fix(graphile-postgis): detect PostGIS when only geography codecs are present

Previously, PostgisExtensionDetectionPlugin required a geometry codec to
detect PostGIS. Databases that use only geography columns (e.g. all
DataPostGIS nodes with use_geography: true) would not have a geometry
codec introspected, causing PostGIS detection to silently fail and
geography columns to be omitted from the GraphQL schema with warnings:

  Do not know how to convert PgCodec 'geography' into a GraphQL type

Changes:
- detect-extension.ts: Accept either geometry OR geography codec
- detect-extension.ts: Extract schemaName from geography codec when
  geometry is absent
- types.ts: Make geometryCodec nullable (PgCodec | null)
- connection-filter-operators.ts: Handle null geometryCodec in codec
  pairs
- within-distance-operator.ts: Handle null geometryCodec in codec pairs

Author: pyramation

graphile/graphile-postgis/src/plugins/connection-filter-operators.ts

@@ -1,5 +1,7 @@
 import 'graphile-build';
+import 'graphile-build-pg';
 import 'graphile-connection-filter';
+import type { PgCodec } from '@dataplan/pg';
 import type {
   ConnectionFilterOperatorFactory,
   ConnectionFilterOperatorRegistration,
@@ -225,7 +227,10 @@ export function createPostgisOperatorFactory(): ConnectionFilterOperatorFactory
       geography: []
     };
 
-    const codecPairs: [string, typeof geometryCodec][] = [['geometry', geometryCodec]];
+    const codecPairs: [string, PgCodec][] = [];
+    if (geometryCodec) {
+      codecPairs.push(['geometry', geometryCodec]);
+    }
     if (geographyCodec) {
       codecPairs.push(['geography', geographyCodec]);
     }

graphile/graphile-postgis/src/plugins/detect-extension.ts

@@ -43,13 +43,17 @@ export const PostgisExtensionDetectionPlugin: GraphileConfig.Plugin = {
             schemaName = pg.schemaName || 'public';
           } else if (pg.name === 'geography') {
             geographyCodec = codec;
+            if (!geometryCodec) {
+              schemaName = pg.schemaName || 'public';
+            }
           }
         }
 
-        // PostGIS requires at least the geometry codec to be present.
-        // Geography is optional — not all databases use geography columns,
-        // so PostGraphile may not introspect the geography type at all.
-        if (!geometryCodec) {
+        // PostGIS is detected when at least one of geometry or geography
+        // codecs is present. Some databases use only geography columns
+        // (e.g. use_geography: true in DataPostGIS), so PostGraphile may
+        // introspect geography but not geometry.
+        if (!geometryCodec && !geographyCodec) {
           return build;
         }
 

graphile/graphile-postgis/src/plugins/within-distance-operator.ts

@@ -1,5 +1,7 @@
 import 'graphile-build';
+import 'graphile-build-pg';
 import 'graphile-connection-filter';
+import type { PgCodec } from '@dataplan/pg';
 import type {
   ConnectionFilterOperatorFactory,
   ConnectionFilterOperatorRegistration,
@@ -57,7 +59,10 @@ export function createWithinDistanceOperatorFactory(): ConnectionFilterOperatorF
       geography: []
     };
 
-    const codecPairs: [string, typeof geometryCodec][] = [['geometry', geometryCodec]];
+    const codecPairs: [string, PgCodec][] = [];
+    if (geometryCodec) {
+      codecPairs.push(['geometry', geometryCodec]);
+    }
     if (geographyCodec) {
       codecPairs.push(['geography', geographyCodec]);
     }

graphile/graphile-postgis/src/types.ts

@@ -23,9 +23,9 @@ export interface GisFieldValue {
 export interface PostgisExtensionInfo {
   /** The schema name where PostGIS is installed (e.g. 'public') */
   schemaName: string;
-  /** The geometry codec from the registry */
-  geometryCodec: PgCodec;
-  /** The geography codec from the registry (optional — not all databases use geography columns) */
+  /** The geometry codec from the registry (null if only geography columns are used) */
+  geometryCodec: PgCodec | null;
+  /** The geography codec from the registry (null if only geometry columns are used) */
   geographyCodec: PgCodec | null;
 }