Fix: Compensate for incorrect body end coordinates in Godot LS (#1974)

Godot's GDScript parser can report a symbol's end column one column past the
line-end convention every other language server follows (closing a node's range from
the next lookahead token instead of the last consumed one, when that lookahead is a
synthesized newline); `replace_symbol_body` on the last function in a file silently
consumed the separating blank line as a result. `GodotLanguageServer` now corrects this
specific, measured overshoot when building its high-level document symbols (#1974)

---------

Signed-off-by: Amir Fathi <amirfathi.me@gmail.com>

test/solidlsp/util/test_godot_symbol_fix.py

@@ -0,0 +1,80 @@
+"""Unit tests for GodotLanguageServer's document-symbol range correction.
+
+See oraios/serena#1974: Godot's GDScript parser can report a symbol's end column one
+column past the line-end convention every other language server follows, which silently
+rolls over into the following line's content (or, at the last line of a body, into the
+separating blank line) when the position is later turned into a text index.
+"""
+
+from __future__ import annotations
+
+from solidlsp.language_servers.godot_language_server import GodotLanguageServer
+
+_fix_range_end = GodotLanguageServer._fix_range_end
+_fix_symbol_ranges = GodotLanguageServer._fix_symbol_ranges
+
+
+def _range(end_line: int, end_char: int, start_line: int = 0, start_char: int = 0) -> dict:
+    return {"start": {"line": start_line, "character": start_char}, "end": {"line": end_line, "character": end_char}}
+
+
+# The exact fixture from the reported issue: a 13-char line whose reported end column is 14.
+_ISSUE_1952_LINES = ["extends Node", "", "func first():", '\tprint("old")', "", "func second():", '\tprint("keep")']
+
+
+def test_fix_range_end_corrects_the_measured_off_by_one() -> None:
+    rng = _range(end_line=3, end_char=14)
+    _fix_range_end(rng, _ISSUE_1952_LINES)
+    assert rng["end"]["character"] == 13
+
+
+def test_fix_range_end_leaves_a_correct_one_past_end_column_alone() -> None:
+    rng = _range(end_line=3, end_char=13)
+    _fix_range_end(rng, _ISSUE_1952_LINES)
+    assert rng["end"]["character"] == 13
+
+
+def test_fix_range_end_does_not_guess_at_a_larger_overshoot() -> None:
+    # Two past the line's end is not the measured Godot mechanism; leave it as reported
+    # rather than assume the same +1 correction applies.
+    rng = _range(end_line=3, end_char=15)
+    _fix_range_end(rng, _ISSUE_1952_LINES)
+    assert rng["end"]["character"] == 15
+
+
+def test_fix_range_end_ignores_an_out_of_range_line() -> None:
+    rng = _range(end_line=99, end_char=5)
+    _fix_range_end(rng, _ISSUE_1952_LINES)
+    assert rng["end"]["character"] == 5
+
+
+def test_fix_range_end_tolerates_a_missing_end() -> None:
+    _fix_range_end({"start": {"line": 0, "character": 0}}, _ISSUE_1952_LINES)  # must not raise
+
+
+def test_fix_symbol_ranges_corrects_range_selection_range_and_location_recursively() -> None:
+    # line 2, "func first():", is 13 chars: end_char=14 is the off-by-one, end_char=5 is not.
+    child = {
+        "name": "inner",
+        "range": _range(end_line=3, end_char=14),
+        "selectionRange": _range(end_line=2, end_char=14, start_line=2),
+    }
+    root = {
+        "name": "first",
+        "range": _range(end_line=3, end_char=14),
+        "selectionRange": _range(end_line=2, end_char=5, start_line=2),
+        "children": [child],
+    }
+    _fix_symbol_ranges(root, _ISSUE_1952_LINES)
+
+    assert root["range"]["end"]["character"] == 13
+    assert root["selectionRange"]["end"]["character"] == 5  # unaffected, no overshoot
+    assert child["range"]["end"]["character"] == 13
+    assert child["selectionRange"]["end"]["character"] == 13  # line 2 is 13 chars, 14 was the overshoot
+
+
+def test_fix_symbol_ranges_corrects_symbol_information_style_location() -> None:
+    # SymbolInformation (the flat, non-hierarchical shape) nests its range under "location".
+    symbol = {"name": "first", "location": {"uri": "file:///script.gd", "range": _range(end_line=3, end_char=14)}}
+    _fix_symbol_ranges(symbol, _ISSUE_1952_LINES)
+    assert symbol["location"]["range"]["end"]["character"] == 13