fix(analyze): ignore intentionally unused variables in CLI diagnostics

Treat variable names starting with "_" as intentionally unused in CLI unused-variable diagnostics, matching the language server behavior.

Closes #593

Author: d-biehl

packages/analyze/src/robotcode/analyze/code/robot_framework_language_provider.py

@@ -13,6 +13,7 @@
 from robotcode.core.text_document import TextDocument
 from robotcode.core.uri import Uri
 from robotcode.core.workspace import WorkspaceFolder
+from robotcode.robot.diagnostics.diagnostic_rules import is_variable_name_intentionally_unused
 from robotcode.robot.diagnostics.document_cache_helper import DocumentsCacheHelper
 from robotcode.robot.diagnostics.entities import (
     ArgumentDefinition,
@@ -165,6 +166,9 @@ def collect_unused_variables(self, sender: Any, document: TextDocument) -> Optio
             ):
                 continue
 
+            if is_variable_name_intentionally_unused(var):
+                continue
+
             if var.source != namespace.source:
                 continue
 

packages/language_server/src/robotcode/language_server/robotframework/parts/diagnostics.py

@@ -13,6 +13,7 @@
 from robotcode.core.text_document import TextDocument
 from robotcode.core.utils.logging import LoggingDescriptor
 from robotcode.language_server.robotframework.configuration import AnalysisConfig
+from robotcode.robot.diagnostics.diagnostic_rules import is_variable_name_intentionally_unused
 from robotcode.robot.diagnostics.entities import (
     ArgumentDefinition,
     EnvironmentVariableDefinition,
@@ -235,7 +236,7 @@ def _collect_unused_variable_references(self, document: TextDocument) -> Diagnos
                 ):
                     continue
 
-                if var.name_token is not None and var.name_token.value and var.name_token.value.startswith("_"):
+                if is_variable_name_intentionally_unused(var):
                     continue
 
                 references = self.parent.robot_references.find_variable_references(document, var, False, True)

packages/robot/src/robotcode/robot/diagnostics/diagnostic_rules.py

@@ -0,0 +1,12 @@
+"""Shared diagnostic rule helpers."""
+
+from .entities import VariableDefinition
+
+
+def is_variable_name_intentionally_unused(variable: VariableDefinition) -> bool:
+    """Return whether a variable follows the intentionally unused naming convention."""
+    return (
+        variable.name_token is not None
+        and bool(variable.name_token.value)
+        and variable.name_token.value.startswith("_")
+    )

tests/robotcode/robot/diagnostics/test_unused_variable_diagnostics.py

@@ -0,0 +1,51 @@
+from types import SimpleNamespace
+from typing import Any, cast
+
+from pytest_mock import MockerFixture
+from robot.parsing.lexer.tokens import Token
+
+from robotcode.analyze.code.robot_framework_language_provider import RobotFrameworkLanguageProvider
+from robotcode.core.lsp.types import Diagnostic
+from robotcode.robot.diagnostics.entities import LocalVariableDefinition
+from robotcode.robot.diagnostics.namespace import DocumentType
+
+SOURCE = "/suite.robot"
+
+
+def _local_variable(name_base: str, line_no: int) -> LocalVariableDefinition:
+    name_token = Token(Token.VARIABLE, name_base, line_no, 0)
+    return LocalVariableDefinition(
+        name=f"${{{name_base}}}",
+        name_token=name_token,
+        line_no=line_no,
+        col_offset=0,
+        end_line_no=line_no,
+        end_col_offset=len(name_base),
+        source=SOURCE,
+    )
+
+
+def test_cli_unused_variable_diagnostics_ignore_intentionally_unused_variables(mocker: MockerFixture) -> None:
+    intentionally_unused = _local_variable("_", 1)
+    prefixed_intentionally_unused = _local_variable("_ignored", 2)
+    unused = _local_variable("unused", 3)
+
+    variable_references: dict[LocalVariableDefinition, set[Any]] = {
+        intentionally_unused: set(),
+        prefixed_intentionally_unused: set(),
+        unused: set(),
+    }
+    namespace = SimpleNamespace(source=SOURCE, variable_references=variable_references)
+    document_cache = mocker.Mock()
+    document_cache.get_namespace.return_value = namespace
+    document_cache.get_project_index.return_value = mocker.Mock()
+    document_cache.get_document_type.return_value = DocumentType.GENERAL
+
+    provider = cast(Any, object.__new__(RobotFrameworkLanguageProvider))
+    provider.diagnostics_context = SimpleNamespace(collect_unused=True)
+    provider._document_cache = document_cache
+
+    diagnostics = cast(list[Diagnostic], provider.collect_unused_variables(mocker.Mock(), mocker.Mock()))
+
+    assert [diagnostic.message for diagnostic in diagnostics] == ["Variable '${unused}' is not used."]
+    assert [diagnostic.code for diagnostic in diagnostics] == ["VariableNotUsed"]