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# 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
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