Edit File: plugin_support.py
# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt """Support for plugins.""" from __future__ import annotations import os import os.path import sys from types import FrameType from typing import Any, Dict, Iterable, Iterator, List, Optional, Set, Tuple, Union from coverage.exceptions import PluginError from coverage.misc import isolate_module from coverage.plugin import CoveragePlugin, FileTracer, FileReporter from coverage.types import ( TArc, TConfigurable, TDebugCtl, TLineNo, TPluginConfig, TSourceTokenLines, ) os = isolate_module(os) class Plugins: """The currently loaded collection of coverage.py plugins.""" def __init__(self) -> None: self.order: List[CoveragePlugin] = [] self.names: Dict[str, CoveragePlugin] = {} self.file_tracers: List[CoveragePlugin] = [] self.configurers: List[CoveragePlugin] = [] self.context_switchers: List[CoveragePlugin] = [] self.current_module: Optional[str] = None self.debug: Optional[TDebugCtl] @classmethod def load_plugins( cls, modules: Iterable[str], config: TPluginConfig, debug: Optional[TDebugCtl] = None, ) -> Plugins: """Load plugins from `modules`. Returns a Plugins object with the loaded and configured plugins. """ plugins = cls() plugins.debug = debug for module in modules: plugins.current_module = module __import__(module) mod = sys.modules[module] coverage_init = getattr(mod, "coverage_init", None) if not coverage_init: raise PluginError( f"Plugin module {module!r} didn't define a coverage_init function" ) options = config.get_plugin_options(module) coverage_init(plugins, options) plugins.current_module = None return plugins def add_file_tracer(self, plugin: CoveragePlugin) -> None: """Add a file tracer plugin. `plugin` is an instance of a third-party plugin class. It must implement the :meth:`CoveragePlugin.file_tracer` method. """ self._add_plugin(plugin, self.file_tracers) def add_configurer(self, plugin: CoveragePlugin) -> None: """Add a configuring plugin. `plugin` is an instance of a third-party plugin class. It must implement the :meth:`CoveragePlugin.configure` method. """ self._add_plugin(plugin, self.configurers) def add_dynamic_context(self, plugin: CoveragePlugin) -> None: """Add a dynamic context plugin. `plugin` is an instance of a third-party plugin class. It must implement the :meth:`CoveragePlugin.dynamic_context` method. """ self._add_plugin(plugin, self.context_switchers) def add_noop(self, plugin: CoveragePlugin) -> None: """Add a plugin that does nothing. This is only useful for testing the plugin support. """ self._add_plugin(plugin, None) def _add_plugin( self, plugin: CoveragePlugin, specialized: Optional[List[CoveragePlugin]], ) -> None: """Add a plugin object. `plugin` is a :class:`CoveragePlugin` instance to add. `specialized` is a list to append the plugin to. """ plugin_name = f"{self.current_module}.{plugin.__class__.__name__}" if self.debug and self.debug.should("plugin"): self.debug.write(f"Loaded plugin {self.current_module!r}: {plugin!r}") labelled = LabelledDebug(f"plugin {self.current_module!r}", self.debug) plugin = DebugPluginWrapper(plugin, labelled) plugin._coverage_plugin_name = plugin_name plugin._coverage_enabled = True self.order.append(plugin) self.names[plugin_name] = plugin if specialized is not None: specialized.append(plugin) def __bool__(self) -> bool: return bool(self.order) def __iter__(self) -> Iterator[CoveragePlugin]: return iter(self.order) def get(self, plugin_name: str) -> CoveragePlugin: """Return a plugin by name.""" return self.names[plugin_name] class LabelledDebug: """A Debug writer, but with labels for prepending to the messages.""" def __init__(self, label: str, debug: TDebugCtl, prev_labels: Iterable[str] = ()): self.labels = list(prev_labels) + [label] self.debug = debug def add_label(self, label: str) -> LabelledDebug: """Add a label to the writer, and return a new `LabelledDebug`.""" return LabelledDebug(label, self.debug, self.labels) def message_prefix(self) -> str: """The prefix to use on messages, combining the labels.""" prefixes = self.labels + [""] return ":\n".join(" "*i+label for i, label in enumerate(prefixes)) def write(self, message: str) -> None: """Write `message`, but with the labels prepended.""" self.debug.write(f"{self.message_prefix()}{message}") class DebugPluginWrapper(CoveragePlugin): """Wrap a plugin, and use debug to report on what it's doing.""" def __init__(self, plugin: CoveragePlugin, debug: LabelledDebug) -> None: super().