should be it

external/duckdb/test/sql/window/test_empty_frames.test

@@ -0,0 +1,172 @@
+# name: test/sql/window/test_empty_frames.test
+# description: Empty aggregate frames
+# group: [window]
+
+statement ok
+PRAGMA enable_verification
+
+statement ok
+CREATE TABLE t1 (id INTEGER, ch CHAR(1)) ;
+
+statement ok
+INSERT INTO t1 VALUES (1, 'A');
+
+statement ok
+INSERT INTO t1 VALUES (2, 'B');
+
+statement ok
+INSERT INTO t1 VALUES (NULL, 'B');
+
+#
+# Original bug report
+#
+
+foreach agg count(*) count_star()
+
+query II
+SELECT id, ${agg} OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	0
+2	1
+NULL	0
+
+endloop
+
+#
+# All zeroes
+#
+foreach agg approx_count_distinct count entropy
+
+query II
+SELECT id, ${agg}(id) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	0
+2	 0
+NULL	0
+
+endloop
+
+#
+# All NULLs
+#
+foreach agg any_value arbitrary avg bit_and bit_or bit_xor favg first fsum group_concat histogram kahan_sum kurtosis last listagg mad max mean median min mode product sem skewness stddev stddev_pop stddev_samp sum sumkahan var_pop var_samp variance
+
+query II
+SELECT id, ${agg}(id) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+endloop
+
+#
+# Custom results
+#
+
+# Numeric parameter argument
+foreach agg approx_quantile quantile quantile_cont quantile_disc reservoir_quantile
+
+query II
+SELECT id, ${agg}(id, 0.5) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+endloop
+
+# Mixed arguments
+foreach agg arg_max arg_min argmax argmin max_by min_by
+
+query II
+SELECT id, ${agg}(id, ch) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+endloop
+
+foreach agg array_agg list
+
+query II
+SELECT id, ${agg}(id) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	[NULL]
+NULL	NULL
+
+endloop
+
+# Boolean argument
+foreach agg bool_and bool_or
+
+query II
+SELECT id, ${agg}(id > 0) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+endloop
+
+# Two numeric arguments =>NULL
+foreach agg corr covar_pop covar_samp regr_avgx regr_avgy regr_intercept regr_r2 regr_slope regr_sxx regr_sxy regr_syy
+
+query II
+SELECT id, ${agg}(id, id) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+endloop
+
+# Two numeric arguments => 0
+foreach agg regr_count
+
+query II
+SELECT id, ${agg}(id, id) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	0
+2	0
+NULL	0
+
+endloop
+
+query II
+SELECT id, string_agg(id, ' ') OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL
+
+query II
+SELECT id, bitstring_agg(id, 1, 3) OVER (PARTITION BY ch ORDER BY id ROWS BETWEEN 1 FOLLOWING AND 2 FOLLOWING) 
+FROM t1
+ORDER BY 1;
+----
+1	NULL
+2	NULL
+NULL	NULL