Support ls_args and ls_extra_args centrally in LanguageServerDependencyProviderBaseCommand

* ls_args overrides the internal command builder, fully defining the arguments
* ls_extra_args appends additional arguments to the launch command

CHANGELOG.md

@@ -59,6 +59,7 @@ Status of the `main` branch. Changes prior to the next official version change w
   - Improve quoting of arguments in shell executions
   - Add **LaTeX** support (experimental) via [texlab](https://github.com/latex-lsp/texlab).
   - PHP: add support for PHPantom as alternative to the already supported PHP LS #1554.
+  - Add new launch command customization options: `ls_args`, `ls_extra_args`
 
 * JetBrains:
   - Add configuration option `jetbrains_launch_command`, allowing Serena to spawn IDE instances automatically

docs/02-usage/050_configuration.md

@@ -216,31 +216,39 @@ ls_specific_settings:
 ```
 
 (override-ls-path)=
-#### Overriding the Language Server Path
+#### Customizing the Language Server Launch Command
 
-Most of Serena's language servers, particularly those that use a single core path for the language server (e.g. the main executable),
-support overriding that path via the `ls_path` setting.
-Therefore, if you have installed the language server yourself and want to use your installation 
-instead of Serena's managed installation, you can set the `ls_path` setting as follows:
+Most of Serena's language servers construct the command that launches the language server process from
+a *base command* or a *core dependency*.
+For these language servers, the following settings can be used to customize the launch command:
+
+| Setting                | Description                                                                                                                                                                                                                               |
+|------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `ls_path` (string)     | overrides the path of the language server's core dependency (e.g. its executable or a JAR file). Use this if you have installed the language server yourself and want Serena to use your installation instead of its managed installation. |
+| `ls_args` (list)       | overrides the internal command construction completely and simply adds `ls_args` to the base command                                                                                                                                      | 
+| `ls_extra_args` (list) | a list of additional arguments to append to the launch command                                                                                                                                                                            |
+
+* If you set `ls_args`, the internal command construction (which may do more than to append arguments to a base command) is bypassed.
+  You can define the full launch command by providing both `ls_path` and `ls_args`.
+* If `ls_args` is not set, the internal command construction (which sets default arguments) is applied, and you can use `ls_path` to override the path of the core dependency.
+* `ls_extra_args` is always appended to the end of the launch command.
+
+Example:
 
 ```yaml
 ls_specific_settings:
   <language>:
     ls_path: "/path/to/language-server"
+    ls_extra_args: ["--log-level=debug"]
 ```
 
-This is supported by all language servers deriving their dependency provider from `LanguageServerDependencyProviderSinglePath`,
-and by some additional wrappers that explicitly expose `ls_path`.
+These settings are supported by all language servers whose dependency provider derives from
+`LanguageServerDependencyProviderBaseCommand`, and `ls_path` is additionally exposed by some wrappers explicitly.
 Common examples include: `ansible`, `bash`, `bsl`, `clojure`, `cpp`, `cpp_ccls`, `hlsl`, `html`, `kotlin`, `lean4`, `luau`, `markdown`, `php`,
 `php_phpactor`, `python`, `rust`, `scss`, `solidity`, `systemverilog`, `toml`, `typescript`, and `yaml`.
 
-Note: `angular` does **not** support `ls_path` — the Angular language server is part of a multi-process orchestration
-(`ngserver` plus a companion TypeScript language server with the `@angular/language-service` plugin and an HTML
-companion) where the dependency layout matters; use the version overrides documented in the Angular section below
-to pin specific releases of the bundled stack.
-
-If a language server supports `ls_path`, setting it bypasses Serena's managed download or install for that server.
-In that case, any server-specific version or registry settings only apply when `ls_path` is not set.
+If `ls_path` is set, Serena's managed download or install is bypassed for that language server.
+In that case, any server-specific version or registry settings do not apply.
 
 #### AL
 

src/solidlsp/ls.py

@@ -301,8 +301,14 @@ class LanguageServerDependencyProvider(ABC):
 
 class LanguageServerDependencyProviderBaseCommand(LanguageServerDependencyProvider, ABC):
     """
-    Special case of a dependency provider, where the launch command is constructed from a base command
-    (which can potentially be overridden by the user in LS-specific settings).
+    Special case of a dependency provider, where the launch command is constructed from a base command.
+
+    The user can configure aspects of the launch command in LS-specific settings:
+
+      * ``ls_path``: overrides the path of the language server's core dependency (e.g. its executable or a JAR file),
+        from which the base command is formed, bypassing Serena's managed installation
+      * ``ls_args``: overrides the arguments that are added to the base command in order to form the launch command
+      * ``ls_extra_args``: additional arguments to append to the launch command
     """
 
     @abstractmethod
@@ -326,12 +332,33 @@ class LanguageServerDependencyProviderBaseCommand(LanguageServerDependencyProvid
         """
 
     def create_launch_command(self) -> list[str]:
+        # obtain base command
         ls_path = self._custom_settings.get("ls_path", None)
         if ls_path is not None:
             base_command = [ls_path]
         else:
             base_command = self._create_default_base_command()
-        return self._create_launch_command_from_base_command(list(base_command))
+
+        # create launch command from base command
+        ls_args = self._custom_settings.get("ls_args")
+        if ls_args is not None:
+            if not isinstance(ls_args, list):
+                log.warning("The 'ls_args' setting should be a list of strings. Ignoring the provided value: %s", ls_args)
+                ls_args = None
+        if ls_args is not None:
+            cmd = list(base_command) + ls_args
+        else:
+            cmd = self._create_launch_command_from_base_command(list(base_command))
+
+        # add user-provided extra arguments (if any)
+        ls_extra_args = self._custom_settings.get("ls_extra_args", [])
+        if ls_extra_args:
+            if not isinstance(ls_extra_args, list):
+                log.warning("The 'ls_extra_args' setting should be a list of strings. Ignoring the provided value: %s", ls_extra_args)
+            else:
+                cmd = cmd + ls_extra_args
+
+        return cmd
 
 
 class LanguageServerDependencyProviderSinglePath(LanguageServerDependencyProviderBaseCommand, ABC):