add test for new postcode import function

test/python/test_tools_postcodes.py

@@ -0,0 +1,50 @@
+"""
+Tests for functions to maintain the artificial postcode table.
+"""
+
+import pytest
+
+from nominatim.tools import postcodes
+
+@pytest.fixture
+def postcode_table(temp_db_with_extensions, temp_db_cursor, table_factory,
+                   placex_table, word_table):
+    table_factory('location_postcode',
+                  """ place_id BIGINT,
+                      parent_place_id BIGINT,
+                      rank_search SMALLINT,
+                      rank_address SMALLINT,
+                      indexed_status SMALLINT,
+                      indexed_date TIMESTAMP,
+                      country_code varchar(2),
+                      postcode TEXT,
+                      geometry GEOMETRY(Geometry, 4326)""")
+    temp_db_cursor.execute('CREATE SEQUENCE seq_place')
+    temp_db_cursor.execute("""CREATE OR REPLACE FUNCTION getorcreate_postcode_id(postcode TEXT)
+                              RETURNS INTEGER AS $$ BEGIN RETURN 1; END; $$ LANGUAGE plpgsql;
+                           """)
+
+
+def test_import_postcodes_empty(dsn, temp_db_cursor, postcode_table, tmp_path):
+    postcodes.import_postcodes(dsn, tmp_path)
+
+    assert temp_db_cursor.table_exists('gb_postcode')
+    assert temp_db_cursor.table_exists('us_postcode')
+    assert temp_db_cursor.table_rows('location_postcode') == 0
+
+
+def test_import_postcodes_from_placex(dsn, temp_db_cursor, postcode_table, tmp_path):
+    temp_db_cursor.execute("""
+        INSERT INTO placex (place_id, country_code, address, geometry)
+          VALUES (1, 'xx', '"postcode"=>"9486"', 'SRID=4326;POINT(10 12)')
+    """)
+
+    postcodes.import_postcodes(dsn, tmp_path)
+
+    rows = temp_db_cursor.row_set(""" SELECT postcode, country_code,
+                                      ST_X(geometry), ST_Y(geometry)
+                                      FROM location_postcode""")
+    print(rows)
+    assert len(rows) == 1
+    assert rows == set((('9486', 'xx', 10, 12), ))
+