Use comment on view to generate TileJson (#1507)

Try to fix #1494 
- [x] Update
[query_available_tables.sql](https://github.com/maplibre/martin/pull/1507/files#diff-449496b294ee2413fc0d5e4290688a50f008e07fece5a613da1c2417548a06bf)
- [x] Add and update test

martin/src/pg/scripts/query_available_tables.sql

@@ -55,9 +55,10 @@ WITH
         SELECT
             pg_namespace.nspname AS schema_name,
             relname AS table_name,
-            CAST(obj_description(relfilenode, 'pg_class') AS VARCHAR) AS description
+            pg_description.description AS description
         FROM pg_class
             JOIN pg_namespace ON pg_class.relnamespace = pg_namespace.oid
+            LEFT JOIN pg_description ON pg_class.oid = pg_description.objoid
         WHERE relkind = 'r' OR relkind = 'v'
     )
 SELECT schema,

martin/tests/pg_server_test.rs

@@ -52,7 +52,7 @@ postgres:
     let response = assert_response(response).await;
     let body = read_body(response).await;
     let body: serde_json::Value = serde_json::from_slice(&body).unwrap();
-    assert_yaml_snapshot!(body, @r###"
+    assert_yaml_snapshot!(body, @r#"
     ---
     fonts: {}
     sprites: {}
@@ -111,8 +111,9 @@ postgres:
         content_type: application/x-protobuf
         description: public.points1.geom
       points1_vw:
+        attribution: some attribution from SQL comment
         content_type: application/x-protobuf
-        description: public.points1_vw.geom
+        description: description from SQL comment
       points2:
         content_type: application/x-protobuf
         description: public.points2.geom
@@ -127,7 +128,7 @@ postgres:
       table_source_multiple_geom.1:
         content_type: application/x-protobuf
         description: public.table_source_multiple_geom.geom2
-    "###);
+    "#);
 }
 
 #[actix_rt::test]

martin/tests/pg_table_source_test.rs

@@ -15,7 +15,7 @@ fn init() {
 #[actix_rt::test]
 async fn table_source() {
     let mock = mock_sources(mock_pgcfg("connection_string: $DATABASE_URL")).await;
-    assert_yaml_snapshot!(mock.0.tiles.get_catalog(), @r###"
+    assert_yaml_snapshot!(mock.0.tiles.get_catalog(), @r#"
     ---
     "-function.withweired---_-characters":
       content_type: application/x-protobuf
@@ -72,7 +72,8 @@ async fn table_source() {
       description: public.points1.geom
     points1_vw:
       content_type: application/x-protobuf
-      description: public.points1_vw.geom
+      description: description from SQL comment
+      attribution: some attribution from SQL comment
     points2:
       content_type: application/x-protobuf
       description: public.points2.geom
@@ -87,7 +88,7 @@ async fn table_source() {
     table_source_multiple_geom.1:
       content_type: application/x-protobuf
       description: public.table_source_multiple_geom.geom2
-    "###);
+    "#);
 
     let source = table(&mock, "table_source");
     assert_yaml_snapshot!(source, @r###"

tests/expected/auto/catalog_auto.json

@@ -106,7 +106,8 @@
     },
     "points1_vw": {
       "content_type": "application/x-protobuf",
-      "description": "public.points1_vw.geom"
+      "description": "description from SQL comment",
+      "attribution": "some attribution from SQL comment"
     },
     "points2": {
       "content_type": "application/x-protobuf",

tests/fixtures/tables/points1.sql

@@ -53,3 +53,12 @@ values (1, '0101000020E6100000EC3A2806EDDA61401C2041E87DDA2740'),
 
 CREATE INDEX ON points1 USING GIST (geom);
 CLUSTER points1_geom_idx ON points1;
+
+DO $do$ BEGIN
+    EXECUTE 'COMMENT ON VIEW points1_vw IS $tj$' || $$
+    {
+        "description": "description from SQL comment",
+        "attribution": "some attribution from SQL comment"
+    }
+    $$::json || '$tj$';
+END $do$;