Added addressable page per row

Refs #1 - only exists for tables with introspectable primary keys.

Still need to link to this page.

Also added first unit tests - refs #9

test_helpers.py

@@ -0,0 +1,46 @@
+import app
+import pytest
+import sqlite3
+
+
+@pytest.mark.parametrize('path,expected', [
+    ('foo', ['foo']),
+    ('foo,bar', ['foo', 'bar']),
+    ('123,433,112', ['123', '433', '112']),
+    ('123%2C433,112', ['123,433', '112']),
+    ('123%2F433%2F112', ['123/433/112']),
+])
+def test_compound_pks_from_path(path, expected):
+    assert expected == app.compound_pks_from_path(path)
+
+
+@pytest.mark.parametrize('sql,table,expected_keys', [
+    ('''
+        CREATE TABLE `Compound` (
+            A varchar(5) NOT NULL,
+            B varchar(10) NOT NULL,
+            PRIMARY KEY (A, B)
+        );
+    ''', 'Compound', ['A', 'B']),
+    ('''
+        CREATE TABLE `Compound2` (
+            A varchar(5) NOT NULL,
+            B varchar(10) NOT NULL,
+            PRIMARY KEY (B, A)
+        );
+    ''', 'Compound2', ['B', 'A']),
+])
+def test_pks_for_table(sql, table, expected_keys):
+    conn = sqlite3.connect(':memory:')
+    conn.execute(sql)
+    actual = app.pks_for_table(conn, table)
+    assert expected_keys == actual
+
+
+@pytest.mark.parametrize('row,pks,expected_path', [
+    ({'A': 'foo', 'B': 'bar'}, ['A', 'B'], 'foo,bar'),
+    ({'A': 'f,o', 'B': 'bar'}, ['A', 'B'], 'f%2Co,bar'),
+])
+def test_path_from_row_pks(row, pks, expected_path):
+    actual_path = app.path_from_row_pks(row, pks)
+    assert expected_path == actual_path