Bugfix: parse_line incorrectly strips "export " prefix (theskumar#125)

PiDelport · theskumar · commit 4b1686fcef0f · 2018-08-06T00:03:50.000+05:30
* parse_line: Add failing tests for "export" stripping

* parse_line: Strip using partition rather than lstrip

This avoids accidentally stripping additional leading characters from
the variable name.
diff --git a/dotenv/main.py b/dotenv/main.py
@@ -31,7 +31,7 @@ def parse_line(line):
     k, v = line.split('=', 1)
 
     if k.startswith('export '):
-        k = k.lstrip('export ')
+        (_, _, k) = k.partition('export ')
 
     # Remove any leading and trailing spaces in key, value
     k, v = k.strip(), v.strip()
diff --git a/tests/test_core.py b/tests/test_core.py
@@ -24,6 +24,8 @@
     ("a=b space ", ('a', 'b space')),
     ("a='b space '", ('a', 'b space ')),
     ('a="b space "', ('a', 'b space ')),
+    ("export export_spam=1", ("export_spam", "1")),
+    ("export port=8000", ("port", "8000")),
 ])
 def test_parse_line(test_input, expected):
     assert parse_line(test_input) == expected