__init__() self.plugin = plugin self.debug = debug def file_tracer(self, filename: str) -> Optional[FileTracer]: tracer = self.plugin.file_tracer(filename) self.debug.write(f"file_tracer({filename!r}) --> {tracer!r}") if tracer: debug = self.debug.add_label(f"file {filename!r}") tracer = DebugFileTracerWrapper(tracer, debug) return tracer def file_reporter(self, filename: str) -> Union[FileReporter, str]: reporter = self.plugin.file_reporter(filename) assert isinstance(reporter, FileReporter) self.debug.write(f"file_reporter({filename!r}) --> {reporter!r}") if reporter: debug = self.debug.add_label(f"file {filename!r}") reporter = DebugFileReporterWrapper(filename, reporter, debug) return reporter def dynamic_context(self, frame: FrameType) -> Optional[str]: context = self.plugin.dynamic_context(frame) self.debug.write(f"dynamic_context({frame!r}) --> {context!r}") return context def find_executable_files(self, src_dir: str) -> Iterable[str]: executable_files = self.plugin.find_executable_files(src_dir) self.debug.write(f"find_executable_files({src_dir!r}) --> {executable_files!r}") return executable_files def configure(self, config: TConfigurable) -> None: self.debug.write(f"configure({config!r})") self.plugin.configure(config) def sys_info(self) -> Iterable[Tuple[str, Any]]: return self.plugin.sys_info() class DebugFileTracerWrapper(FileTracer): """A debugging `FileTracer`.""" def __init__(self, tracer: FileTracer, debug: LabelledDebug) -> None: self.tracer = tracer self.debug = debug def _show_frame(self, frame: FrameType) -> str: """A short string identifying a frame, for debug messages.""" return "%s@%d" % ( os.path.basename(frame.f_code.co_filename), frame.f_lineno, ) def source_filename(self) -> str: sfilename = self.tracer.source_filename() self.debug.write(f"source_filename() --> {sfilename!r}") return sfilename def has_dynamic_source_filename(self) -> bool: has = self.tracer.has_dynamic_source_filename() self.debug.write(f"has_dynamic_source_filename() --> {has!r}") return has def dynamic_source_filename(self, filename: str, frame: FrameType) -> Optional[str]: dyn = self.tracer.dynamic_source_filename(filename, frame) self.debug.write("dynamic_source_filename({!r}, {}) --> {!r}".format( filename, self._show_frame(frame), dyn, )) return dyn def line_number_range(self, frame: FrameType) -> Tuple[TLineNo, TLineNo]: pair = self.tracer.line_number_range(frame) self.debug.write(f"line_number_range({self._show_frame(frame)}) --> {pair!r}") return pair class DebugFileReporterWrapper(FileReporter): """A debugging `FileReporter`.""" def __init__(self, filename: str, reporter: FileReporter, debug: LabelledDebug) -> None: super().__init__(filename) self.reporter = reporter self.debug = debug def relative_filename(self) -> str: ret = self.reporter.relative_filename() self.debug.write(f"relative_filename() --> {ret!r}") return ret def lines(self) -> Set[TLineNo]: ret = self.reporter.lines() self.debug.write(f"lines() --> {ret!r}") return ret def excluded_lines(self) -> Set[TLineNo]: ret = self.reporter.excluded_lines() self.debug.write(f"excluded_lines() --> {ret!r}") return ret def translate_lines(self, lines: Iterable[TLineNo]) -> Set[TLineNo]: ret = self.reporter.translate_lines(lines) self.debug.write(f"translate_lines({lines!r}) --> {ret!r}") return ret def translate_arcs(self, arcs: Iterable[TArc]) -> Set[TArc]: ret = self.reporter.translate_arcs(arcs) self.debug.write(f"translate_arcs({arcs!r}) --> {ret!r}") return ret def no_branch_lines(self) -> Set[TLineNo]: ret = self.reporter.no_branch_lines() self.debug.write(f"no_branch_lines() --> {ret!r}") return ret def exit_counts(self) -> Dict[TLineNo, int]: ret = self.reporter.exit_counts() self.debug.write(f"exit_counts() --> {ret!r}") return ret def arcs(self) -> Set[TArc]: ret = self.reporter.arcs() self.debug.write(f"arcs() --> {ret!r}") return ret def source(self) -> str: ret = self.reporter.source() self.debug.write("source() --> %d chars" % (len(ret),)) return ret def source_token_lines(self) -> TSourceTokenLines: ret = list(self.reporter.source_token_lines()) self.debug.write("source_token_lines() --> %d tokens" % (len(ret),)) return ret