From 39b458231690254704a504be16dc19922cd712fc Mon Sep 17 00:00:00 2001
From: marshallmain <55718608+marshallmain@users.noreply.github.com>
Date: Mon, 6 Apr 2020 16:28:35 -0400
Subject: [PATCH] Merge reusable location lists when merging a custom schema
 with an ECS schema (#751)

---
 CHANGELOG.next.md                   |  2 ++
 scripts/schema_reader.py            | 12 ++++++++++--
 scripts/tests/test_schema_reader.py | 12 ++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.next.md b/CHANGELOG.next.md
index c7b2eb9f30..f53d23abff 100644
--- a/CHANGELOG.next.md
+++ b/CHANGELOG.next.md
@@ -48,6 +48,8 @@ Thanks, you're awesome :-) -->
 
 #### Improvements
 
+* Add support for reusing offical fieldsets in custom schemas. #751
+
 #### Deprecated
 
 
diff --git a/scripts/schema_reader.py b/scripts/schema_reader.py
index 806efcc54f..01a8766a29 100644
--- a/scripts/schema_reader.py
+++ b/scripts/schema_reader.py
@@ -85,7 +85,7 @@ def schema_set_fieldset_prefix(schema):
 
 def schema_fields_as_dictionary(schema):
     """Re-nest the array of field names as a dictionary of 'fieldname' => { field definition }"""
-    field_array = schema.pop('fields')
+    field_array = schema.pop('fields', [])
     schema['fields'] = {}
     for order, field in enumerate(field_array):
         field['order'] = order
@@ -114,7 +114,15 @@ def merge_schema_fields(a, b):
                 raise ValueError('Schemas unmergeable: type {} does not match type {}'.format(a_type, b_type))
             elif a_type not in ['object', 'nested']:
                 print('Warning: dropping field {}, already defined'.format(key))
-            elif 'fields' in b[key]:
+                continue
+            # reusable should only be found at the top level of a fieldset
+            if 'reusable' in b[key]:
+                a[key].setdefault('reusable', {})
+                a[key]['reusable']['top_level'] = a[key]['reusable'].get(
+                    'top_level', False) or b[key]['reusable']['top_level']
+                a[key]['reusable'].setdefault('expected', [])
+                a[key]['reusable']['expected'].extend(b[key]['reusable']['expected'])
+            if 'fields' in b[key]:
                 a[key].setdefault('fields', {})
                 merge_schema_fields(a[key]['fields'], b[key]['fields'])
 
diff --git a/scripts/tests/test_schema_reader.py b/scripts/tests/test_schema_reader.py
index 7cc6e2729f..f94a571adc 100644
--- a/scripts/tests/test_schema_reader.py
+++ b/scripts/tests/test_schema_reader.py
@@ -257,6 +257,10 @@ def test_merge_schema_fields(self):
         fieldset1 = {
             'test_fieldset': {
                 'name': 'test_fieldset',
+                'reusable': {
+                    'top_level': False,
+                    'expected': ['location1, location2']
+                },
                 'fields': {
                     'test_field1': {
                         'field_details': {
@@ -278,6 +282,10 @@ def test_merge_schema_fields(self):
         fieldset2 = {
             'test_fieldset': {
                 'name': 'test_fieldset',
+                'reusable': {
+                    'top_level': True,
+                    'expected': ['location3, location4']
+                },
                 'fields': {
                     'test_field1': {
                         'field_details': {
@@ -299,6 +307,10 @@ def test_merge_schema_fields(self):
         expected = {
             'test_fieldset': {
                 'name': 'test_fieldset',
+                'reusable': {
+                    'top_level': True,
+                    'expected': ['location1, location2', 'location3, location4']
+                },
                 'fields': {
                     'test_field1': {
                         'field_details': {