From c04db182d1e84af7044027800178ae1aed2f6a51 2014-10-22 17:26:14
From: MinRK <benjaminrk@gmail.com>
Date: 2014-10-22 17:26:14
Subject: [PATCH] don't pick up tokens right of cursor

inspection of `foo(|a` was picking up 'a'
instead of 'foo' due to an off by one error

---

diff --git a/IPython/utils/tests/test_tokenutil.py b/IPython/utils/tests/test_tokenutil.py
index 4d7084a..024c5c7 100644
--- a/IPython/utils/tests/test_tokenutil.py
+++ b/IPython/utils/tests/test_tokenutil.py
@@ -18,8 +18,8 @@ def expect_token(expected, cell, cursor_pos):
     line_with_cursor = '%s|%s' % (line[:column], line[column:])
     line
     nt.assert_equal(token, expected,
-        "Excpected %r, got %r in: %s" % (
-        expected, token, line_with_cursor)
+        "Expected %r, got %r in: %r (pos %i)" % (
+        expected, token, line_with_cursor, cursor_pos)
     )
 
 def test_simple(): 
@@ -30,7 +30,14 @@ def test_simple():
 def test_function():
     cell = "foo(a=5, b='10')"
     expected = 'foo'
-    for i in (6,7,8,10,11,12):
+    # up to `foo(|a=`
+    for i in range(cell.find('a=') + 1):
+        expect_token("foo", cell, i)
+    # find foo after `=`
+    for i in [cell.find('=') + 1, cell.rfind('=') + 1]:
+        expect_token("foo", cell, i)
+    # in between `5,|` and `|b=`
+    for i in range(cell.find(','), cell.find('b=')):
         expect_token("foo", cell, i)
 
 def test_multiline():
@@ -39,25 +46,25 @@ def test_multiline():
         'b = hello("string", there)'
     ])
     expected = 'hello'
-    start = cell.index(expected)
+    start = cell.index(expected) + 1
     for i in range(start, start + len(expected)):
         expect_token(expected, cell, i)
     expected = 'there'
-    start = cell.index(expected)
+    start = cell.index(expected) + 1
     for i in range(start, start + len(expected)):
         expect_token(expected, cell, i)
 
 def test_attrs():
     cell = "foo(a=obj.attr.subattr)"
     expected = 'obj'
-    idx = cell.find('obj')
+    idx = cell.find('obj') + 1
     for i in range(idx, idx + 3):
         expect_token(expected, cell, i)
-    idx = idx + 4
+    idx = cell.find('.attr') + 2
     expected = 'obj.attr'
     for i in range(idx, idx + 4):
         expect_token(expected, cell, i)
-    idx = idx + 5
+    idx = cell.find('.subattr') + 2
     expected = 'obj.attr.subattr'
     for i in range(idx, len(cell)):
         expect_token(expected, cell, i)
diff --git a/IPython/utils/tokenutil.py b/IPython/utils/tokenutil.py
index 9a14e04..8cd24bf 100644
--- a/IPython/utils/tokenutil.py
+++ b/IPython/utils/tokenutil.py
@@ -47,7 +47,9 @@ def token_at_cursor(cell, cursor_pos=0):
         # token, text, start, end, line = tup
         start_col = tok.start[1]
         end_col = tok.end[1]
-        if offset + start_col > cursor_pos:
+        # allow '|foo' to find 'foo' at the beginning of a line
+        boundary = cursor_pos + 1 if start_col == 0 else cursor_pos
+        if offset + start_col >= boundary:
             # current token starts after the cursor,
             # don't consume it
             break