fix statements finding for multiple debug calls in the same block (#61)

* fix sttatement finding for multiple debug calls in the same block

* different for 3.8 and 3.7

* coverage

Author: samuelcolvin

devtools/debug.py

@@ -317,23 +317,19 @@ def _statement_range(call_frame: 'FrameType', func_name: str) -> 'Tuple[int, int
         first_line = None
         last_line = None
 
-        for instr in instructions:
+        for instr in instructions:  # pragma: no branch
             if instr.starts_line:
                 if instr.opname in {'LOAD_GLOBAL', 'LOAD_NAME'} and instr.argval == func_name:
                     first_line = instr.starts_line
-                    break
                 elif instr.opname == 'LOAD_GLOBAL' and instr.argval == 'debug':
                     if next(instructions).argval == func_name:
                         first_line = instr.starts_line
-                        break
+            if instr.offset == call_frame.f_lasti:
+                break
 
         if first_line is None:
             raise IntrospectionError('error parsing code, unable to find "{}" function statement'.format(func_name))
 
-        for instr in instructions:  # pragma: no branch
-            if instr.offset == call_frame.f_lasti:
-                break
-
         for instr in instructions:
             if instr.starts_line:
                 last_line = instr.starts_line - 1

tests/test_main.py

@@ -258,3 +258,28 @@ def __getattr__(self, item):
         "    b: <tests.test_main.test_pretty_error.<locals>.BadPretty object at 0x000> (BadPretty)\n"
         "    !!! error pretty printing value: RuntimeError('this is an error')"
     )
+
+
+@pytest.mark.skipif(sys.version_info >= (3, 8), reason='different between 3.7 and 3.8')
+def test_multiple_debugs_37():
+    debug.format([i * 2 for i in range(2)])
+    debug.format([i * 2 for i in range(2)])
+    v = debug.format([i * 2 for i in range(2)])
+    s = re.sub(r':\d{2,}', ':<line no>', str(v))
+    assert s == (
+        'tests/test_main.py:<line no> test_multiple_debugs_37\n'
+        '    [i * 2 for i in range(2)]: [0, 2] (list) len=2'
+    )
+
+
+@pytest.mark.skipif(sys.version_info < (3, 8), reason='different between 3.7 and 3.8')
+def test_multiple_debugs_38():
+    debug.format([i * 2 for i in range(2)])
+    debug.format([i * 2 for i in range(2)])
+    v = debug.format([i * 2 for i in range(2)])
+    s = re.sub(r':\d{2,}', ':<line no>', str(v))
+    # FIXME there's an extraneous bracket here, due to some error building code from the ast
+    assert s == (
+        'tests/test_main.py:<line no> test_multiple_debugs_38\n'
+        '    ([i * 2 for i in range(2)]: [0, 2] (list) len=2'
+    )