| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | """Ensures all fields in a config dataclass have default values |
| 4 | and that each field has a docstring. |
| 5 | """ |
| 6 | |
| 7 | import ast |
| 8 | import inspect |
| 9 | import sys |
| 10 | from itertools import pairwise |
| 11 | |
| 12 | import regex as re |
| 13 | |
| 14 | |
| 15 | def get_attr_docs(cls_node: ast.ClassDef) -> dict[str, str]: |
| 16 | """Get any docstrings placed after attribute assignments in a class body. |
| 17 | |
| 18 | Adapted from https://davidism.com/attribute-docstrings/ |
| 19 | https://davidism.com/mit-license/ |
| 20 | """ |
| 21 | out = {} |
| 22 | |
| 23 | # Consider each pair of nodes. |
| 24 | for a, b in pairwise(cls_node.body): |
| 25 | # Must be an assignment then a constant string. |
| 26 | if ( |
| 27 | not isinstance(a, (ast.Assign, ast.AnnAssign)) |
| 28 | or not isinstance(b, ast.Expr) |
| 29 | or not isinstance(b.value, ast.Constant) |
| 30 | or not isinstance(b.value.value, str) |
| 31 | ): |
| 32 | continue |
| 33 | |
| 34 | doc = inspect.cleandoc(b.value.value) |
| 35 | |
| 36 | # An assignment can have multiple targets (a = b = v), but an |
| 37 | # annotated assignment only has one target. |
| 38 | targets = a.targets if isinstance(a, ast.Assign) else [a.target] |
| 39 | |
| 40 | for target in targets: |
| 41 | # Must be assigning to a plain name. |
| 42 | if not isinstance(target, ast.Name): |
| 43 | continue |
| 44 | |
| 45 | out[target.id] = doc |
| 46 | |
| 47 | return out |
| 48 | |
| 49 | |
| 50 | class ConfigValidator(ast.NodeVisitor): |
| 51 | def __init__(self): ... |
| 52 | |
| 53 | def visit_ClassDef(self, node): |
| 54 | # Validate classes with a @config decorator |
| 55 | decorators = set() |
| 56 | for decorator in node.decorator_list: |
| 57 | if isinstance(decorator, ast.Call): |
| 58 | decorator = decorator.func |
| 59 | if isinstance(decorator, ast.Name) and decorator.id == "config": |
| 60 | decorators.add(decorator.id) |
| 61 | |
| 62 | if decorators == {"config"}: |
| 63 | validate_class(node) |
| 64 | elif "config" in decorators: |
| 65 | fail(f"config decorator for {node.name} should be used alone", node) |
| 66 | |
| 67 | self.generic_visit(node) |
| 68 | |
| 69 | |
| 70 | def validate_class(class_node: ast.ClassDef): |
| 71 | attr_docs = get_attr_docs(class_node) |
| 72 | |
| 73 | for stmt in class_node.body: |
| 74 | # A field is defined as a class variable that has a type annotation. |
| 75 | if isinstance(stmt, ast.AnnAssign): |
| 76 | # Skip ClassVar and InitVar |
| 77 | # see https://docs.python.org/3/library/dataclasses.html#class-variables |
| 78 | # and https://docs.python.org/3/library/dataclasses.html#init-only-variables |
| 79 | if ( |
| 80 | isinstance(stmt.annotation, ast.Subscript) |
| 81 | and isinstance(stmt.annotation.value, ast.Name) |
| 82 | and stmt.annotation.value.id in {"ClassVar", "InitVar"} |
| 83 | ): |
| 84 | continue |
| 85 | |
| 86 | if isinstance(stmt.target, ast.Name): |
| 87 | field_name = stmt.target.id |
| 88 | if stmt.value is None: |
| 89 | fail( |
| 90 | f"Field '{field_name}' in {class_node.name} must have " |
| 91 | "a default value.", |
| 92 | stmt, |
| 93 | ) |
| 94 | |
| 95 | if field_name not in attr_docs: |
| 96 | fail( |
| 97 | f"Field '{field_name}' in {class_node.name} must have " |
| 98 | "a docstring.", |
| 99 | stmt, |
| 100 | ) |
| 101 | |
| 102 | if ( |
| 103 | isinstance(stmt.annotation, ast.Subscript) |
| 104 | and isinstance(stmt.annotation.value, ast.Name) |
| 105 | and stmt.annotation.value.id == "Union" |
| 106 | and isinstance(stmt.annotation.slice, ast.Tuple) |
| 107 | ): |
| 108 | args = stmt.annotation.slice.elts |
| 109 | literal_args = [ |
| 110 | arg |
| 111 | for arg in args |
| 112 | if isinstance(arg, ast.Subscript) |
| 113 | and isinstance(arg.value, ast.Name) |
| 114 | and arg.value.id == "Literal" |
| 115 | ] |
| 116 | if len(literal_args) > 1: |
| 117 | fail( |
| 118 | f"Field '{field_name}' in {class_node.name} must " |
| 119 | "use a single " |
| 120 | "Literal type. Please use 'Literal[Literal1, " |
| 121 | "Literal2]' instead of 'Union[Literal1, Literal2]'" |
| 122 | ".", |
| 123 | stmt, |
| 124 | ) |
| 125 | |
| 126 | |
| 127 | def validate_ast(tree: ast.stmt): |
| 128 | ConfigValidator().visit(tree) |
| 129 | |
| 130 | |
| 131 | def validate_file(file_path: str): |
| 132 | try: |
| 133 | print(f"Validating {file_path} config dataclasses ", end="") |
| 134 | with open(file_path, encoding="utf-8") as f: |
| 135 | source = f.read() |
| 136 | |
| 137 | tree = ast.parse(source, filename=file_path) |
| 138 | validate_ast(tree) |
| 139 | except ValueError as e: |
| 140 | print(e) |
| 141 | raise SystemExit(1) from e |
| 142 | else: |
| 143 | print("✅") |
| 144 | |
| 145 | |
| 146 | def fail(message: str, node: ast.stmt): |
| 147 | raise ValueError(f"❌ line({node.lineno}): {message}") |
| 148 | |
| 149 | |
| 150 | def main(): |
| 151 | for filename in sys.argv[1:]: |
| 152 | # Only run for Python files in vllm/ or tests/ |
| 153 | if not re.match(r"^(vllm|tests)/.*\.py$", filename): |
| 154 | continue |
| 155 | # Only run if the file contains @config |
| 156 | with open(filename, encoding="utf-8") as f: |
| 157 | if "@config" in f.read(): |
| 158 | validate_file(filename) |
| 159 | |
| 160 | |
| 161 | if __name__ == "__main__": |
| 162 | main() |