From 12b4195f888913ac6a902dcbeeda53c23fe71926 Mon Sep 17 00:00:00 2001
From: Dan Lynch <pyramation@gmail.com>
Date: Wed, 11 Feb 2026 09:16:49 +0000
Subject: [PATCH] fix(graphile-settings): add standalone UppercaseEnumsPlugin
 for v4 CONSTANT_CASE enum values

---
 .../graphile-settings/src/plugins/index.ts    |  6 ++++
 .../src/plugins/uppercase-enums.ts            | 33 +++++++++++++++++++
 .../src/presets/constructive-preset.ts        |  2 ++
 3 files changed, 41 insertions(+)
 create mode 100644 graphile/graphile-settings/src/plugins/uppercase-enums.ts

diff --git a/graphile/graphile-settings/src/plugins/index.ts b/graphile/graphile-settings/src/plugins/index.ts
index 3d26bee71..a7f4da51a 100644
--- a/graphile/graphile-settings/src/plugins/index.ts
+++ b/graphile/graphile-settings/src/plugins/index.ts
@@ -63,6 +63,12 @@ export {
 } from './pg-type-mappings';
 export type { TypeMapping } from './pg-type-mappings';
 
+// Uppercase enum values to match v4 CONSTANT_CASE convention
+export {
+  UppercaseEnumsPlugin,
+  UppercaseEnumsPreset,
+} from './uppercase-enums';
+
 // Search plugin for tsvector full-text search conditions (includes TsvectorCodec)
 export {
   PgSearchPlugin,
diff --git a/graphile/graphile-settings/src/plugins/uppercase-enums.ts b/graphile/graphile-settings/src/plugins/uppercase-enums.ts
new file mode 100644
index 000000000..86da0cc8e
--- /dev/null
+++ b/graphile/graphile-settings/src/plugins/uppercase-enums.ts
@@ -0,0 +1,33 @@
+import type { GraphileConfig } from 'graphile-config';
+
+/**
+ * Plugin that uppercases PostgreSQL enum values in the GraphQL schema.
+ *
+ * WHY THIS EXISTS:
+ * In PostGraphile v4, custom PostgreSQL enum values (e.g., 'app', 'core', 'module')
+ * were automatically uppercased to CONSTANT_CASE ('APP', 'CORE', 'MODULE').
+ * In PostGraphile v5, the default `enumValue` inflector preserves the original
+ * PostgreSQL casing via `coerceToGraphQLName(value)`, resulting in lowercase
+ * enum values in the GraphQL schema.
+ *
+ * This plugin overrides the `enumValue` inflector to uppercase the result,
+ * restoring v4 behavior. It delegates to the previous inflector first to
+ * retain all special character handling (asterisks, symbols, etc.).
+ */
+export const UppercaseEnumsPlugin: GraphileConfig.Plugin = {
+  name: 'UppercaseEnumsPlugin',
+  version: '1.0.0',
+
+  inflection: {
+    replace: {
+      enumValue(previous, _options, value, codec) {
+        const result = previous!(value, codec);
+        return result.toUpperCase();
+      },
+    },
+  },
+};
+
+export const UppercaseEnumsPreset: GraphileConfig.Preset = {
+  plugins: [UppercaseEnumsPlugin],
+};
diff --git a/graphile/graphile-settings/src/presets/constructive-preset.ts b/graphile/graphile-settings/src/presets/constructive-preset.ts
index 5c8c42ce4..020293fcc 100644
--- a/graphile/graphile-settings/src/presets/constructive-preset.ts
+++ b/graphile/graphile-settings/src/presets/constructive-preset.ts
@@ -10,6 +10,7 @@ import { ManyToManyOptInPreset } from '../plugins/many-to-many-preset';
 import { MetaSchemaPreset } from '../plugins/meta-schema';
 import { PgSearchPreset } from 'graphile-search-plugin';
 import { PgTypeMappingsPreset } from '../plugins/pg-type-mappings';
+import { UppercaseEnumsPreset } from '../plugins/uppercase-enums';
 
 /**
  * Constructive PostGraphile v5 Preset
@@ -61,6 +62,7 @@ export const ConstructivePreset: GraphileConfig.Preset = {
     MetaSchemaPreset,
     PgSearchPreset({ pgSearchPrefix: 'fullText' }),
     PgTypeMappingsPreset,
+    UppercaseEnumsPreset,
   ],
   /**
    * Disable relation filter plugins from postgraphile-plugin-connection-filter.