Add compact option to force a more compact formatting (fixes #783).

Author: andialbrecht

CHANGELOG

@@ -1,6 +1,11 @@
 Development Version
 -------------------
 
+Enhancements
+
+* New "compact" option for formatter. If set, the formatter tries to produce
+  a more compact output by avoiding some line breaks (issue783).
+
 Bug Fixes
 
 * The strip comments filter was a bit greedy and removed too much
@@ -23,7 +28,7 @@ Notable Changes
   https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-2m57-hf25-phgg
   The vulnerability was discovered by @uriyay-jfrog. Thanks for reporting!
 
-Enhancements:
+Enhancements
 
 * Splitting statements now allows to remove the semicolon at the end.
   Some database backends love statements without semicolon (issue742).

docs/source/api.rst

@@ -62,6 +62,9 @@ The :meth:`~sqlparse.format` function accepts the following keyword arguments.
   The column limit (in characters) for wrapping comma-separated lists. If unspecified, it
   puts every item in the list on its own line.
 
+``compact```
+  If ``True`` the formatter tries to produce more compact output.
+
 ``output_format``
   If given the output is additionally formatted to be used as a variable
   in a programming language. Allowed values are "python" and "php".

sqlparse/cli.py

@@ -138,7 +138,14 @@ def create_parser():
         default=False,
         type=bool,
         help='Insert linebreak before comma (default False)')
-
+    
+    group.add_argument(
+        '--compact',
+        dest='compact',
+        default=False,
+        type=bool,
+        help='Try to produce more compact output (default False)')
+    
     group.add_argument(
         '--encoding',
         dest='encoding',

sqlparse/filters/reindent.py

@@ -12,7 +12,7 @@
 class ReindentFilter:
     def __init__(self, width=2, char=' ', wrap_after=0, n='\n',
                  comma_first=False, indent_after_first=False,
-                 indent_columns=False):
+                 indent_columns=False, compact=False):
         self.n = n
         self.width = width
         self.char = char
@@ -21,6 +21,7 @@ def __init__(self, width=2, char=' ', wrap_after=0, n='\n',
         self.wrap_after = wrap_after
         self.comma_first = comma_first
         self.indent_columns = indent_columns
+        self.compact = compact
         self._curr_stmt = None
         self._last_stmt = None
         self._last_func = None
@@ -196,15 +197,20 @@ def _process_case(self, tlist):
         with offset(self, self._get_offset(tlist[0])):
             with offset(self, self._get_offset(first)):
                 for cond, value in iterable:
-                    token = value[0] if cond is None else cond[0]
-                    tlist.insert_before(token, self.nl())
+                    str_cond = ''.join(str(x) for x in cond or [])
+                    str_value = ''.join(str(x) for x in value)
+                    end_pos = self.offset + 1 + len(str_cond) + len(str_value)
+                    if (not self.compact 
+                        and end_pos > self.wrap_after):
+                        token = value[0] if cond is None else cond[0]
+                        tlist.insert_before(token, self.nl())
 
                 # Line breaks on group level are done. let's add an offset of
                 # len "when ", "then ", "else "
                 with offset(self, len("WHEN ")):
                     self._process_default(tlist)
             end_idx, end = tlist.token_next_by(m=sql.Case.M_CLOSE)
-            if end_idx is not None:
+            if end_idx is not None and not self.compact:
                 tlist.insert_before(end_idx, self.nl())
 
     def _process_values(self, tlist):

sqlparse/formatter.py

@@ -115,6 +115,11 @@ def validate_options(options):
     if comma_first not in [True, False]:
         raise SQLParseError('comma_first requires a boolean value')
     options['comma_first'] = comma_first
+    
+    compact = options.get('compact', False)
+    if compact not in [True, False]:
+        raise SQLParseError('compact requires a boolean value')
+    options['compact'] = compact
 
     right_margin = options.get('right_margin')
     if right_margin is not None:
@@ -171,7 +176,8 @@ def build_filter_stack(stack, options):
                 indent_after_first=options['indent_after_first'],
                 indent_columns=options['indent_columns'],
                 wrap_after=options['wrap_after'],
-                comma_first=options['comma_first']))
+                comma_first=options['comma_first'],
+                compact=options['compact'],))
 
     if options.get('reindent_aligned', False):
         stack.enable_grouping()

tests/test_format.py

@@ -734,3 +734,14 @@ def test_format_json_ops():  # issue542
         "select foo->'bar', foo->'bar';", reindent=True)
     expected = "select foo->'bar',\n       foo->'bar';"
     assert formatted == expected
+    
+    
+@pytest.mark.parametrize('sql, expected_normal, expected_compact', [
+    ('case when foo then 1 else bar end',
+     'case\n    when foo then 1\n    else bar\nend',
+     'case when foo then 1 else bar end')])
+def test_compact(sql, expected_normal, expected_compact):  # issue783
+    formatted_normal = sqlparse.format(sql, reindent=True)
+    formatted_compact = sqlparse.format(sql, reindent=True, compact=True)
+    assert formatted_normal == expected_normal
+    assert formatted_compact == expected_compact