feat: add BSL (1C:Enterprise) language server support

CHANGELOG.md

@@ -24,8 +24,11 @@ Status of the `main` branch. Changes prior to the next official version change w
   - Java (`eclipse.jdt.ls`): Add upstream JDTLS mode for offline / restricted-network use. Setting both `jdtls_path` and `lombok_path` in `ls_specific_settings.java` makes Serena use an existing upstream JDTLS installation (e.g. `brew install jdtls`) and the system JDK 21+, skipping the ~500 MB vscode-java VSIX, Gradle, and IntelliCode downloads. New related setting `java_home` lets the user override the JDK used to launch JDTLS. Default behavior unchanged — the JDTLS workspace hash is preserved bit-for-bit for users on the default route, so existing project caches are reused without a one-time reindex; the launcher path is mixed into the hash only when `jdtls_path` is set, isolating upstream installations from the default workspace. #1415
 
 # v1.2.0 (2026-04-27)
+### Added
+- BSL (1C:Enterprise) language server support via bsl-language-server by 1c-syntax. Supports `.bsl` and `.os` files. Requires Java 11+ on PATH.
 
 * General:
+  - Support `serena --version` CLI command for displaying the current version #1347
   - Fix: Check for ignored path ignored `.git` folder only at the top level, not in every subdirectory (`Project._is_ignored_relative_path`) #1350
   - `GetSymbolsOverviewTool`: ignored paths were not respected in LSP variant (fix in `SolidLanguageServer`)
   - Fix: Duplicate comments in re-saved YAML configuration files #1285
@@ -53,13 +56,6 @@ Status of the `main` branch. Changes prior to the next official version change w
     The `initial_instructions` tool provides the full prompt on demand, keeping the initial context lean.
   - Add `serena_info` tool for on-demand retrieval of usage information
 
-* CLI:
-  - Support `serena --version` CLI command for displaying the current version #1347
-  - Extend `prompts` subcommand with `print-prompt-template` and `print-cc-system-prompt-override`, improve `list` subcommand
-
-* Clients:
-  - Document workaround to make Claude Code use Serena's tools after recent degradations caused by changes in CC harness and Opus 4.7 release.
-
 * JetBrains:
   - Add `debug` tool: The agent can set breakpoints, inspect variables, evaluate expressions and control execution flow
     by directly interacting with the IDE's debugger, using a REPL-style interface for maximum flexibility.  
@@ -84,9 +80,6 @@ Status of the `main` branch. Changes prior to the next official version change w
     Three modes (browser, native app with tray, tray manager for aggregating multiple instances) are supported, depending on the OS
   - Fix: Memory leaks in frontend when using Chromium-based browsers/Windows webview #1389
 
-* Hooks:
-  - Adjusted wording of startup hook, improving project activation instructions #1401.
-
 # v1.1.2 (2026-04-14)
 
 * General:

README.md

@@ -110,7 +110,7 @@ Serena incorporates a powerful abstraction layer for the integration of language
 The underlying language servers are typically open-source projects or at least freely available for use.
 
 When using Serena's language server backend, we provide **support for over 40 programming languages**, including
-AL, Ansible, Bash, C#, C/C++, Clojure, Crystal, Dart, Elixir, Elm, Erlang, Fortran, F#, GLSL, Go, Groovy, Haskell, Haxe, HLSL, Java, JavaScript, JSON, Julia, Kotlin, Lean 4, Lua, Luau, Markdown, MATLAB, mSL, Nix, OCaml, Perl, PHP, PowerShell, Python, R, Ruby, Rust, Scala, Solidity, Swift, TOML, TypeScript, WGSL, YAML, and Zig.
+AL, Ansible, Bash, BSL, C#, C/C++, Clojure, Crystal, Dart, Elixir, Elm, Erlang, Fortran, F#, GLSL, Go, Groovy, Haskell, Haxe, HLSL, Java, JavaScript, JSON, Julia, Kotlin, Lean 4, Lua, Luau, Markdown, MATLAB, mSL, Nix, OCaml, Perl, PHP, PowerShell, Python, R, Ruby, Rust, Scala, Solidity, Swift, TOML, TypeScript, WGSL, YAML, and Zig.
 
