lsp_server.py

# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License.
"""Implementation of tool support over LSP."""
from __future__ import annotations

import ast
import copy
import json
import os
import pathlib
import sys
import traceback
from typing import Any, Dict, List, Optional, Sequence


# **********************************************************
# Update sys.path before importing any bundled libraries.
# **********************************************************
def update_sys_path(path_to_add: str, strategy: str) -> None:
    """Add given path to `sys.path`."""
    if path_to_add not in sys.path and os.path.isdir(path_to_add):
        if strategy == "useBundled":
            sys.path.insert(0, path_to_add)
        elif strategy == "fromEnvironment":
            sys.path.append(path_to_add)


# Ensure that we can import LSP libraries, and other bundled libraries.
update_sys_path(
    os.fspath(pathlib.Path(__file__).parent.parent / "libs"),
    os.getenv("LS_IMPORT_STRATEGY", "useBundled"),
)

# **********************************************************
# Imports needed for the language server goes below this.
# **********************************************************
# pylint: disable=wrong-import-position,import-error
import isort
import lsp_jsonrpc as jsonrpc
import lsp_utils as utils
import lsprotocol.types as lsp
from pygls import server, uris, workspace

WORKSPACE_SETTINGS = {}
GLOBAL_SETTINGS = {}
RUNNER = pathlib.Path(__file__).parent / "lsp_runner.py"

MAX_WORKERS = 5
LSP_SERVER = server.LanguageServer(
    name="isort-server", version="v0.1.0", max_workers=MAX_WORKERS
)


# **********************************************************
# Tool specific code goes below this.
# **********************************************************
TOOL_MODULE = "isort"
TOOL_DISPLAY = "isort"

# Default arguments always passed to isort.
TOOL_ARGS = []

# Minimum version of isort supported.
MIN_VERSION = "5.10.1"

# **********************************************************
# Linting features start here
# **********************************************************


@LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_OPEN)
def did_open(params: lsp.DidOpenTextDocumentParams) -> None:
    """LSP handler for textDocument/didOpen request."""
    document = LSP_SERVER.workspace.get_document(params.text_document.uri)
    diagnostics: list[lsp.Diagnostic] = _linting_helper(document)
    LSP_SERVER.publish_diagnostics(document.uri, diagnostics)


@LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_SAVE)
def did_save(params: lsp.DidSaveTextDocumentParams) -> None:
    """LSP handler for textDocument/didSave request."""
    document = LSP_SERVER.workspace.get_document(params.text_document.uri)
    diagnostics: list[lsp.Diagnostic] = _linting_helper(document)
    LSP_SERVER.publish_diagnostics(document.uri, diagnostics)


@LSP_SERVER.feature(lsp.TEXT_DOCUMENT_DID_CLOSE)
def did_close(params: lsp.DidCloseTextDocumentParams) -> None:
    """LSP handler for textDocument/didClose request."""
    document = LSP_SERVER.workspace.get_document(params.text_document.uri)
    # Publishing empty diagnostics to clear the entries for this file.
    LSP_SERVER.publish_diagnostics(document.uri, [])


def _linting_helper(document: workspace.Document) -> list[lsp.Diagnostic]:
    # deep copy here to prevent accidentally updating global settings.
    settings = copy.deepcopy(_get_settings_by_document(document))

    if not settings.get("check", False):
        # If sorting check is disabled, return empty diagnostics.
        return []

    try:
        result = _run_tool_on_document(document, use_stdin=True, extra_args=["--check"])
        if result and result.stderr:
            return _parse_output(
                document, result.stderr, severity=settings.get("severity", [])
            )
    except Exception:  # pylint: disable=broad-except
        LSP_SERVER.show_message_log(
            f"isort check failed with error:\r\n{traceback.format_exc()}",
            lsp.MessageType.Error,
        )
    return []


def _get_severity(code_type: str, severity: Dict[str, str]) -> lsp.DiagnosticSeverity:
    """Converts severity provided by isort to LSP specific value."""
    value = severity.get(code_type, "Warning")
    try:
        return lsp.DiagnosticSeverity[value]
    except KeyError:
        pass

