feat: Support accessing array items and fields of composite types through json operators

This is supported in select=, in filters and in order=.

Resolves #1543

Resolves #2075

Signed-off-by: Wolfgang Walther <walther@technowledgy.de>

test/spec/fixtures/data.sql

@@ -730,3 +730,9 @@ INSERT INTO test.clientinfo (id,clientid, other) values (1,1,'123 Main St'),(2,2
 
 TRUNCATE TABLE test.chores CASCADE;
 INSERT INTO test.chores (id, name, done) values (1, 'take out the garbage', true), (2, 'do the laundry', false), (3, 'wash the dishes', null);
+
+TRUNCATE TABLE test.fav_numbers CASCADE;
+INSERT INTO test.fav_numbers VALUES (ROW(0.5, 0.5), 'A'),  (ROW(0.6, 0.6), 'B');
+
+TRUNCATE TABLE test.arrays CASCADE;
+INSERT INTO test.arrays VALUES (0, '{1,2,3}', '{{1,2,3},{4,5,6},{7,8,9}}'), (1, '{11,12,13}', '{{11,12,13},{14,15,16},{17,18,19}}');

test/spec/fixtures/privileges.sql

@@ -19,6 +19,7 @@ GRANT ALL ON TABLE
     , items3
     , "articleStars"
     , articles
+    , arrays
     , auto_incrementing_pk
     , clients
     , comments
@@ -27,6 +28,7 @@ GRANT ALL ON TABLE
     , compound_pk_view
     , deferrable_unique_constraint
     , empty_table
+    , fav_numbers
     , has_count_column
     , has_fk
     , insertable_view_with_join

test/spec/fixtures/schema.sql

@@ -2427,3 +2427,21 @@ BEGIN
   END IF;
 END
 $do$;
+
+-- https://github.com/PostgREST/postgrest/issues/1543
+CREATE TYPE complex AS (
+ r double precision,
+ i double precision
+);
+
+CREATE TABLE test.fav_numbers (
+ num    complex,
+ person text
+);
+
+-- https://github.com/PostgREST/postgrest/issues/2075
+create table test.arrays (
+  id int primary key,
+  numbers int[],
+  numbers_mult int[][]
+);