From 416fb7abd72f8608b84644fb9efd71eaa86f8a46 Mon Sep 17 00:00:00 2001
From: Andrew Farries <andyrb@gmail.com>
Date: Fri, 8 Nov 2024 14:31:14 +0000
Subject: [PATCH] Update schema during add column validation (#457)

Update the schema during `add_column` operation validation so that
validation of subsequent operations in the same migration can see the
new column.

This means that migrations that add a new column and then perform some
other operation, like adding an index, on that column can be validated
because the new column is visible to the `create_index` operation during
it's validation phase.

This means that the following migration is now able to validate:

```json
{
  "name": "43_multiple_ops",
  "operations": [
    {
      "add_column": {
        "table": "players",
        "column": {
          "name": "rating",
          "type": "integer",
          "comment": "hello world",
          "check": {
            "name": "rating_check",
            "constraint": "rating > 0 AND rating < 100"
          },
          "nullable": false
        }
      }
    },
    {
      "create_index": {
        "name": "idx_player_rating",
        "table": "players",
        "columns": [
          "rating"
        ]
      }
    }
  ]
}
```

Previously, the new column would not have been visible to the
`create_index` operation and its validation would have failed.

This PR does for the `add_column` operation what #455 did for the
`create_table` operation.

Part of https://github.com/xataio/pgroll/issues/239
---
 pkg/migrations/op_add_column.go        | 6 ++++++
 pkg/migrations/op_create_index_test.go | 3 +--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/pkg/migrations/op_add_column.go b/pkg/migrations/op_add_column.go
index 43022662..b6595683 100644
--- a/pkg/migrations/op_add_column.go
+++ b/pkg/migrations/op_add_column.go
@@ -184,6 +184,12 @@ func (o *OpAddColumn) Validate(ctx context.Context, s *schema.Schema) error {
 		return errors.New("adding primary key columns is not supported")
 	}
 
+	// Update the schema to ensure that the new column is visible to validation of
+	// subsequent operations.
+	table.AddColumn(o.Column.Name, schema.Column{
+		Name: TemporaryName(o.Column.Name),
+	})
+
 	return nil
 }
 
diff --git a/pkg/migrations/op_create_index_test.go b/pkg/migrations/op_create_index_test.go
index 3b9cdc64..62eaeb5f 100644
--- a/pkg/migrations/op_create_index_test.go
+++ b/pkg/migrations/op_create_index_test.go
@@ -9,7 +9,6 @@ import (
 	"testing"
 
 	"github.com/xataio/pgroll/pkg/migrations"
-	"github.com/xataio/pgroll/pkg/roll"
 )
 
 func TestCreateIndex(t *testing.T) {
@@ -417,5 +416,5 @@ func TestCreateIndexOnObjectsCreatedInSameMigration(t *testing.T) {
 				IndexMustExist(t, db, schema, "users", "idx_users_age")
 			},
 		},
-	}, roll.WithSkipValidation(true)) // TODO: Remove once these migrations pass validation
+	})
 }