add include_print config function (#57)

Author: samuelcolvin

pyproject.toml

@@ -9,7 +9,7 @@ include = ["/README.md", "/Makefile", "/pytest_examples", "/tests"]
 
 [project]
 name = "pytest-examples"
-version = "0.0.15"
+version = "0.0.16"
 description = "Pytest plugin for testing examples in docstrings and markdown files."
 authors = [
     {name = "Samuel Colvin", email = "s@muelcolvin.com"},

pytest_examples/eval_example.py

@@ -9,7 +9,7 @@
 
 from .config import DEFAULT_LINE_LENGTH, ExamplesConfig
 from .lint import FormatError, black_check, black_format, ruff_check, ruff_format
-from .run_code import InsertPrintStatements, run_code
+from .run_code import IncludePrint, InsertPrintStatements, run_code
 
 if TYPE_CHECKING:
     from typing import Literal
@@ -29,6 +29,7 @@ def __init__(self, *, tmp_path: Path, pytest_request: pytest.FixtureRequest):
         self.to_update: list[CodeExample] = []
         self.config: ExamplesConfig = ExamplesConfig()
         self.print_callback: Callable[[str], str] | None = None
+        self.include_print: IncludePrint | None = None
 
     def set_config(
         self,
@@ -172,6 +173,7 @@ def _run(
             config=self.config,
             enable_print_mock=enable_print_mock,
             print_callback=self.print_callback,
+            include_print=self.include_print,
             module_globals=module_globals,
             call=call,
         )

pytest_examples/run_code.py

@@ -7,6 +7,7 @@
 import inspect
 import re
 import sys
+from collections.abc import Sequence
 from dataclasses import dataclass
 from importlib.abc import Loader
 from pathlib import Path
@@ -24,9 +25,10 @@
     from .config import ExamplesConfig
     from .find_examples import CodeExample
 
-__all__ = 'run_code', 'InsertPrintStatements'
+__all__ = 'run_code', 'InsertPrintStatements', 'IncludePrint'
 
 parent_frame_id = 4 if sys.version_info >= (3, 8) else 3
+IncludePrint = Callable[[Path, inspect.FrameInfo, Sequence[Any]], bool]
 
 
 def run_code(
@@ -37,6 +39,7 @@ def run_code(
     config: ExamplesConfig,
     enable_print_mock: bool,
     print_callback: Callable[[str], str] | None,
+    include_print: IncludePrint | None,
     module_globals: dict[str, Any] | None,
     call: str | None,
 ) -> tuple[InsertPrintStatements, dict[str, Any]]:
@@ -49,6 +52,7 @@ def run_code(
         config: The `ExamplesConfig` to use.
         enable_print_mock: If True, mock the `print` function.
         print_callback: If not None, a callback to call on `print`.
+        include_print: If not None, a function to call to determine if the print statement should be included.
         module_globals: The extra globals to add before calling the module.
         call: If not None, a (coroutine) function to call in the module.
 
@@ -63,7 +67,7 @@ def run_code(
     module = importlib.util.module_from_spec(spec)
 
     # does nothing if insert_print_statements is False
-    insert_print = InsertPrintStatements(python_file, config, enable_print_mock, print_callback)
+    insert_print = InsertPrintStatements(python_file, config, enable_print_mock, print_callback, include_print)
 
     if module_globals:
         module.__dict__.update(module_globals)
@@ -141,26 +145,40 @@ def not_print(*args):
 
 
 class MockPrintFunction:
-    def __init__(self, file: Path) -> None:
+    __slots__ = 'file', 'statements', 'include_print'
+
+    def __init__(self, file: Path, include_print: IncludePrint | None) -> None:
         self.file = file
         self.statements: list[PrintStatement] = []
+        self.include_print = include_print
 
     def __call__(self, *args: Any, sep: str = ' ', **kwargs: Any) -> None:
         frame = inspect.stack()[parent_frame_id]
 
-        if self.file.samefile(frame.filename):
+        if self._include_file(frame, args):
             # -1 to account for the line number being 1-indexed
             s = PrintStatement(frame.lineno, sep, [Arg(arg) for arg in args])
             self.statements.append(s)
 
+    def _include_file(self, frame: inspect.FrameInfo, args: Sequence[Any]) -> bool:
+        if self.include_print:
+            return self.include_print(self.file, frame, args)
+        else:
+            return self.file.samefile(frame.filename)
+
 
 class InsertPrintStatements:
     def __init__(
-        self, python_path: Path, config: ExamplesConfig, enable: bool, print_callback: Callable[[str], str] | None
+        self,
+        python_path: Path,
+        config: ExamplesConfig,
+        enable: bool,
+        print_callback: Callable[[str], str] | None,
+        include_print: IncludePrint | None,
     ):
         self.file = python_path
         self.config = config
-        self.print_func = MockPrintFunction(python_path) if enable else None
+        self.print_func = MockPrintFunction(python_path, include_print) if enable else None
         self.print_callback = print_callback
         self.patch = None
 

tests/test_insert_print.py

@@ -432,3 +432,22 @@ async def main():
 
     module_dict = eval_example.run_print_check(example, call='main')
     assert module_dict['main_called']
+
+
+def test_custom_include_print(tmp_path, eval_example):
+    # note this file is no written here as it's not required
+    md_file = tmp_path / 'test.md'
+    python_code = """
+print('yes')
+#> yes
+print('no')
+"""
+    example = CodeExample.create(python_code, path=md_file)
+    eval_example.set_config(line_length=30)
+
+    def custom_include_print(path, frame, args):
+        return 'yes' in args
+
+    eval_example.include_print = custom_include_print
+
+    eval_example.run_print_check(example, call='main')