create schema if not exists test; \i wm.sql -- https://stackoverflow.com/questions/19982373/which-tools-libraries-do-you-use-to-unit-test-your-pl-pgsql CREATE OR REPLACE FUNCTION assert_equals(expected anyelement, actual anyelement) RETURNS void AS $$ begin if expected = actual or (expected is null and actual is null) then --do nothing else raise exception 'Assertion Error. Expected <%> but was <%>', expected, actual; end if; end $$ LANGUAGE plpgsql; drop table if exists figures; create table figures (name text, way geometry); insert into figures (name, way) values ('fig3',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0,60 0)')); insert into figures (name, way) values ('fig3-1',ST_GeomFromText('LINESTRING(0 0,12 0,13 4,20 2,20 0,32 0,33 10,38 16,43 15,44 10,44 0)')); insert into figures (name, way) values ('fig5',ST_GeomFromText('LINESTRING(0 39,19 52,27 77,26 104,41 115,49 115,65 103,65 75,53 45,63 15,91 0,91 0)')); drop table if exists bends; create table bends (way geometry); insert into bends select unnest(detect_bends((select way from figures where name='fig3'))); insert into bends select unnest(detect_bends((select way from figures where name='fig5'))); do $$ declare bends geometry[]; begin select detect_bends((select way from figures where name='fig3')) into bends; perform assert_equals(5, array_length(bends, 1)); perform assert_equals('LINESTRING(0 0,12 0,13 4)', st_astext(bends[1])); perform assert_equals('LINESTRING(12 0,13 4,20 2,20 0)', st_astext(bends[2])); perform assert_equals('LINESTRING(20 2,20 0,32 0,33 10)', st_astext(bends[3])); perform assert_equals('LINESTRING(32 0,33 10,38 16,43 15,44 10,44 0)', st_astext(bends[4])); perform assert_equals(4, array_length(detect_bends((select way from figures where name='fig3-1')), 1)); select detect_bends((select way from figures where name='fig5')) into bends; perform assert_equals(3, array_length(bends, 1)); end $$ language plpgsql;