    return lsp.DiagnosticSeverity.Warning


def _is_sorting_error(line: str) -> bool:
    return (
        line.startswith("ERROR")
        and line.lower().find("imports are incorrectly sorted") > 0
    )


def _parse_output(
    document: workspace.Document,
    output: str,
    severity: Dict[str, str],
) -> Sequence[lsp.Diagnostic]:
    """Parses isort messages and return LSP diagnostic object for each message."""
    diagnostics = []
    has_error = any(
        [_is_sorting_error(line) for line in output.splitlines(keepends=False)]
    )

    if has_error:
        try:
            import_line = [
                i
                for i, l in enumerate(document.lines)
                if l.startswith("import") or l.startswith("from")
            ][0]
        except IndexError:
            import_line = 0

        diagnostics.append(
            lsp.Diagnostic(
                range=lsp.Range(
                    start=lsp.Position(
                        line=import_line,
                        character=0,
                    ),
                    end=lsp.Position(
                        line=import_line + 1,
                        character=0,
                    ),
                ),
                message="Imports are incorrectly sorted and/or formatted.",
                severity=_get_severity("E", severity),
                code="E",
                source="isort",
            )
        )

    return diagnostics


# **********************************************************
# Linting features end here
# **********************************************************

# **********************************************************
# Code Action features start here
# **********************************************************


@LSP_SERVER.feature(
    lsp.TEXT_DOCUMENT_CODE_ACTION,
    lsp.CodeActionOptions(
        code_action_kinds=[
            lsp.CodeActionKind.SourceOrganizeImports,
            lsp.CodeActionKind.QuickFix,
        ],
        resolve_provider=True,
    ),
)
def code_action_organize_imports(params: lsp.CodeActionParams):
    text_document = LSP_SERVER.workspace.get_document(params.text_document.uri)

    if utils.is_stdlib_file(text_document.path):
        # Don't format standard library python files.
        # Publishing empty diagnostics clears the entry
        return None

    if (
        params.context.only
        and len(params.context.only) == 1
        and lsp.CodeActionKind.SourceOrganizeImports in params.context.only
    ):
        # This is triggered with users run the Organize Imports command from
        # VS Code. The `context.only` field will have one item that is the
        # `SourceOrganizeImports` code action.
        results = _formatting_helper(text_document)
        if results:
            # Clear out diagnostics, since we are making changes to address
            # import sorting issues.
            LSP_SERVER.publish_diagnostics(text_document.uri, [])
            return [
                lsp.CodeAction(
                    title="isort: Organize Imports",
                    kind=lsp.CodeActionKind.SourceOrganizeImports,
                    data=params.text_document.uri,
                    edit=_create_workspace_edits(text_document, results),
                    diagnostics=[],
                )
            ]

    actions = []
    if (
        not params.context.only
        or lsp.CodeActionKind.SourceOrganizeImports in params.context.only
    ):
        actions.append(
            lsp.CodeAction(
                title="isort: Organize Imports",
                kind=lsp.CodeActionKind.SourceOrganizeImports,
                data=params.text_document.uri,
                edit=None,
                diagnostics=[],
            ),
        )

    if not params.context.only or lsp.CodeActionKind.QuickFix in params.context.only:
        diagnostics = [
            d
            for d in params.context.diagnostics
            if d.source == "isort" and d.code == "E"
        ]
        if diagnostics:
            actions.append(
                lsp.CodeAction(
                    title="isort: Fix import sorting and/or formatting",
                    kind=lsp.CodeActionKind.QuickFix,
                    data=params.text_document.uri,
                    edit=None,
                    diagnostics=diagnostics,
                ),
            )

    return actions if actions else None


@LSP_SERVER.feature(lsp.CODE_ACTION_RESOLVE)
def code_action_resolve(params: lsp.CodeAction):
    text_document = LSP_SERVER.workspace.get_document(params.data)

