Fixes #2123

NEXT_CHANGELOG.md

@@ -186,7 +186,7 @@ From the CLI users can run:
 
 There are situations where comments and whitespace are not preserved. This may be improved in future.
 
-By [@bryncooke](https://github.com/bryncooke) in https://github.com/apollographql/router/pull/2116
+By [@bryncooke](https://github.com/bryncooke) in https://github.com/apollographql/router/pull/2116, https://github.com/apollographql/router/pull/2162
 
 ### *Experimental* subgraph request retry ([Issue #338](https://github.com/apollographql/router/issues/338), [Issue #1956](https://github.com/apollographql/router/issues/1956))
 

apollo-router/src/configuration/snapshots/apollo_router__configuration__upgrade__test__move_non_existent_field.snap

@@ -0,0 +1,7 @@
+---
+source: apollo-router/src/configuration/upgrade.rs
+expression: "apply_migration(&json!({ \"should\" : \"stay\" }),\n        &Migration::builder().action(Action::Move {\n                            from: \"obj.field1\".to_string(),\n                            to: \"new.obj.field1\".to_string(),\n                        }).description(\"move field1\").build()).expect(\"expected successful migration\")"
+---
+{
+  "should": "stay"
+}

apollo-router/src/configuration/upgrade.rs

@@ -70,22 +70,37 @@ fn apply_migration(config: &Value, migration: &Migration) -> Result<Value, Confi
     for action in &migration.actions {
         match action {
             Action::Delete { path } => {
-                // Deleting isn't actually supported by protus so we add a magic value to delete later
-                transformer_builder = transformer_builder.add_action(
-                    Parser::parse(REMOVAL_EXPRESSION, path).expect("migration must be valid"),
-                );
+                if !jsonpath_lib::select(config, &format!("$.{}", path))
+                    .unwrap_or_default()
+                    .is_empty()
+                {
+                    // Deleting isn't actually supported by protus so we add a magic value to delete later
+                    transformer_builder = transformer_builder.add_action(
+                        Parser::parse(REMOVAL_EXPRESSION, path).expect("migration must be valid"),
+                    );
+                }
             }
             Action::Copy { from, to } => {
-                transformer_builder = transformer_builder
-                    .add_action(Parser::parse(from, to).expect("migration must be valid"));
+                if !jsonpath_lib::select(config, &format!("$.{}", from))
+                    .unwrap_or_default()
+                    .is_empty()
+                {
+                    transformer_builder = transformer_builder
+                        .add_action(Parser::parse(from, to).expect("migration must be valid"));
+                }
             }
             Action::Move { from, to } => {
-                transformer_builder = transformer_builder
-                    .add_action(Parser::parse(from, to).expect("migration must be valid"));
-                // Deleting isn't actually supported by protus so we add a magic value to delete later
-                transformer_builder = transformer_builder.add_action(
-                    Parser::parse(REMOVAL_EXPRESSION, from).expect("migration must be valid"),
-                );
+                if !jsonpath_lib::select(config, &format!("$.{}", from))
+                    .unwrap_or_default()
+                    .is_empty()
+                {
+                    transformer_builder = transformer_builder
+                        .add_action(Parser::parse(from, to).expect("migration must be valid"));
+                    // Deleting isn't actually supported by protus so we add a magic value to delete later
+                    transformer_builder = transformer_builder.add_action(
+                        Parser::parse(REMOVAL_EXPRESSION, from).expect("migration must be valid"),
+                    );
+                }
             }
         }
     }
@@ -258,6 +273,21 @@ mod test {
         .expect("expected successful migration"));
     }
 
+    #[test]
+    fn move_non_existent_field() {
+        insta::assert_json_snapshot!(apply_migration(
+            &json!({"should": "stay"}),
+            &Migration::builder()
+                .action(Action::Move {
+                    from: "obj.field1".to_string(),
+                    to: "new.obj.field1".to_string()
+                })
+                .description("move field1")
+                .build(),
+        )
+        .expect("expected successful migration"));
+    }
+
     #[test]
     fn move_array_element() {
         insta::assert_json_snapshot!(apply_migration(