Add an "int16" property type (#1358)

* Add an "int16" property type

Resolves #1321

* Update reference in change log

* Code cleanup to improve readability

CHANGES.txt

@@ -8,6 +8,8 @@ All issue numbers are relative to https://github.com/Toblerity/Fiona/issues.
 
 Bug fixes:
 
+- Add a 16-bit integer type "int16" based on OGR's OSFTInt16 integer sub-type
+  (#1358).
 - Allow a GeoJSON collection's layer name to be set on opening in write mode
   (#1352).
 - The legacy crs.py module which was shadowed by the new crs.pyx module has

fiona/ogrext.pyx

@@ -778,6 +778,7 @@ cdef class Session:
                 continue
 
             fieldtypename = FIELD_TYPES[OGR_Fld_GetType(cogr_fielddefn)]
+            fieldsubtype = OGR_Fld_GetSubType(cogr_fielddefn)
 
             if not fieldtypename:
                 log.warning(
@@ -786,39 +787,44 @@ cdef class Session:
                     OGR_Fld_GetType(cogr_fielddefn))
                 continue
 
-            val = fieldtypename
-
-            if fieldtypename == 'float':
-                fmt = ""
+            if fieldtypename == "float":
                 width = OGR_Fld_GetWidth(cogr_fielddefn)
-
-                if width: # and width != 24:
-                    fmt = f":{width:d}"
-
                 precision = OGR_Fld_GetPrecision(cogr_fielddefn)
-
-                if precision: # and precision != 15:
+                fmt = ""
+                if width:
+                    fmt = f":{width:d}"
+                if precision:
                     fmt += f".{precision:d}"
+                val = f"float{fmt}"
 
-                val = "float" + fmt
+            elif fieldtypename == "int32":
+                if fieldsubtype == OFSTBoolean:
+                    val = "bool"
+                elif fieldsubtype == OFSTInt16:
+                    val = "int16"
+                else:
+                    fmt = ""
+                    width = OGR_Fld_GetWidth(cogr_fielddefn)
+                    if width:
+                        fmt = f":{width:d}"
+                    val = f"int32{fmt}"
 
-            elif fieldtypename in ('int32', 'int64'):
+            elif fieldtypename == "int64":
                 fmt = ""
                 width = OGR_Fld_GetWidth(cogr_fielddefn)
-
                 if width:
                     fmt = f":{width:d}"
+                val = f"int{fmt}"
 
-                val = 'int' + fmt
-
-            elif fieldtypename == 'str':
+            elif fieldtypename == "str":
                 fmt = ""
                 width = OGR_Fld_GetWidth(cogr_fielddefn)
-
                 if width:
                     fmt = f":{width:d}"
+                val = f"str{fmt}"
 
-                val = fieldtypename + fmt
+            else:
+                val = fieldtypename
 
             # Store the field name and description value.
             props[key] = val
@@ -1287,15 +1293,17 @@ cdef class WritingSession(Session):
 
                 # Convert 'long' to 'int'. See
                 # https://github.com/Toblerity/Fiona/issues/101.
-                if fiona.gdal_version.major >= 2 and value in ('int', 'long'):
+                if value in ('int', 'long'):
                     value = 'int64'
-                elif value == 'int':
-                    value = 'int32'
 
-                if value == 'bool':
+                elif value == 'bool':
                     value = 'int32'
                     field_subtype = OFSTBoolean
 
+                elif value == 'int16':
+                    value = 'int32'
+                    field_subtype = OFSTInt16
+
                 # Is there a field width/precision?
                 width = precision = None
                 if ':' in value:
@@ -1307,7 +1315,7 @@ cdef class WritingSession(Session):
                         width = int(fmt)
 
                     if value == 'int':
-                        if GDAL_VERSION_NUM >= 2000000 and (width == 0 or width >= 10):
+                        if width == 0 or width >= 10:
                             value = 'int64'
                         else:
                             value = 'int32'
@@ -1324,6 +1332,7 @@ cdef class WritingSession(Session):
                     if field_subtype != OFSTNone:
                         # subtypes are new in GDAL 2.x, ignored in 1.x
                         OGR_Fld_SetSubType(cogr_fielddefn, field_subtype)
+
                     exc_wrap_int(OGR_L_CreateField(self.cogr_layer, cogr_fielddefn, 1))
 