 ### The Serena JetBrains Plugin
 

news/bsl-language-server.md

@@ -0,0 +1 @@
+Added support for BSL (1C:Enterprise / OneScript) language via 1c-syntax/bsl-language-server.

pyproject.toml

@@ -349,6 +349,7 @@ markers = [
   "solidity: language server running for Solidity (uses @nomicfoundation/solidity-language-server)",
   "ansible: language server running for Ansible (uses @ansible/ansible-language-server)",
   "msl: language server running for mSL (mIRC Scripting Language)",
+  "bsl: language server running for BSL (1C:Enterprise / OneScript)",
 ]
 
 [tool.codespell]

src/solidlsp/language_servers/bsl_language_server.py

@@ -0,0 +1,138 @@
+"""
+Provides BSL (1C:Enterprise) specific instantiation of the LanguageServer class
+using bsl-language-server by 1c-syntax. Supports .bsl and .os files.
+Requires Java 11+ on PATH.
+"""
+
+import logging
+import os
+import pathlib
+import shutil
+import threading
+
+from solidlsp.language_servers.common import RuntimeDependency, RuntimeDependencyCollection
+from solidlsp.ls import (
+    LanguageServerDependencyProvider,
+    LanguageServerDependencyProviderSinglePath,
+    SolidLanguageServer,
+)
+from solidlsp.ls_config import LanguageServerConfig
+from solidlsp.lsp_protocol_handler.lsp_types import InitializeParams
+from solidlsp.settings import SolidLSPSettings
+
+log = logging.getLogger(__name__)
+
+BSL_LS_VERSION = "0.29.0"
+BSL_LS_JAR_URL = "https://github.com/1c-syntax/bsl-language-server/releases/download/v0.29.0/bsl-language-server-0.29.0-exec.jar"
+BSL_LS_JAR_SHA256 = "d6fa9ad638ba51855e260b88ad1f8ce4e602385845a4ee43600d148f779bcf0b"
+
+
+class BSLLanguageServer(SolidLanguageServer):
+    """
+    BSL (1C:Enterprise / OneScript) language server integration for Serena.
+    """
+
+    def __init__(
+        self,
+        config: LanguageServerConfig,
+        repository_root_path: str,
+        solidlsp_settings: SolidLSPSettings,
+    ):
+        super().__init__(
+            config,
+            repository_root_path,
+            None,
+            "bsl",
+            solidlsp_settings,
+        )
+        self.server_ready = threading.Event()
+
+    def _create_dependency_provider(self) -> LanguageServerDependencyProvider:
+        return self.DependencyProvider(self._custom_settings, self._ls_resources_dir)
+
+    class DependencyProvider(LanguageServerDependencyProviderSinglePath):
+        def _get_or_install_core_dependency(self) -> str:
+            if shutil.which("java") is None:
+                raise RuntimeError("Java 11+ is required for BSL Language Server but was not found on PATH.")
+            jar_dir = os.path.join(self._ls_resources_dir, "bsl-ls")
+            jar_path = os.path.join(jar_dir, "bsl-language-server.jar")
+            if not os.path.exists(jar_path):
+                deps = RuntimeDependencyCollection(
+                    [
+                        RuntimeDependency(
+                            id="bsl-language-server",
+                            description="BSL Language Server JAR by 1c-syntax",
+                            url=BSL_LS_JAR_URL,
+                            sha256=BSL_LS_JAR_SHA256,
+                            archive_type="binary",
+                            binary_name="bsl-language-server.jar",
+                            platform_id="any",
+                        ),
+                    ]
+                )
+                deps.install(jar_dir)
+            if not os.path.exists(jar_path):
+                raise FileNotFoundError(f"BSL Language Server JAR not found at {jar_path} after installation.")
+            return jar_path
+
+        def _create_launch_command(self, core_path: str) -> list[str]:
+            return ["java", "-jar", core_path]
+
+    @staticmethod
+    def _get_initialize_params(repository_absolute_path: str) -> InitializeParams:
+        root_uri = pathlib.Path(repository_absolute_path).as_uri()
+        return {  # type: ignore[return-value]
+            "locale": "en",
+            "capabilities": {
+                "textDocument": {
+                    "synchronization": {"didSave": True, "dynamicRegistration": True},
+                    "definition": {"dynamicRegistration": True},
+                    "references": {"dynamicRegistration": True},
+                    "documentSymbol": {
+                        "dynamicRegistration": True,
+                        "hierarchicalDocumentSymbolSupport": True,
+                        "symbolKind": {"valueSet": list(range(1, 27))},  # type: ignore
+                    },
+                    "hover": {"dynamicRegistration": True, "contentFormat": ["markdown", "plaintext"]},  # type: ignore
+                    "rename": {"dynamicRegistration": True, "prepareSupport": True},
+                },
+                "workspace": {
+                    "workspaceFolders": True,
+                    "didChangeConfiguration": {"dynamicRegistration": True},
+                    "symbol": {"dynamicRegistration": True},
+                },
+            },
+            "processId": os.getpid(),
+            "rootPath": repository_absolute_path,
+            "rootUri": root_uri,
+            "workspaceFolders": [
+                {"uri": root_uri, "name": os.path.basename(repository_absolute_path)},
+            ],
+        }
+
+    def _start_server(self) -> None:
+        def window_log_message(msg: dict) -> None:
+            log.info("BSL LSP: %s", msg.get("message", ""))
+
+        def do_nothing(_: dict) -> None:
+            return
+
+        self.server.on_notification("window/logMessage", window_log_message)
+        self.server.on_notification("$/progress", do_nothing)
+        self.server.on_notification("textDocument/publishDiagnostics", do_nothing)
+        self.server.on_request(
+            "client/registerCapability",
+            lambda params: None,
+        )
+
+        log.info("Starting BSL language server process")
+        self.server.start()
+
+        init_params = self._get_initialize_params(self.repository_root_path)
+        init_response = self.server.send.initialize(init_params)
+        log.debug("BSL LSP initialize response: %s", init_response)
+
+        assert "capabilities" in init_response, "BSL LSP did not return capabilities"
+
+        self.server.notify.initialized({})
+        self.server_ready.set()

