Merge pull request #277 from cs50/develop

v3.0

help50/__init__.py

@@ -0,0 +1,45 @@
+
+from pkg_resources import get_distribution, DistributionNotFound
+import os
+
+# https://stackoverflow.com/questions/17583443/what-is-the-correct-way-to-share-package-version-with-setup-py-and-the-package
+try:
+    _dist = get_distribution("help50")
+    # Normalize path for cross-OS compatibility.
+    _dist_loc = os.path.normcase(_dist.location)
+    _here = os.path.normcase(__file__)
+    if not _here.startswith(os.path.join(_dist_loc, "help50")):
+        # This version is not installed, but another version is.
+        raise DistributionNotFound
+except DistributionNotFound:
+    __version__ = "locally installed, no version information available"
+else:
+    __version__ = _dist.version
+
+
+import collections
+
+HELPERS = collections.defaultdict(list)
+PREPROCESSORS = collections.defaultdict(list)
+
+
+def helper(*domains):
+    """ Decorator that indicateas that a given function is a helper. """
+    def decorator(func):
+        for domain in domains:
+            HELPERS[domain].append(func)
+        return func
+    return decorator
+
+
+def preprocessor(*domains):
+    """ Decorator that indicateas that a given function is a preprocessor. """
+    def decorator(func):
+        for domain in domains:
+            PREPROCESSORS[domain].append(func)
+        return func
+    return decorator
+
+
+class Error(Exception):
+    pass

help50/__main__.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python
+import io
+import os
+import re
+import shlex
+import sys
+import tempfile
+import traceback
+
+from argparse import ArgumentParser, REMAINDER
+import lib50
+import termcolor
+import pexpect
+
+from . import __version__, internal, Error
+
+
+def excepthook(cls, exc, tb):
+    if (issubclass(cls, lib50.Error) or issubclass(cls, Error)) and exc.args:
+        termcolor.cprint(str(exc), "red", file=sys.stderr)
+    elif issubclass(cls, FileNotFoundError):
+        termcolor.cprint(f"{exc.filename} not found", "red", file=sys.stderr)
+    elif issubclass(cls, KeyboardInterrupt):
+        print()
+    elif not issubclass(cls, Exception):
+        return
+    else:
+        termcolor.cprint("Sorry, something's wrong! Let [email protected] know!", "red", file=sys.stderr)
+
+    if excepthook.verbose:
+        traceback.print_exception(cls, exc, tb)
+
+    sys.exit(1)
+
+
+excepthook.verbose = True
+sys.excepthook = excepthook
+
+
+def render_help(help):
+    """
+    Display help message to student.
+
+    `help` should be a 2-tuple whose first element is the part of the error
+    message that is being translated and whose second element is the
+    translation itself.
+    """
+    if help is None:
+        termcolor.cprint("Sorry, help50 does not yet know how to help with this!", "yellow")
+    else:
+        for line in help[0]:
+            termcolor.cprint(line, "grey", "on_yellow")
+        print()
+        termcolor.cprint(re.sub(r"`([^`]+)`", r"\033[1m\1\033[22m", " " .join(help[1])), "yellow")
+
+
+def main():
+    parser = ArgumentParser(prog="help50",
+                            description="A command-line tool that helps "
+                                        "students understand error messages.")
+    parser.add_argument("-s", "--slug", help="identifier indicating from where to download helpers", default="cs50/helpers/master")
+    parser.add_argument("-d", "--dev", help="slug will be treated as a local path, useful for developing helpers (implies --verbose)", action="store_true")
+    parser.add_argument("-i", "--interactive", help="read command output from stdin instead of running a command", action="store_true")
+    parser.add_argument("-v", "--verbose", help="display the full tracebacks of any errors", action="store_true")
+    parser.add_argument("-V", "--version", action="version", version=f"%(prog)s {__version__}")
+    parser.add_argument("command", nargs=REMAINDER,
+                        default=[], help="command to be run")
+    args = parser.parse_args()
+
+    if args.dev:
+        args.verbose = True
+
+    excepthook.verbose = args.verbose
+
+
+    if args.interactive:
+        script = sys.stdin.read()
+    elif args.command:
+        # Capture stdout and stderr from process, and print it out
+        with tempfile.TemporaryFile(mode="r+b") as temp:
+            env = os.environ.copy()
+            # Hack to prevent some programs from wrapping their error messages
+            env["COLUMNS"] = "5050"
+            proc = pexpect.spawn(f"bash -lc \"{' '.join(shlex.quote(word) for word in args.command)}\"", env=env)
+            proc.logfile_read = temp
+            proc.interact()
+            proc.close()
+
+            temp.seek(0)
+            script = temp.read().decode().replace("\r\n", "\n")
+    else:
+        raise Error("Careful, you forgot to tell me with which command you "
+                    "need help!")
+    termcolor.cprint("\nAsking for help...\n", "yellow")
+
+    try:
+        helpers_dir = args.slug if args.dev else lib50.local(args.slug)
+    except lib50.Error:
+        raise Error("Failed to fetch helpers, please ensure that you are connected to the internet!")
+
+    internal.load_helpers(helpers_dir)
+    render_help(internal.get_help(script))
+
+
+if __name__ == "__main__":
+    main()

