From 4477b8ddcd6a77678d1d683cd43af0489fb3261a Mon Sep 17 00:00:00 2001
From: Sam Bostock <sam.bostock@shopify.com>
Date: Tue, 30 Nov 2021 22:58:12 -0500
Subject: [PATCH 1/2] Add test for existing field addition criticality

---
 .../changes/field_added_test.rb               | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 test/lib/graphql/schema_comparator/changes/field_added_test.rb

diff --git a/test/lib/graphql/schema_comparator/changes/field_added_test.rb b/test/lib/graphql/schema_comparator/changes/field_added_test.rb
new file mode 100644
index 0000000..e13d842
--- /dev/null
+++ b/test/lib/graphql/schema_comparator/changes/field_added_test.rb
@@ -0,0 +1,21 @@
+require "test_helper"
+
+class GraphQL::SchemaComparator::Changes::FieldAddedTest < Minitest::Test
+  def test_criticality_is_non_breaking_by_default
+    change = GraphQL::SchemaComparator::Changes::FieldAdded.new(
+      GraphQL::ObjectType.define { name "Type" },
+      GraphQL::Field.define { name "field" },
+    )
+
+    assert change.non_breaking?
+  end
+
+  def test_criticality_is_non_breaking_for_id_field_addition
+    change = GraphQL::SchemaComparator::Changes::FieldAdded.new(
+      GraphQL::ObjectType.define { name "Type" },
+      GraphQL::Field.define { name "id" },
+    )
+
+    assert change.non_breaking?
+  end
+end

From 1ed191e22b68c1da5c95d2763eb3cdad4057c79e Mon Sep 17 00:00:00 2001
From: Sam Bostock <sam.bostock@shopify.com>
Date: Tue, 30 Nov 2021 23:00:14 -0500
Subject: [PATCH 2/2] Make id field addition dangerous

---
 lib/graphql/schema_comparator/changes.rb                    | 6 +++++-
 .../graphql/schema_comparator/changes/field_added_test.rb   | 5 +++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/graphql/schema_comparator/changes.rb b/lib/graphql/schema_comparator/changes.rb
index 5e566f5..282d7a2 100644
--- a/lib/graphql/schema_comparator/changes.rb
+++ b/lib/graphql/schema_comparator/changes.rb
@@ -843,7 +843,11 @@ class FieldAdded < AbstractChange
         attr_reader :object_type, :field, :criticality
 
         def initialize(object_type, field)
-          @criticality = Changes::Criticality.non_breaking
+          @criticality = if field.graphql_name == 'id'
+                           Changes::Criticality.dangerous('this can blow up linters and change caching behaviour')
+                         else
+                           Changes::Criticality.non_breaking
+                         end
           @object_type = object_type
           @field = field
         end
diff --git a/test/lib/graphql/schema_comparator/changes/field_added_test.rb b/test/lib/graphql/schema_comparator/changes/field_added_test.rb
index e13d842..82b4dd6 100644
--- a/test/lib/graphql/schema_comparator/changes/field_added_test.rb
+++ b/test/lib/graphql/schema_comparator/changes/field_added_test.rb
@@ -10,12 +10,13 @@ def test_criticality_is_non_breaking_by_default
     assert change.non_breaking?
   end
 
-  def test_criticality_is_non_breaking_for_id_field_addition
+  def test_criticality_is_dangerous_for_id_field_addition
     change = GraphQL::SchemaComparator::Changes::FieldAdded.new(
       GraphQL::ObjectType.define { name "Type" },
       GraphQL::Field.define { name "id" },
     )
 
-    assert change.non_breaking?
+    assert change.dangerous?
+    assert_equal 'this can blow up linters and change caching behaviour', change.message
   end
 end