src/solidlsp/ls_config.py

@@ -94,6 +94,11 @@ class Language(str, Enum):
     Uses a custom LSP server based on pygls. Automatically sets up
     a virtual environment with pygls dependencies on first use.
     """
+    BSL = "bsl"
+    """BSL Language Server for 1C:Enterprise and OneScript languages.
+    Uses bsl-language-server by 1c-syntax. Automatically downloads the JAR.
+    Supports .bsl and .os files. Requires Java 11+ on PATH.
+    """
     # Experimental or deprecated Language Servers
     TYPESCRIPT_VTS = "typescript_vts"
     """Use the typescript language server through the natively bundled vscode extension via https://github.com/yioneko/vtsls"""
@@ -344,6 +349,8 @@ def get_source_fn_matcher(self) -> FilenameMatcher:
                 return FilenameMatcher("*.yaml", "*.yml")
             case self.MSL:
                 return FilenameMatcher("*.mrc")
+            case self.BSL:
+                return FilenameMatcher("*.bsl", "*.os")
             case _:
                 raise ValueError(f"Unhandled language: {self}")
 
@@ -378,7 +385,7 @@ def get_ls_class(self) -> type["SolidLanguageServer"]:
 
                 return CSharpLanguageServer
             case self.CSHARP_OMNISHARP:
-                from solidlsp.language_servers.omnisharp import OmniSharp
+                from solidlsp.language_servers.omnisharp import OmniSharp  # type: ignore[attr-defined]
 
                 return OmniSharp
             case self.TYPESCRIPT:
@@ -575,6 +582,10 @@ def get_ls_class(self) -> type["SolidLanguageServer"]:
                 from solidlsp.language_servers.msl_language_server import MslLanguageServer
 
                 return MslLanguageServer
+            case self.BSL:
+                from solidlsp.language_servers.bsl_language_server import BSLLanguageServer
+
+                return BSLLanguageServer
             case _:
                 raise ValueError(f"Unhandled language: {self}")
 

test/conftest.py

@@ -272,6 +272,10 @@ def project_with_ls(request: LanguageParamRequest) -> Iterator[Project]:
     Language.PYTHON_TY: [pytest.mark.python],
     Language.RUST: [pytest.mark.rust],
     Language.TYPESCRIPT: [pytest.mark.typescript],
+    Language.BSL: [
+        pytest.mark.bsl,
+        pytest.mark.skipif(_sh.which("java") is None, reason="Java is not installed"),
+    ],
 }
 
 
@@ -319,6 +323,10 @@ def _determine_disabled_languages() -> list[Language]:
     if not al_tests_enabled:
         result.append(Language.AL)
 
+    # Disable BSL tests in CI or when Java is not available
+    if is_ci or _sh.which("java") is None:
+        result.append(Language.BSL)
+
     return result
 
 

test/resources/repos/bsl/test_repo/.bsl-language-server.json

@@ -0,0 +1,5 @@
+{
+  "language": "ru",
+  "diagnosticLanguage": "ru",
+  "computeDiagnostics": "onSave"
+}

test/resources/repos/bsl/test_repo/CommonModule.bsl

@@ -0,0 +1,14 @@
+// CommonModule.bsl - common module with reusable procedures
+
+Процедура ВывестиСообщение(Текст) Экспорт
+    Сообщить(Текст);
+КонецПроцедуры
+
+Функция ПолучитьПриветствие(Имя) Экспорт
+    Возврат "Привет, " + Имя + "!";
+КонецФункции
+
+Процедура ВызватьПриветствие() Экспорт
+    Сообщение = ПолучитьПриветствие("Мир");
+    ВывестиСообщение(Сообщение);
+КонецПроцедуры

test/resources/repos/bsl/test_repo/ObjectModule.bsl

@@ -0,0 +1,11 @@
+// ObjectModule.bsl - object module example
+
+Перем ВнутреннееСостояние;
+
+Процедура Инициализировать() Экспорт
+    ВнутреннееСостояние = "ready";
+КонецПроцедуры
+
+Функция ПолучитьСостояние() Экспорт
+    Возврат ВнутреннееСостояние;
+КонецФункции