help50/internal.py

@@ -0,0 +1,79 @@
+import contextlib
+import os
+import re
+import sys
+
+import lib50
+
+from . import HELPERS, PREPROCESSORS
+
+lib50.set_local_path(os.environ.get("HELP50_PATH", "~/.local/share/help50"))
+CONFIG_LOADER = lib50.config.Loader("help50")
+
+
+@contextlib.contextmanager
+def _syspath(newpath):
+    """ Useful contextmanager that temporarily replaces sys.path. """
+    oldpath = sys.path
+    sys.path = newpath
+    try:
+        yield
+    finally:
+        sys.path = oldpath
+
+
+def load_config(dir):
+    """ Read cs50 YAML file and apply default configuration to unspecified fields.  """
+    options = { "helpers": ["helpers"] }
+    try:
+        config_file = lib50.config.get_config_filepath(dir)
+
+        with open(config_file) as f:
+            config = CONFIG_LOADER.load(f.read())
+    except lib50.InvalidConfigError:
+        raise Error("Failed to parse help50 config, please let [email protected] know!")
+
+
+    if isinstance(config, dict):
+        options.update(config)
+
+    if isinstance(options["helpers"], str):
+        options["helpers"] = [options["helpers"]]
+
+    return options
+
+
+def load_helpers(helpers_dir):
+    """ Download helpers to a local directory via lib50. """
+
+    config = load_config(helpers_dir)
+    for helper in config["helpers"]:
+        with _syspath([str(helpers_dir)]):
+            try:
+                __import__(helper)
+            except ImportError:
+                raise Error("Failed to load helpers, please let [email protected] know!")
+
+
+def get_help(output):
+    """
+    Given an error message, try every helper registered with help50 and return the output of the
+    first one that matches.
+    """
+    # Strip ANSI codes
+    output = re.sub(r"\x1B\[[0-?]*[ -/]*[@-~]", "", output)
+
+    for domain in HELPERS.keys():
+        processed = output
+        for pre in PREPROCESSORS.get(domain, []):
+            processed = pre(processed)
+        lines = processed.splitlines()
+        for i in range(len(lines)):
+            slice = lines[i:]
+            for helper in HELPERS.get(domain, []):
+                try:
+                    before, after = helper(slice)
+                except TypeError:
+                    pass
+                else:
+                    return before, after

setup.py

@@ -12,11 +12,14 @@
     ],
     license="GPLv3",
     description="This is help50, a command-line tool that helps students understand error messages.",
-    install_requires=["argparse", "requests", "pexpect", "termcolor"],
+    install_requires=["pexpect", "termcolor", "lib50>=1.1.10"],
     keywords="help50",
     name="help50",
-    scripts=["help50"],
+    packages=["help50"],
+    entry_points={
+        "console_scripts": ["help50=help50.__main__:main"]
+    },
     py_requires="3.6",
     url="https://github.com/cs50/help50",
-    version="2.0.1"
+    version="3.0.0"
 )