ninja.py: fix the new test and pass the test

From a patch from Elazar Leibovich <elazarl@gmail.com>.

2 files changed, 36 insertions, 13 deletions

diff --git a/misc/ninja.py b/misc/ninja.py
index 38b13c9..2c9d818 100644
--- a/misc/ninja.py
+++ b/misc/ninja.py
@@ -55,12 +55,28 @@ class Writer(object):
         return outputs
 
     def _line(self, text, indent=0):
+        """Write 'text' word-wrapped at self.width characters."""
+        leading_space = '  ' * indent
         while len(text) > self.width:
-            space = text.rfind(' ', 0, self.width - 4)
-            assert space != -1  # TODO: handle if no space found.
-            self.output.write(text[0:space] + ' $\n')
-            text = '  ' * (indent+2) + text[space:].lstrip()
-        self.output.write(text + '\n')
+            # The text is too wide; wrap if possible.
+
+            # Find the rightmost space that would obey our width constraint.
+            available_space = self.width - len(leading_space) - len(' $')
+            space = text.rfind(' ', 0, available_space)
+            if space < 0:
+                # No such space; just use the first space we can find.
+                space = text.find(' ', available_space)
+            if space < 0:
+                # Give up on breaking.
+                break
+
+            self.output.write(leading_space + text[0:space] + ' $\n')
+            text = text[space+1:]
+
+            # Subsequent lines are continuations, so indent them.
+            leading_space = '  ' * (indent+2)
+
+        self.output.write(leading_space + text + '\n')
 
     def _as_list(self, input):
         if input is None:
diff --git a/misc/ninja_test.py b/misc/ninja_test.py
index 555f189..44c6230 100755
--- a/misc/ninja_test.py
+++ b/misc/ninja_test.py
@@ -20,26 +20,33 @@ from StringIO import StringIO
 import ninja
 
 LONGWORD = 'a' * 10
+INDENT = '    '
 
 class TestLineWordWrap(unittest.TestCase):
     def setUp(self):
         self.out = StringIO()
-        self.n = ninja.Writer(self.out, width=5)
+        self.n = ninja.Writer(self.out, width=8)
 
     def test_single_long_word(self):
         # We shouldn't wrap a single long word.
         self.n._line(LONGWORD)
-        self.assertEqual(LONGWORD, self.out.getvalue())
+        self.assertEqual(LONGWORD + '\n', self.out.getvalue())
 
     def test_few_long_words(self):
         # We should wrap a line where the second word is overlong.
         self.n._line(' '.join(['x', LONGWORD, 'y']))
-        self.assertEqual('x \n' + LONGWORD + '\ny', self.out.getvalue())
-
-    def test_few_long_words_space(self):
-        # We should also wrap indented lines.
-        self.n._line(' '.join(['x', LONGWORD, 'y']), indent=2)
-        self.assertEqual('x \n  ' + LONGWORD + '\n  y', self.out.getvalue())
+        self.assertEqual(' $\n'.join(['x',
+                                      INDENT + LONGWORD,
+                                      INDENT + 'y']) + '\n',
+                         self.out.getvalue())
+
+    def test_few_long_words_indented(self):
+        # Check wrapping in the presence of indenting.
+        self.n._line(' '.join(['x', LONGWORD, 'y']), indent=1)
+        self.assertEqual(' $\n'.join(['  ' + 'x',
+                                      '  ' + INDENT + LONGWORD,
+                                      '  ' + INDENT + 'y']) + '\n',
+                         self.out.getvalue())
 
 if __name__ == '__main__':
     unittest.main()