lsp.py: Port to support running on Windows & adapt to changes due to prior merged PR.

- lsp.py: Fixes invalid-syntax by Python interpreter on Windows CI (older Python version).
- lsp.py: Savely strip CRLF from right side of the string, ignoring accidental multiple occurrences of \r (such as \r\r\n).
- lsp.py: Fixes reading single character from stdin (wrt. Windows platform).
- lsp.py: Adds header line reading to I/O tracing (useful for debugging).
- lsp.py: When running the tests on Windows, don't care test file content's newlines but simply expect LFs (instead of CRLF for example).
- Apply pylint notes.
- Fixing use of @functools.lru_cache for older python versions (CircleCI Windows)

.circleci/config.yml

@@ -1283,6 +1283,9 @@ jobs:
       - run:
           name: Install LSP test dependencies
           command: python -m pip install --user deepdiff colorama
+      - run:
+          name: Inspect lsp.py
+          command: Get-Content ./test/lsp.py
       - run:
           name: Executing solc LSP test suite
           command: python ./test/lsp.py .\build\solc\Release\solc.exe

test/lsp.py

@@ -1,26 +1,57 @@
 #!/usr/bin/env python3
 # pragma pylint: disable=too-many-lines
+# test line 1
 import argparse
 import fnmatch
+import functools
 import json
 import os
+import re
 import subprocess
 import sys
 import traceback
-import re
-import tty
-import functools
 from collections import namedtuple
 from copy import deepcopy
+from enum import Enum, auto
+from itertools import islice
 from pathlib import PurePath
 from typing import Any, List, Optional, Tuple, Union
-from itertools import islice
 
-from enum import Enum, auto
-
-import colorama # Enables the use of SGR & CUP terminal VT sequences on Windows.
+import colorama  # Enables the use of SGR & CUP terminal VT sequences on Windows.
 from deepdiff import DeepDiff
 
+if os.name == 'nt':
+    # pragma pylint: disable=import-error
+    import msvcrt
+else:
+    import tty
+    # Turn off user input buffering so we get the input immediately,
+    # not only after a line break
+    tty.setcbreak(sys.stdin.fileno())
+
+
+def escape_string(text: str) -> str:
+    """
+    Trivially escapes given input string's \r \n and \\.
+    """
+    return text.translate(str.maketrans({
+        "\r": r"\r",
+        "\n": r"\n",
+        "\\": r"\\"
+    }))
+
+
+def getCharFromStdin():
+    """
+    Gets a single character from stdin without line-buffering.
+    """
+    if os.name == 'nt':
+        # pragma pylint: disable=import-error
+        return msvcrt.getch().decode("utf-8")
+    else:
+        return sys.stdin.buffer.read(1)
+
+
 """
 Named tuple that holds various regexes used to parse the test specification.
 """
@@ -101,7 +132,6 @@ class BadHeader(Exception):
     def __init__(self, msg: str):
         super().__init__("Bad header: " + msg)
 
-
 class JsonRpcProcess:
     exe_path: str
     exe_args: List[str]
@@ -144,10 +174,12 @@ class JsonRpcProcess:
                 # server quit
                 return None
             line = line.decode("utf-8")
+            if self.trace_io:
+                print(f"Received header-line: {escape_string(line)}")
             if not line.endswith("\r\n"):
                 raise BadHeader("missing newline")
-            # remove the "\r\n"
-            line = line[:-2]
+            # Safely remove the "\r\n".
+            line = line.rstrip("\r\n")
             if line == '':
                 break # done with the headers
             if line.startswith(CONTENT_LENGTH_HEADER):
@@ -589,7 +621,7 @@ class FileTestRunner:
 
         while True:
             print("(u)pdate/(r)etry/(i)gnore?")
-            user_response = sys.stdin.read(1)
+            user_response = getCharFromStdin()
             if user_response == "i":
                 return self.TestResult.SuccessOrIgnored
 
@@ -787,7 +819,7 @@ class SolidityLSPTestSuite: # {{{
         in the test path (test/libsolidity/lsp).
         """
         with open(self.get_test_file_path(test_case_name), mode="r", encoding="utf-8", newline='') as f:
-            return f.read()
+            return f.read().replace("\r\n", "\n")
 
     def require_params_for_method(self, method_name: str, message: dict) -> Any:
         """
@@ -1059,7 +1091,7 @@ class SolidityLSPTestSuite: # {{{
         """
         while True:
             print("(u)pdate/(r)etry/(s)kip file?")
-            user_response = sys.stdin.read(1)
+            user_response = getCharFromStdin()
             if user_response == "u":
                 while True:
                     try:
@@ -1068,8 +1100,8 @@ class SolidityLSPTestSuite: # {{{
                     # pragma pylint: disable=broad-except
                     except Exception as e:
                         print(e)
-                        if ret := self.user_interaction_failed_autoupdate(test):
-                            return ret
+                        if self.user_interaction_failed_autoupdate(test):
+                            return True
             elif user_response == 's':
                 return True
             elif user_response == 'r':
@@ -1077,7 +1109,7 @@ class SolidityLSPTestSuite: # {{{
 
     def user_interaction_failed_autoupdate(self, test):
         print("(e)dit/(r)etry/(s)kip file?")
-        user_response = sys.stdin.read(1)
+        user_response = getCharFromStdin()
         if user_response == "r":
             print("retrying...")
             # pragma pylint: disable=no-member
@@ -1142,7 +1174,7 @@ class SolidityLSPTestSuite: # {{{
         marker = self.get_file_tags("lib")["@diagnostics"]
         self.expect_diagnostic(report['diagnostics'][0], code=2072, marker=marker)
 
-    @functools.lru_cache # pragma pylint: disable=lru-cache-decorating-method
+    @functools.lru_cache() # pragma pylint: disable=lru-cache-decorating-method
     def get_file_tags(self, test_name: str, verbose=False):
         """
         Finds all tags (e.g. @tagname) in the given test and returns them as a
@@ -1653,10 +1685,8 @@ class SolidityLSPTestSuite: # {{{
     # }}}
     # }}}
 
+
 if __name__ == "__main__":
-    # Turn off user input buffering so we get the input immediately,
-    # not only after a line break
-    tty.setcbreak(sys.stdin.fileno())
     suite = SolidityLSPTestSuite()
     exit_code = suite.main()
     sys.exit(exit_code)