    results = _formatting_helper(text_document)
    if results:
        # Clear out diagnostics, since we are making changes to address
        # import sorting issues.
        LSP_SERVER.publish_diagnostics(text_document.uri, [])
    else:
        # There are no changes so return the original code as is.
        # This could be due to error while running import sorter
        # so, don't clear out the diagnostics.
        results = [
            lsp.TextEdit(
                range=lsp.Range(
                    start=lsp.Position(line=0, character=0),
                    end=lsp.Position(line=len(text_document.lines), character=0),
                ),
                new_text=text_document.source,
            )
        ]

    params.edit = _create_workspace_edits(text_document, results)
    return params


def is_python(code: str) -> bool:
    """Ensures that the code provided is python."""
    try:
        ast.parse(code)
    except SyntaxError:
        log_error(f"Syntax error in code: {traceback.format_exc()}")
        return False
    return True


def is_interactive(file_path: str) -> bool:
    """Checks if the file path represents interactive window."""
    return file_path.endswith(".interactive")


def _formatting_helper(document: workspace.Document) -> list[lsp.TextEdit] | None:
    result = _run_tool_on_document(document, use_stdin=True)
    if result.stdout:
        new_source = _match_line_endings(document, result.stdout)

        # Skip last line ending in a notebook cell
        if document.uri.startswith("vscode-notebook-cell"):
            if new_source.endswith("\r\n"):
                new_source = new_source[:-2]
            elif new_source.endswith("\n"):
                new_source = new_source[:-1]

        if new_source != document.source:
            return [
                lsp.TextEdit(
                    range=lsp.Range(
                        start=lsp.Position(line=0, character=0),
                        end=lsp.Position(line=len(document.lines), character=0),
                    ),
                    new_text=new_source,
                )
            ]
    return None


def _create_workspace_edits(
    document: workspace.Document, results: Optional[List[lsp.TextEdit]]
):
    return lsp.WorkspaceEdit(
        document_changes=[
            lsp.TextDocumentEdit(
                text_document=lsp.VersionedTextDocumentIdentifier(
                    uri=document.uri,
                    version=0 if document.version is None else document.version,
                ),
                edits=results,
            )
        ],
    )


def _get_line_endings(lines: list[str]) -> str:
    """Returns line endings used in the text."""
    try:
        if lines[0][-2:] == "\r\n":
            return "\r\n"
        return "\n"
    except Exception:  # pylint: disable=broad-except
        return None


def _match_line_endings(document: workspace.Document, text: str) -> str:
    """Ensures that the edited text line endings matches the document line endings."""
    expected = _get_line_endings(document.source.splitlines(keepends=True))
    actual = _get_line_endings(text.splitlines(keepends=True))
    if actual == expected or actual is None or expected is None:
        return text
    return text.replace(actual, expected)


# **********************************************************
# Code Action features ends here
# **********************************************************


# **********************************************************
# Required Language Server Initialization and Exit handlers.
# **********************************************************
@LSP_SERVER.feature(lsp.INITIALIZE)
def initialize(params: lsp.InitializeParams) -> None:
    """LSP handler for initialize request."""
    log_to_output(f"CWD Server: {os.getcwd()}")

    paths = "\r\n   ".join(sys.path)
    log_to_output(f"sys.path used to run Server:\r\n   {paths}")

    GLOBAL_SETTINGS.update(**params.initialization_options.get("globalSettings", {}))

    settings = params.initialization_options["settings"]
    _update_workspace_settings(settings)
    log_to_output(
        f"Settings used to run Server:\r\n{json.dumps(settings, indent=4, ensure_ascii=False)}\r\n"
    )
    log_to_output(
        f"Global settings:\r\n{json.dumps(GLOBAL_SETTINGS, indent=4, ensure_ascii=False)}\r\n"
    )

    # Log version and config
    _log_info()


@LSP_SERVER.feature(lsp.EXIT)
def on_exit(_params: Optional[Any] = None):
    """Handle clean up on exit."""
    jsonrpc.shutdown_json_rpc()


