throw an exception when invalid geom passed to Sieve

.travis.yml

@@ -1,10 +1,16 @@
 language: node_js
+dist: bionic
 node_js:
-  - "0.10"
+  - 10
 sudo: false
+services:
+  - postgresql
 addons:
-  postgresql: 9.3
-before_install:
+  postgresql: 10
+  apt:
+    packages:
+    - postgresql-10-postgis-2.4
+before_script:
 - psql -U postgres -c "create database testing_postgis_vt_util"
 - psql -U postgres -d testing_postgis_vt_util -c "create extension postgis"
 script:

README.md

@@ -227,7 +227,7 @@ Filters small rings (both inner and outer) from a multipolygon based on area.
 __Parameters:__
 
 - `geometry` g - A multipolygon
-- `float` area_threshold - the minimum ring area to keep.
+- `anyelement` area_threshold - the minimum ring area to keep. Type must be either `float` or `integer`.
 
 __Returns:__ `geometry` - a polygon or multipolygon
 

postgis-vt-util.sql

@@ -428,51 +428,52 @@ Filters small rings (both inner and outer) from a multipolygon based on area.
 __Parameters:__
 
 - `geometry` g - A multipolygon
-- `float` area_threshold - the minimum ring area to keep.
+- `anyelement` area_threshold - the minimum ring area to keep. Type must be either `float` or `integer`.
 
 __Returns:__ `geometry` - a polygon or multipolygon
 ******************************************************************************/
-create or replace function Sieve (g geometry, area_threshold float)
+create or replace function Sieve (g geometry, area_threshold anyelement)
     returns geometry
-    language sql immutable as
-$func$
-    with exploded as (
-        -- First use ST_Dump to explode the input multipolygon
-        -- to individual polygons.
-        select (ST_Dump(g)).geom
-    ), rings as (
-        -- Next use ST_DumpRings to turn all of the inner and outer rings
-        -- into their own separate polygons.
-        select (ST_DumpRings(geom)).geom from exploded
-    ) select
-        -- Finally, build the multipolygon back up using only the rings
-        -- that are larger than the specified threshold area.
-            ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
-        from rings
-        where ST_Area(geom) > area_threshold;
-$func$;
-
-create or replace function Sieve (g geometry, area_threshold integer)
-    returns geometry
-    language sql immutable as
+    language plpgsql immutable as
 $func$
-    with exploded as (
-        -- First use ST_Dump to explode the input multipolygon
-        -- to individual polygons.
-        select (ST_Dump(g)).geom
-    ), rings as (
-        -- Next use ST_DumpRings to turn all of the inner and outer rings
-        -- into their own separate polygons.
-        select (ST_DumpRings(geom)).geom from exploded
-    ) select
-        -- Finally, build the multipolygon back up using only the rings
-        -- that are larger than the specified threshold area.
-            ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
-        from rings
-        where ST_Area(geom) > area_threshold;
-$func$;
+begin
 
+  -- DRY up code by defining one function for both integer and float inputs
+  -- define an empty polygon for the error detail to maintain geometry return type for any
+  -- functions that wrap this and expect a geometry to come back when we raise an exception
+  if pg_typeof(area_threshold) != all(array['integer', 'float']::regtype[]) then
+    raise exception using
+      errcode='INVAL',
+      message='Invalid parameter input in sieve- area_threshold must be either integer or float.',
+      detail=ST_GeomFromText('POLYGON EMPTY', ST_SRID(g));
+  end if;
+
+  if not st_isvalid(g) then
+    raise exception using
+      errcode='INVAL',
+      message='Invalid input geometry in sieve- will return null. See exception detail for location.',
+      detail=ST_SetSRID(location(ST_IsValidDetail(g)), ST_SRID(g));
+  end if;
+
+  return (
+  with exploded as (
+      -- First use ST_Dump to explode the input multipolygon
+      -- to individual polygons.
+      select (ST_Dump(g)).geom
+  ), rings as (
+      -- Next use ST_DumpRings to turn all of the inner and outer rings
+      -- into their own separate polygons.
+      select (ST_DumpRings(geom)).geom from exploded
+  ) select
+      -- Finally, build the multipolygon back up using only the rings
+      -- that are larger than the specified threshold area.
+          ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
+      from rings
+      where ST_Area(geom) > area_threshold
+  );
 
+end;
+$func$;
 /******************************************************************************
 ### SmartShrink ###
 

src/Sieve.sql

@@ -6,48 +6,49 @@ Filters small rings (both inner and outer) from a multipolygon based on area.
 __Parameters:__
 
 - `geometry` g - A multipolygon
-- `float` area_threshold - the minimum ring area to keep.
+- `anyelement` area_threshold - the minimum ring area to keep. Type must be either `float` or `integer`.
 
