feat(cubesql): Add CURRENT_DATE function definitions for Postgres and Snowflake so those can be pushed down

Author: paveltiunov

packages/cubejs-schema-compiler/src/adapter/PostgresQuery.ts

@@ -50,6 +50,8 @@ export class PostgresQuery extends BaseQuery {
     templates.functions.DATETRUNC = 'DATE_TRUNC({{ args_concat }})';
     templates.functions.CONCAT = 'CONCAT({% for arg in args %}CAST({{arg}} AS TEXT){% if not loop.last %},{% endif %}{% endfor %})';
     templates.functions.DATEPART = 'DATE_PART({{ args_concat }})';
+    templates.functions.CURRENTDATE = 'CURRENT_DATE';
+    templates.functions.NOW = 'NOW({{ args_concat }})';
     // DATEADD is being rewritten to DATE_ADD
     // templates.functions.DATEADD = '({{ args[2] }} + \'{{ interval }} {{ date_part }}\'::interval)';
     delete templates.functions.DATEDIFF;

packages/cubejs-schema-compiler/src/adapter/SnowflakeQuery.ts

@@ -54,6 +54,8 @@ export class SnowflakeQuery extends BaseQuery {
     const templates = super.sqlTemplates();
     templates.functions.DATETRUNC = 'DATE_TRUNC({{ args_concat }})';
     templates.functions.DATEPART = 'DATE_PART({{ args_concat }})';
+    templates.functions.CURRENTDATE = 'CURRENT_DATE';
+    templates.functions.NOW = 'CURRENT_TIMESTAMP';
     templates.functions.LOG = 'LOG({% if args[1] is undefined %}10, {% endif %}{{ args_concat }})';
     templates.functions.DLOG10 = 'LOG(10, {{ args_concat }})';
     templates.functions.CHARACTERLENGTH = 'LENGTH({{ args[0] }})';