@LSP_SERVER.feature(lsp.SHUTDOWN)
def on_shutdown(_params: Optional[Any] = None):
    """Handle clean up on exit."""
    jsonrpc.shutdown_json_rpc()


def _log_info() -> None:
    for settings in WORKSPACE_SETTINGS.values():
        _log_version_info(settings)
        _log_verbose_config(settings)


def _log_version_info(settings: Dict[str, str]) -> None:
    try:
        from packaging.version import parse as parse_version

        settings = copy.deepcopy(settings)
        result = _run_tool(["--version-number"], settings)
        code_workspace = settings["workspaceFS"]

        if result and result.stdout:
            log_to_output(
                f"Version info for isort running for {code_workspace}:\r\n{result.stdout}"
            )
            # This is text we get from running `isort --version-number`
            # 5.10.1
            actual_version = result.stdout.strip()

            version = parse_version(actual_version)
            min_version = parse_version(MIN_VERSION)

            if version < min_version:
                log_error(
                    f"Version of isort running for {code_workspace} is NOT supported:\r\n"
                    f"SUPPORTED {TOOL_MODULE}>={min_version}\r\n"
                    f"FOUND {TOOL_MODULE}=={actual_version}\r\n"
                )
            else:
                log_to_output(
                    f"SUPPORTED {TOOL_MODULE}>={min_version}\r\n"
                    f"FOUND {TOOL_MODULE}=={actual_version}\r\n"
                )
    except:  # pylint: disable=bare-except
        log_to_output(
            f"Error while detecting isort version:\r\n{traceback.format_exc()}"
        )


def _log_verbose_config(settings: Dict[str, str]) -> None:
    if LSP_SERVER.lsp.trace == lsp.TraceValues.Verbose:
        try:
            settings = copy.deepcopy(settings)
            result = _run_tool(["--show-config"], settings)
            code_workspace = settings["workspaceFS"]
            log_to_output(
                f"Config details for isort running for {code_workspace}:\r\n{result.stdout}"
            )
        except:  # pylint: disable=bare-except
            log_to_output(
                f"Error while getting `isort --show-config` config:\r\n{traceback.format_exc()}"
            )


# *****************************************************
# Internal functional and settings management APIs.
# *****************************************************
def _get_global_defaults():
    return {
        "check": GLOBAL_SETTINGS.get("check", False),
        "path": GLOBAL_SETTINGS.get("path", []),
        "severity": GLOBAL_SETTINGS.get("severity", {"E": "Hint", "W": "Warning"}),
        "interpreter": GLOBAL_SETTINGS.get("interpreter", [sys.executable]),
        "args": GLOBAL_SETTINGS.get("args", []),
        "importStrategy": GLOBAL_SETTINGS.get("importStrategy", "useBundled"),
        "showNotifications": GLOBAL_SETTINGS.get("showNotifications", "off"),
    }


def _update_workspace_settings(settings):
    if not settings:
        key = utils.normalize_path(os.getcwd())
        WORKSPACE_SETTINGS[key] = {
            "cwd": key,
            "workspaceFS": key,
            "workspace": uris.from_fs_path(key),
            **_get_global_defaults(),
        }
        return

    for setting in settings:
        key = utils.normalize_path(uris.to_fs_path(setting["workspace"]))
        WORKSPACE_SETTINGS[key] = {
            **setting,
            "workspaceFS": key,
        }


def _get_settings_by_path(file_path: pathlib.Path):
    workspaces = {s["workspaceFS"] for s in WORKSPACE_SETTINGS.values()}

    while file_path != file_path.parent:
        str_file_path = utils.normalize_path(file_path)
        if str_file_path in workspaces:
            return WORKSPACE_SETTINGS[str_file_path]
        file_path = file_path.parent

    setting_values = list(WORKSPACE_SETTINGS.values())
    return setting_values[0]


def _get_document_key(document: workspace.Document):
    if WORKSPACE_SETTINGS:
        document_workspace = pathlib.Path(document.path)
        workspaces = {s["workspaceFS"] for s in WORKSPACE_SETTINGS.values()}

