feat: inline pg-type-mappings plugin into graphile-settings

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/attachment.sql

@@ -2,6 +2,6 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN attachment AS text CHECK (VALUE ~ '^(https?)://[^\s/$.?#].[^\s]*$');
-COMMENT ON DOMAIN attachment IS E'@name pgpmInternalTypeAttachment';
+CREATE DOMAIN attachment AS text;
+COMMENT ON DOMAIN attachment IS E'@name constructiveInternalTypeAttachment';
 COMMIT;

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/email.sql

@@ -2,7 +2,7 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN email AS citext CHECK (value ~ '^[a-zA-Z0-9.!#$%&''*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$');
-COMMENT ON DOMAIN email IS E'@name pgpmInternalTypeEmail';
+CREATE DOMAIN email AS citext;
+COMMENT ON DOMAIN email IS E'@name constructiveInternalTypeEmail';
 COMMIT;
 

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/hostname.sql

@@ -2,7 +2,7 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN hostname AS text CHECK (VALUE ~ '^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$');
-COMMENT ON DOMAIN hostname IS E'@name pgpmInternalTypeHostname';
+CREATE DOMAIN hostname AS text;
+COMMENT ON DOMAIN hostname IS E'@name constructiveInternalTypeHostname';
 COMMIT;
 

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/image.sql

@@ -2,11 +2,7 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN image AS jsonb CHECK (
-  value ?& ARRAY['url', 'mime']
-  AND
-  value->>'url' ~ '^(https?)://[^\s/$.?#].[^\s]*$'
-);
-COMMENT ON DOMAIN image IS E'@name pgpmInternalTypeImage';
+CREATE DOMAIN image AS jsonb CHECK (value ? 'url');
+COMMENT ON DOMAIN image IS E'@name constructiveInternalTypeImage';
 COMMIT;
 

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/origin.sql

@@ -2,7 +2,7 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN origin AS text CHECK (VALUE = substring(VALUE from '^(https?://[^/]*)'));
-COMMENT ON DOMAIN origin IS E'@name pgpmInternalTypeOrigin';
+CREATE DOMAIN origin AS text CHECK (value ~ '^https?://[^\s]+$');
+COMMENT ON DOMAIN origin IS E'@name constructiveInternalTypeOrigin';
 COMMIT;
 

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/upload.sql

@@ -1,14 +1,7 @@
 -- Deploy schemas/public/domains/upload to pg
-
 -- requires: schemas/public/schema
 
 BEGIN;
-
-CREATE DOMAIN upload AS jsonb CHECK (
-  value ?& ARRAY['url', 'mime']
-  AND
-  value->>'url' ~ '^(https?)://[^\s/$.?#].[^\s]*$'
-);
-COMMENT ON DOMAIN upload IS E'@name pgpmInternalTypeUpload';
-
+CREATE DOMAIN upload AS jsonb CHECK (value ? 'url' OR value ? 'id' OR value ? 'key');
+COMMENT ON DOMAIN upload IS E'@name constructiveInternalTypeUpload';
 COMMIT;

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/deploy/schemas/public/domains/url.sql

@@ -2,7 +2,7 @@
 -- requires: schemas/public/schema
 
 BEGIN;
-CREATE DOMAIN url AS text CHECK (VALUE ~ '^(https?)://[^\s/$.?#].[^\s]*$');
-COMMENT ON DOMAIN url IS E'@name pgpmInternalTypeUrl';
+CREATE DOMAIN url AS text CHECK (value ~ '^https?://[^\s]+$');
+COMMENT ON DOMAIN url IS E'@name constructiveInternalTypeUrl';
 COMMIT;
 

__fixtures__/sqitch/simple-w-exts/extensions/@pgpm/types/pgpm.plan

@@ -7,8 +7,6 @@ schemas/public/domains/attachment [schemas/public/schema] 2017-08-11T08:11:51Z s
 schemas/public/domains/email [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/email
 schemas/public/domains/hostname [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/hostname
 schemas/public/domains/image [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/image
-schemas/public/domains/multiple_select [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/multiple_select
 schemas/public/domains/origin [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/origin
-schemas/public/domains/single_select [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/single_select
 schemas/public/domains/upload [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/upload
 schemas/public/domains/url [schemas/public/schema] 2017-08-11T08:11:51Z skitch <skitch@5b0c196eeb62> # add schemas/public/domains/url

graphile/graphile-settings/src/plugins/index.ts

@@ -61,3 +61,10 @@ export {
   TsvectorCodecPlugin,
   TsvectorCodecPreset,
 } from './tsvector-codec';
+
+// PG type mappings for custom PostgreSQL types (email, url, etc.)
+export {
+  PgTypeMappingsPlugin,
+  PgTypeMappingsPreset,
+} from './pg-type-mappings';
+export type { TypeMapping } from './pg-type-mappings';

