --git a/moto/organizations/models.py b/moto/organizations/models.py
index 2fb0a6656..b5059fe8d 100644
--- a/moto/organizations/models.py
+++ b/moto/organizations/models.py
@@ -455,5 +455,17 @@ class OrganizationsBackend(BaseBackend):
         new_tags = {tag["Key"]: tag["Value"] for tag in kwargs["Tags"]}
         account.tags.update(new_tags)
 
+    def list_tags_for_resource(self, **kwargs):
+        account = next((a for a in self.accounts if a.id == kwargs["ResourceId"]), None)
+
+        if account is None:
+            raise RESTError(
+                "InvalidInputException",
+                "You provided a value that does not match the required pattern.",
+            )
+
+        tags = [{"Key": key, "Value": value} for key, value in account.tags.items()]
+        return dict(Tags=tags)
+
 
 organizations_backend = OrganizationsBackend()
diff --git a/moto/organizations/responses.py b/moto/organizations/responses.py
index 11093bae1..ab01ffb8a 100644
--- a/moto/organizations/responses.py
+++ b/moto/organizations/responses.py
@@ -124,3 +124,8 @@ class OrganizationsResponse(BaseResponse):
         return json.dumps(
             self.organizations_backend.tag_resource(**self.request_params)
         )
+
+    def list_tags_for_resource(self):
+        return json.dumps(
+            self.organizations_backend.list_tags_for_resource(**self.request_params)
+        )
diff --git a/tests/test_organizations/test_organizations_boto3.py b/tests/test_organizations/test_organizations_boto3.py
index 95b115548..27989c276 100644
--- a/tests/test_organizations/test_organizations_boto3.py
+++ b/tests/test_organizations/test_organizations_boto3.py
@@ -618,6 +618,17 @@ def test_tag_resource():
 
     client.tag_resource(ResourceId=account_id, Tags=[{"Key": "key", "Value": "value"}])
 
+    response = client.list_tags_for_resource(ResourceId=account_id)
+    response["Tags"].should.equal([{"Key": "key", "Value": "value"}])
+
+    # adding a tag with an existing key, will update the value
+    client.tag_resource(
+        ResourceId=account_id, Tags=[{"Key": "key", "Value": "new-value"}]
+    )
+
+    response = client.list_tags_for_resource(ResourceId=account_id)
+    response["Tags"].should.equal([{"Key": "key", "Value": "new-value"}])
+
 
 @mock_organizations
 def test_tag_resource_errors():
@@ -635,3 +646,33 @@ def test_tag_resource_errors():
     ex.response["Error"]["Message"].should.contain(
         "You provided a value that does not match the required pattern."
     )
+
+
+@mock_organizations
+def test_list_tags_for_resource():
+    client = boto3.client("organizations", region_name="us-east-1")
+    client.create_organization(FeatureSet="ALL")
+    account_id = client.create_account(AccountName=mockname, Email=mockemail)[
+        "CreateAccountStatus"
+    ]["AccountId"]
+    client.tag_resource(ResourceId=account_id, Tags=[{"Key": "key", "Value": "value"}])
+
+    response = client.list_tags_for_resource(ResourceId=account_id)
+
+    response["Tags"].should.equal([{"Key": "key", "Value": "value"}])
+
+
+@mock_organizations
+def test_list_tags_for_resource_errors():
+    client = boto3.client("organizations", region_name="us-east-1")
+    client.create_organization(FeatureSet="ALL")
+
+    with assert_raises(ClientError) as e:
+        client.list_tags_for_resource(ResourceId="000000000000")
+    ex = e.exception
+    ex.operation_name.should.equal("ListTagsForResource")
+    ex.response["Error"]["Code"].should.equal("400")
+    ex.response["Error"]["Message"].should.contain("InvalidInputException")
+    ex.response["Error"]["Message"].should.contain(
+        "You provided a value that does not match the required pattern."
+    )