unit tests + "last bend" bugfix

IV/tests.sql

@@ -1,10 +1,23 @@
+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)'));
 
-drop table if exists bends;
+do $$
-create table bends as (select * from detect_bends((select way from figures where name='fig3')));
+begin
-
+  perform assert_equals(3::bigint, (select count(1) from detect_bends((select way from figures where name='fig3'))));
---insert into figures (name, way) values ('Žeimena', (select st_linemerge(st_union(p.way)) from planet_osm_line p where p.name = 'Žeimena'))
+  perform assert_equals(3::bigint, (select count(1) from detect_bends((select way from figures where name='fig3-1'))));
+end $$ language plpgsql;

IV/wm.sql

@@ -36,5 +36,12 @@ begin
     end if;
     prev_sign = cur_sign;
   end loop;
+
+  -- the last bend may be lost if there is no "final" inflection angle.
+  -- to avoid that, return the last bend if the last accumulation has >3
+  -- vertices.
+  if (select count(1) from ((select st_dumppoints(bend) as a)) b) >= 3 then
+    return next;
+  end if;
 end
 $$ language plpgsql;