                 except (UnicodeEncodeError, CPLE_BaseError) as exc:

fiona/schema.pyx

@@ -74,6 +74,8 @@ def normalize_field_type(ftype):
         return ftype
     elif ftype == 'bool':
         return 'bool'
+    elif ftype == "int16":
+        return 'int32'
     elif ftype.startswith('int'):
         width = int((ftype.split(':')[1:] or ['0'])[0])
         if GDAL_VERSION_NUM >= 2000000 and (width == 0 or width >= 10):

tests/test_bytescollection.py

@@ -93,7 +93,7 @@ def test_schema(self):
         assert s["NAME"] == "str"
         assert s["URL"] == "str"
         assert s["STATE_FIPS"] == "str"
-        assert s["WILDRNP020"] == "int"
+        assert s["WILDRNP020"] == "int32"
 
     def test_closed_schema(self):
         # Schema is lazy too, never computed in this case. TODO?

tests/test_subtypes.py

@@ -1,26 +1,28 @@
+"""Tests of schema sub-types."""
+
+import os
+
 import fiona
 from fiona.model import Feature
 
 
-def test_read_bool_subtype(tmpdir):
+def test_read_bool_subtype(tmp_path):
     test_data = """{"type": "FeatureCollection", "features": [{"type": "Feature", "properties": {"bool": true, "not_bool": 1, "float": 42.5}, "geometry": null}]}"""
-    path = tmpdir.join("test_read_bool_subtype.geojson")
-    with open(str(path), "w") as f:
+    path = tmp_path.joinpath("test_read_bool_subtype.geojson")
+
+    with open(os.fspath(path), "w") as f:
         f.write(test_data)
 
-    with fiona.open(str(path), "r") as src:
+    with fiona.open(path, "r") as src:
         feature = next(iter(src))
 
-    if fiona.gdal_version.major >= 2:
-        assert type(feature["properties"]["bool"]) is bool
-    else:
-        assert type(feature["properties"]["bool"]) is int
+    assert type(feature["properties"]["bool"]) is bool
     assert isinstance(feature["properties"]["not_bool"], int)
     assert type(feature["properties"]["float"]) is float
 
 
-def test_write_bool_subtype(tmpdir):
-    path = tmpdir.join("test_write_bool_subtype.geojson")
+def test_write_bool_subtype(tmp_path):
+    path = tmp_path.joinpath("test_write_bool_subtype.geojson")
 
     schema = {
         "geometry": "Point",
@@ -42,14 +44,40 @@ def test_write_bool_subtype(tmpdir):
         }
     )
 
-    with fiona.open(str(path), "w", driver="GeoJSON", schema=schema) as dst:
+    with fiona.open(path, "w", driver="GeoJSON", schema=schema) as dst:
         dst.write(feature)
 
-    with open(str(path)) as f:
+    with open(os.fspath(path)) as f:
         data = f.read()
 
-    if fiona.gdal_version.major >= 2:
-        assert """"bool": true""" in data
-    else:
-        assert """"bool": 1""" in data
+    assert """"bool": true""" in data
     assert """"not_bool": 1""" in data
+
+
+def test_write_int16_subtype(tmp_path):
+    path = tmp_path.joinpath("test_write_bool_subtype.gpkg")
+
+    schema = {
+        "geometry": "Point",
+        "properties": {
+            "a": "int",
+            "b": "int16",
+        },
+    }
+
+    feature = Feature.from_dict(
+        **{
+            "geometry": None,
+            "properties": {
+                "a": 1,
+                "b": 2,
+            },
+        }
+    )
+
+    with fiona.open(path, "w", driver="GPKG", schema=schema) as colxn:
+        colxn.write(feature)
+
+    with fiona.open(path) as colxn:
+        assert colxn.schema["properties"]["a"] == "int"
+        assert colxn.schema["properties"]["b"] == "int16"