        # Find workspace settings for the given file.
        while document_workspace != document_workspace.parent:
            norm_path = utils.normalize_path(document_workspace)
            if norm_path in workspaces:
                return norm_path
            document_workspace = document_workspace.parent

    return None


def _get_settings_by_document(document: workspace.Document | None):
    if document is None or document.path is None:
        return list(WORKSPACE_SETTINGS.values())[0]

    key = _get_document_key(document)
    if key is None:
        # This is either a non-workspace file or there is no workspace.
        key = utils.normalize_path(pathlib.Path(document.path).parent)
        return {
            "cwd": key,
            "workspaceFS": key,
            "workspace": uris.from_fs_path(key),
            **_get_global_defaults(),
        }

    return WORKSPACE_SETTINGS[str(key)]


# *****************************************************
# Internal execution APIs.
# *****************************************************
# pylint: disable=too-many-branches
def _run_tool_on_document(
    document: workspace.Document,
    use_stdin: bool = False,
    extra_args: Sequence[str] = [],
) -> utils.RunResult | None:
    """Runs tool on the given document.

    if use_stdin is true then contents of the document is passed to the
    tool via stdin.
    """
    if utils.is_stdlib_file(document.path):
        log_warning(f"Skipping standard library file: {document.path}")
        return None

    if is_interactive(document.path):
        log_warning(f"Skipping interactive window: {document.path}")
        return None

    if not is_python(document.source):
        log_warning(f"Skipping non python code: {document.path}")
        return None

    # deep copy here to prevent accidentally updating global settings.
    settings = copy.deepcopy(_get_settings_by_document(document))

    code_workspace = settings["workspaceFS"]
    cwd = settings["workspaceFS"]

    use_path = False
    use_rpc = False
    if settings["path"]:
        # 'path' setting takes priority over everything.
        use_path = True
        argv = settings["path"]
    elif settings["interpreter"] and not utils.is_current_interpreter(
        settings["interpreter"][0]
    ):
        # If there is a different interpreter set use JSON-RPC to the subprocess
        # running under that interpreter.
        argv = [TOOL_MODULE]
        use_rpc = True
    else:
        # if the interpreter is same as the interpreter running this
        # process then run as module.
        argv = [TOOL_MODULE]

    if use_stdin:
        # `isort` requires the first argument to be "-" when using stdin.
        argv += ["-"] + TOOL_ARGS + settings["args"] + extra_args
        argv += ["--filename", document.path]
    else:
        argv += TOOL_ARGS + settings["args"] + extra_args
        argv += [document.path]

    source = document.source.replace("\r\n", "\n")

    argv = [
        os.path.dirname(document.path) if a == "${fileDirname}" else a for a in argv
    ]

    if use_path:
        # This mode is used when running executables.
        log_to_output(" ".join(argv))
        log_to_output(f"CWD Server: {cwd}")
        result = utils.run_path(
            argv=argv,
            use_stdin=use_stdin,
            cwd=cwd,
            source=source,
        )
        if result.stderr:
            log_to_output(result.stderr)
    elif use_rpc:
        # This mode is used if the interpreter running this server is different from
        # the interpreter used for running this server.
        log_to_output(" ".join(settings["interpreter"] + ["-m"] + argv))
        log_to_output(f"CWD Linter: {cwd}")

        result = jsonrpc.run_over_json_rpc(
            workspace=code_workspace,
            interpreter=settings["interpreter"],
            module=TOOL_MODULE,
            argv=argv,
            use_stdin=use_stdin,
            cwd=cwd,
            source=source,
            env={
                "LS_IMPORT_STRATEGY": settings["importStrategy"],
            },
        )
        result = _to_run_result_with_logging(result)
    else:
        # In this mode the tool is run as a module in the same process as the language server.
        log_to_output(" ".join([sys.executable, "-m"] + argv))
        log_to_output(f"CWD Linter: {cwd}")

        try:
            result = utils.run_module(
                module=TOOL_MODULE,
                argv=argv,
                use_stdin=use_stdin,
                cwd=cwd,
                source=source,
            )
        except isort.exceptions.FileSkipped:
            log_warning(traceback.format_exc(chain=True))
            # Ignore file skipped.
        except Exception:
            log_error(traceback.format_exc(chain=True))
            raise
        if result.stderr:
            log_to_output(result.stderr)

    return result


def _run_tool(extra_args: Sequence[str], settings: Dict[str, Any]) -> utils.RunResult:
    """Runs tool."""
    code_workspace = settings["workspaceFS"]
    cwd = settings["workspaceFS"]