graphile/graphile-settings/src/plugins/pg-type-mappings.ts

@@ -0,0 +1,154 @@
+import type { GraphileConfig } from 'graphile-config';
+import { GraphQLString } from 'grafast/graphql';
+import sql from 'pg-sql2';
+
+/**
+ * Type mapping configuration for custom PostgreSQL types.
+ */
+export interface TypeMapping {
+  /** PostgreSQL type name */
+  name: string;
+  /** PostgreSQL schema/namespace name */
+  namespaceName: string;
+  /** GraphQL type to map to */
+  type: 'String';
+}
+
+/**
+ * Default type mappings for common custom PostgreSQL types.
+ * These are typically domain types or composite types that should be
+ * represented as simple scalars in GraphQL.
+ */
+const DEFAULT_MAPPINGS: TypeMapping[] = [
+  { name: 'email', namespaceName: 'public', type: 'String' },
+  { name: 'hostname', namespaceName: 'public', type: 'String' },
+  { name: 'origin', namespaceName: 'public', type: 'String' },
+  { name: 'url', namespaceName: 'public', type: 'String' },
+];
+
+/**
+ * Plugin that maps custom PostgreSQL types to GraphQL scalar types.
+ *
+ * This is useful for domain types or composite types that should be
+ * represented as simple scalars (String, JSON) in the GraphQL API.
+ *
+ * For example, if you have:
+ *   CREATE DOMAIN email AS text;
+ *   CREATE TYPE url AS (value text);
+ *
+ * This plugin will map them to GraphQL String type instead of creating
+ * complex object types.
+ *
+ * The plugin handles both:
+ * 1. Domain types (simple aliases) - maps directly to the target scalar
+ * 2. Composite types - extracts the first field's value when converting from PG
+ */
+export const PgTypeMappingsPlugin: GraphileConfig.Plugin = {
+  name: 'PgTypeMappingsPlugin',
+  version: '1.0.0',
+
+  gather: {
+    hooks: {
+      async pgCodecs_findPgCodec(info, event) {
+        if (event.pgCodec) {
+          return;
+        }
+
+        const { pgType: type, serviceName } = event;
+
+        // Find the namespace for this type
+        const namespace = await info.helpers.pgIntrospection.getNamespace(
+          serviceName,
+          type.typnamespace
+        );
+
+        if (!namespace) {
+          return;
+        }
+
+        // Check if this type matches any of our mappings
+        const mapping = DEFAULT_MAPPINGS.find(
+          m => m.name === type.typname && m.namespaceName === namespace.nspname
+        );
+
+        if (!mapping) {
+          return;
+        }
+
+        // Create a codec for this type
+        // For composite types, the fromPg function extracts the first field's value
+        // For domain types, it just passes through the value
+        event.pgCodec = {
+          name: type.typname,
+          sqlType: sql.identifier(namespace.nspname, type.typname),
+          fromPg: (value: unknown) => {
+            if (value == null) {
+              return null;
+            }
+            // If it's already a scalar, return it
+            if (typeof value !== 'object' || Array.isArray(value)) {
+              return value;
+            }
+            // For composite types, extract the first field's value
+            const obj = value as Record<string, unknown>;
+            const keys = Object.keys(obj);
+            if (keys.length > 0) {
+              return obj[keys[0]];
+            }
+            return value;
+          },
+          toPg: (value: unknown) => value as string,
+          attributes: undefined,
+          executor: null,
+          extensions: {
+            oid: type._id,
+            pg: {
+              serviceName,
+              schemaName: namespace.nspname,
+              name: type.typname,
+            },
+            tags: {
+              // Mark this as a custom mapped type
+              pgTypeMappings: mapping.type,
+            },
+          },
+        };
+      },
+    },
+  },
+
+  schema: {
+    hooks: {
+      init(_, build) {
+        const { setGraphQLTypeForPgCodec } = build;
+
+        // Map our custom codecs to GraphQL types
+        for (const codec of Object.values(build.input.pgRegistry.pgCodecs)) {
+          const mappingType = codec.extensions?.tags?.pgTypeMappings as string | undefined;
+          if (mappingType) {
+            const gqlTypeName = GraphQLString.name;
+            setGraphQLTypeForPgCodec(codec, 'input', gqlTypeName);
+            setGraphQLTypeForPgCodec(codec, 'output', gqlTypeName);
+          }
+        }
+
+        return _;
+      },
+    },
+  },
+};
+
+/**
+ * Preset that includes the PG type mappings plugin.
+ *
+ * This preset maps common custom PostgreSQL types to GraphQL scalars:
+ * - email -> String
+ * - hostname -> String
+ * - url -> String
+ * - origin -> String
+ */
+export const PgTypeMappingsPreset: GraphileConfig.Preset = {
+  plugins: [PgTypeMappingsPlugin],
+};
+
+export default PgTypeMappingsPlugin;

graphile/graphile-settings/src/presets/constructive-preset.ts

@@ -9,6 +9,7 @@ import { EnableAllFilterColumnsPreset } from '../plugins/enable-all-filter-colum
 import { ManyToManyOptInPreset } from '../plugins/many-to-many-preset';
 import { MetaSchemaPreset } from '../plugins/meta-schema';
 import { TsvectorCodecPreset } from '../plugins/tsvector-codec';
+import { PgTypeMappingsPreset } from '../plugins/pg-type-mappings';
 
 /**
  * Constructive PostGraphile v5 Preset
@@ -25,6 +26,7 @@ import { TsvectorCodecPreset } from '../plugins/tsvector-codec';
  * - Connection filter plugin with all columns filterable
  * - Many-to-many relationships (opt-in via @behavior +manyToMany)
  * - Meta schema plugin (_meta query for introspection of tables, fields, indexes)
+ * - PG type mappings (maps custom types like email, url to GraphQL scalars)
  *
  * DISABLED PLUGINS:
  * - PgConnectionArgFilterBackwardRelationsPlugin (relation filters bloat the API)
@@ -58,6 +60,7 @@ export const ConstructivePreset: GraphileConfig.Preset = {
     ManyToManyOptInPreset,
     MetaSchemaPreset,
     TsvectorCodecPreset,
+    PgTypeMappingsPreset,
   ],
   /**
    * Disable relation filter plugins from postgraphile-plugin-connection-filter.