Add some tests for the environment functionality

unit_test/environment_test.py

@@ -0,0 +1,35 @@
+from cibuildwheel.environment import parse_environment
+
+
+def test_basic_parsing():
+    environment_recipe = parse_environment('VAR=1 VBR=2')
+
+    environment_dict = environment_recipe.as_dictionary(
+        prev_environment={},
+        shell=lambda cmd: '')
+    environment_cmds = environment_recipe.as_shell_commands()
+
+    assert environment_dict == {'VAR': '1', 'VBR': '2'}
+    assert environment_cmds == ['export VAR=1', 'export VBR=2']
+
+def test_quotes():
+    environment_recipe = parse_environment('A=1 VAR="1 NOT_A_VAR=2" VBR=\'vbr\'')
+
+    environment_dict = environment_recipe.as_dictionary(
+        prev_environment={},
+        shell=lambda cmd: '')
+    environment_cmds = environment_recipe.as_shell_commands()
+
+    assert environment_dict == {'A': '1', 'VAR': '1 NOT_A_VAR=2', 'VBR': 'vbr'}
+    assert environment_cmds == ['export A=1', 'export VAR="1 NOT_A_VAR=2"', 'export ABR=vbr']
+
+def test_inheritance():
+    environment_recipe = parse_environment('PATH=$PATH:/usr/local/bin')
+
+    environment_dict = environment_recipe.as_dictionary(
+        prev_environment={'PATH': '/usr/bin'},
+        shell=lambda cmd: '')
+    environment_cmds = environment_recipe.as_shell_commands()
+
+    assert environment_dict == {'PATH': '/usr/bin:/usr/local/bin'}
+    assert environment_cmds == ['export PATH=$PATH:/usr/local/bin']