Fix test to work across all databases without json_extract

PostgreSQL doesn't have json_extract, so compare the full JSON string instead.

Author: lovasoa

…variables_nomssql_nopostgres_nomysql.sql …t_files/it_works_immutable_variables.sqltests/sql_test_files/it_works_immutable_variables_nomssql_nopostgres_nomysql.sql renamed to tests/sql_test_files/it_works_immutable_variables.sql tests/sql_test_files/it_works_immutable_variables_nomssql_nopostgres_nomysql.sql renamed to tests/sql_test_files/it_works_immutable_variables.sql

@@ -1,4 +1,3 @@
--- This test uses json_extract() which is SQLite-specific
 SET x = 'set_value';
 SET set_only = 'only_in_set';
 
@@ -16,19 +15,17 @@ SELECT CASE
 END AS contents;
 
 SELECT CASE
-    WHEN json_extract(sqlpage.variables('get'), '$.x') = '1' THEN 'It works !'
-    ELSE 'FAIL: variables(''get'') should return only URL parameters'
+    WHEN sqlpage.variables('get') = '{"x":"1"}' THEN 'It works !'
+    ELSE 'FAIL: variables(''get'') should return only URL parameters, got: ' || sqlpage.variables('get')
 END AS contents;
 
 SELECT CASE
-    WHEN json_extract(sqlpage.variables('set'), '$.x') = 'set_value' AND
-         json_extract(sqlpage.variables('set'), '$.set_only') = 'only_in_set' THEN 'It works !'
-    ELSE 'FAIL: variables(''set'') should return only SET variables'
+    WHEN sqlpage.variables('set') = '{"x":"set_value","set_only":"only_in_set"}' THEN 'It works !'
+    ELSE 'FAIL: variables(''set'') should return only SET variables, got: ' || sqlpage.variables('set')
 END AS contents;
 
 SELECT CASE
-    WHEN json_extract(sqlpage.variables(), '$.x') = 'set_value' AND
-         json_extract(sqlpage.variables(), '$.set_only') = 'only_in_set' THEN 'It works !'
-    ELSE 'FAIL: variables() should merge all with SET taking precedence'
+    WHEN sqlpage.variables() = '{"x":"set_value","set_only":"only_in_set"}' THEN 'It works !'
+    ELSE 'FAIL: variables() should merge all with SET taking precedence, got: ' || sqlpage.variables()
 END AS contents;