    use_path = False
    use_rpc = False
    if len(settings["path"]) > 0:
        # 'path' setting takes priority over everything.
        use_path = True
        argv = settings["path"]
    elif len(settings["interpreter"]) > 0 and not utils.is_current_interpreter(
        settings["interpreter"][0]
    ):
        # If there is a different interpreter set use JSON-RPC to the subprocess
        # running under that interpreter.
        argv = [TOOL_MODULE]
        use_rpc = True
    else:
        # if the interpreter is same as the interpreter running this
        # process then run as module.
        argv = [TOOL_MODULE]

    argv += extra_args

    if use_path:
        # This mode is used when running executables.
        log_to_output(" ".join(argv))
        log_to_output(f"CWD Server: {cwd}")
        result = utils.run_path(argv=argv, use_stdin=True, cwd=cwd)
        if result.stderr:
            log_to_output(result.stderr)
    elif use_rpc:
        # This mode is used if the interpreter running this server is different from
        # the interpreter used for running this server.
        log_to_output(" ".join(settings["interpreter"] + ["-m"] + argv))
        log_to_output(f"CWD Linter: {cwd}")
        result = jsonrpc.run_over_json_rpc(
            workspace=code_workspace,
            interpreter=settings["interpreter"],
            module=TOOL_MODULE,
            argv=argv,
            use_stdin=True,
            cwd=cwd,
            env={
                "LS_IMPORT_STRATEGY": settings["importStrategy"],
            },
        )
        result = _to_run_result_with_logging(result)
    else:
        # In this mode the tool is run as a module in the same process as the language server.
        log_to_output(" ".join([sys.executable, "-m"] + argv))
        log_to_output(f"CWD Linter: {cwd}")
        # This is needed to preserve sys.path, in cases where the tool modifies
        # sys.path and that might not work for this scenario next time around.
        with utils.substitute_attr(sys, "path", [""] + sys.path[:]):
            try:
                result = utils.run_module(
                    module=TOOL_MODULE, argv=argv, use_stdin=True, cwd=cwd
                )
            except Exception:
                log_error(traceback.format_exc(chain=True))
                raise
        if result.stderr:
            log_to_output(result.stderr)

    return result


def _to_run_result_with_logging(rpc_result: jsonrpc.RpcRunResult) -> utils.RunResult:
    error = ""
    if rpc_result.exception:
        log_error(rpc_result.exception)
        error = rpc_result.exception
    elif rpc_result.stderr:
        log_to_output(rpc_result.stderr)
        error = rpc_result.stderr
    return utils.RunResult(rpc_result.stdout, error)


# *****************************************************
# Logging and notification.
# *****************************************************
def log_to_output(
    message: str, msg_type: lsp.MessageType = lsp.MessageType.Log
) -> None:
    """Logs messages to Output > Pylint channel only."""
    LSP_SERVER.show_message_log(message, msg_type)


def log_error(message: str) -> None:
    """Logs messages with notification on error."""
    LSP_SERVER.show_message_log(message, lsp.MessageType.Error)
    if os.getenv("LS_SHOW_NOTIFICATION", "off") in ["onError", "onWarning", "always"]:
        LSP_SERVER.show_message(message, lsp.MessageType.Error)


def log_warning(message: str) -> None:
    """Logs messages with notification on warning."""
    LSP_SERVER.show_message_log(message, lsp.MessageType.Warning)
    if os.getenv("LS_SHOW_NOTIFICATION", "off") in ["onWarning", "always"]:
        LSP_SERVER.show_message(message, lsp.MessageType.Warning)


def log_always(message: str) -> None:
    """Logs messages with notification."""
    LSP_SERVER.show_message_log(message, lsp.MessageType.Info)
    if os.getenv("LS_SHOW_NOTIFICATION", "off") in ["always"]:
        LSP_SERVER.show_message(message, lsp.MessageType.Info)


# *****************************************************
# Start the server.
# *****************************************************
if __name__ == "__main__":
    LSP_SERVER.start_io()