 __Returns:__ `geometry` - a polygon or multipolygon
 ******************************************************************************/
-create or replace function Sieve (g geometry, area_threshold float)
+create or replace function Sieve (g geometry, area_threshold anyelement)
     returns geometry
-    language sql immutable as
+    language plpgsql immutable as
 $func$
-    with exploded as (
-        -- First use ST_Dump to explode the input multipolygon
-        -- to individual polygons.
-        select (ST_Dump(g)).geom
-    ), rings as (
-        -- Next use ST_DumpRings to turn all of the inner and outer rings
-        -- into their own separate polygons.
-        select (ST_DumpRings(geom)).geom from exploded
-    ) select
-        -- Finally, build the multipolygon back up using only the rings
-        -- that are larger than the specified threshold area.
-            ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
-        from rings
-        where ST_Area(geom) > area_threshold;
-$func$;
+begin
 
-create or replace function Sieve (g geometry, area_threshold integer)
-    returns geometry
-    language sql immutable as
-$func$
-    with exploded as (
-        -- First use ST_Dump to explode the input multipolygon
-        -- to individual polygons.
-        select (ST_Dump(g)).geom
-    ), rings as (
-        -- Next use ST_DumpRings to turn all of the inner and outer rings
-        -- into their own separate polygons.
-        select (ST_DumpRings(geom)).geom from exploded
-    ) select
-        -- Finally, build the multipolygon back up using only the rings
-        -- that are larger than the specified threshold area.
-            ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
-        from rings
-        where ST_Area(geom) > area_threshold;
-$func$;
+  -- DRY up code by defining one function for both integer and float inputs
+  -- define an empty polygon for the error detail to maintain geometry return type for any
+  -- functions that wrap this and expect a geometry to come back when we raise an exception
+  if pg_typeof(area_threshold) != all(array['integer', 'float']::regtype[]) then
+    raise exception using
+      errcode='INVAL',
+      message='Invalid parameter input in sieve- area_threshold must be either integer or float.',
+      detail=ST_GeomFromText('POLYGON EMPTY', ST_SRID(g));
+  end if;
+
+  if not st_isvalid(g) then
+    raise exception using
+      errcode='INVAL',
+      message='Invalid input geometry in sieve- will return null. See exception detail for location.',
+      detail=ST_SetSRID(location(ST_IsValidDetail(g)), ST_SRID(g));
+  end if;
 
+  return (
+  with exploded as (
+      -- First use ST_Dump to explode the input multipolygon
+      -- to individual polygons.
+      select (ST_Dump(g)).geom
+  ), rings as (
+      -- Next use ST_DumpRings to turn all of the inner and outer rings
+      -- into their own separate polygons.
+      select (ST_DumpRings(geom)).geom from exploded
+  ) select
+      -- Finally, build the multipolygon back up using only the rings
+      -- that are larger than the specified threshold area.
+          ST_SetSRID(ST_BuildArea(ST_Collect(geom)), ST_SRID(g))
+      from rings
+      where ST_Area(geom) > area_threshold
+  );
 
+end;
+$func$;

test/sql-test.sh

@@ -133,7 +133,7 @@ tf ToPoint "ST_GeomFromText('MULTIPOLYGON(((0 0, 10 0, 10 10, 0 10, 0 0)))',9009
 tf ToPoint "ST_GeomFromText('MULTIPOLYGON(((0 0, 10 0, 10 10, 0 10, 0 0)), ((20 20, 30 20, 30 30, 20 30, 20 20)))',900913)" \
     "010100002031BF0D0000000000000014400000000000001440"
 tf ST_AsText "ToPoint(ST_GeomFromText('POLYGON((50 5,10 8,10 10,100 190,150 30,150 10,50 5))',900913))" \
-    "POINT(91.328125 97.5)"
+    "POINT(92.5 110)"
 
 
 # Z