Fix #34 (ignore marked lines)

Update tests

allowed.py

@@ -376,6 +376,13 @@ def location(line: int, line_cell_map: list) -> tuple[int, int]:
     return line_cell_map[line] if line_cell_map else (0, line)
 
 
+def ignore(node: ast.AST, source: list[str]) -> bool:
+    """Return True if node is on a line to be ignored."""
+    return hasattr(node, "lineno") and source[node.lineno - 1].rstrip().endswith(
+        "# allowed"
+    )
+
+
 # ----- main functions -----
 
 
@@ -389,9 +396,11 @@ def check_tree(
     """Check if tree only uses allowed constructs. Add violations to errors."""
     language, options, imports, functions, methods = constructs
     for node in ast.walk(tree):
-        # if a node has no line number, handle it via its parent
+        # If a node has no line number, handle it via its parent.
         if isinstance(node, NO_LINE):
             pass
+        elif ignore(node, source):
+            pass
         elif isinstance(node, (ast.BinOp, ast.UnaryOp, ast.BoolOp)):
             if not isinstance(node.op, language):
                 cell, line = location(node.lineno, line_cell_map)
@@ -408,7 +417,7 @@ def check_tree(
                 cell, line = location(node.lineno, line_cell_map)
                 message = CONCRETE.get(type(node), "unknown construct")
             else:
-                # if a node has no line number, report it for inclusion in NO_LINE
+                # If a node has no line number, report it for inclusion in NO_LINE.
                 cell, line = 0, 0
                 message = f"unknown construct {str(node)} at unknown line"
             errors.append((cell, line, message))

sample.py

@@ -14,7 +14,7 @@
 f = 9e5 + 8.3e-2 - 7_000 * 6 / -5 // 4 % 3**2
 1 << 3
 abs(min(1, max(2, 3)))
-f.is_integer()
+f.is_integer()  # allowed
 
 # Booleans
 True and False or not True
@@ -30,7 +30,7 @@
 s.upper()
 
 # Lists
-l = [] + list("abc")
+l = [] + list("abc") + [letter for letter in "abc"]
 l.sort(reverse=True)
 l.append(1)
 l.pop()
@@ -41,11 +41,11 @@
 
 # Operations common to all sequences
 t[2] not in l[:3:-1] * 2
-t.index("a")
-l.count(None)
+# The following allows all constructs on the same line.
+l.count(t.index(1))  # allowed
 
 # Sets
-items = set() | {1, 2, 3} & {2, 3} ^ {3, 4} - {4, 5}
+items = set() | {1, 2, 3} & {2, 3} ^ {3, 4} - {i for i in range(1, 10, 2)}
 items.add(items.pop())
 items.discard(9)
 items.union(l)
@@ -58,7 +58,7 @@
     print(key, value)
 
 # Control flow statements
-try:
+try:  # allowed
     for i in range(1, 5):
         while i < 6:
             if i == 0:

tests/sample-py-m.txt

@@ -1,14 +1,12 @@
 sample.py:8: types
 sample.py:9: choice
 sample.py:15: <<
-sample.py:17: float.is_integer()
 sample.py:22: if expression
 sample.py:29: f-string
 sample.py:30: str.upper()
-sample.py:44: tuple.index()
-sample.py:45: list.count()
+sample.py:33: list comprehension
 sample.py:48: ^
-sample.py:61: try
+sample.py:48: set comprehension
 sample.py:67: break
 sample.py:70: while-else
 sample.py:71: continue

tests/sample-py.txt

@@ -3,8 +3,9 @@ sample.py:9: choice
 sample.py:15: <<
 sample.py:22: if expression
 sample.py:29: f-string
+sample.py:33: list comprehension
 sample.py:48: ^
-sample.py:61: try
+sample.py:48: set comprehension
 sample.py:67: break
 sample.py:70: while-else
 sample.py:71: continue