Simplify configuration/updates

This removes 'ignorePATH' and 'updateBehavior' config options
and instead introduces a simple 'manageHLS' setting, which
decides whether ghcup is used to install the appropriate HLS or not.

Author: hasufell

README.md

@@ -71,21 +71,26 @@ The environment _only will be visible for the lsp server_, not for other extensi
 
 ### Downloaded binaries
 
-This extension will download `haskell-language-server` binaries to a specific location depending on your system.
+This extension will download `haskell-language-server` binaries via an (internal) ghcup to a specific location depending
+on your system, unless you set the config option `haskell.manageHLS` to `false` (the default is `true`).
 
 It will download the newest version of haskell-language-server which has support for the required ghc.
 That means it could use an older version than the latest one, without the last features and bug fixes.
 For example, if a project needs ghc-8.10.4 the extension will download and use haskell-language-server-1.4.0, the lastest version which supported ghc-8.10.4. Even if the lastest global haskell language-server version is 1.5.1.
 
 If you find yourself running out of disk space, you can try deleting old versions of language servers in this directory. The extension will redownload them, no strings attached.
 
-| Platform | Path                                                                      |
-| -------- | ------------------------------------------------------------------------- |
-| macOS    | `~/Library/Application\ Support/Code/User/globalStorage/haskell.haskell/` |
-| Windows  | `%APPDATA%\Code\User\globalStorage\haskell.haskell`                       |
-| Linux    | `$HOME/.config/Code/User/globalStorage/haskell.haskell`                   |
+| Platform | Path                                                                            |
+| -------- | ------------------------------------------------------------------------------- |
+| macOS    | `~/Library/Application\ Support/Code/User/globalStorage/haskell.haskell/.ghcup` |
+| Windows  | `%APPDATA%\Code\User\globalStorage\haskell.haskell/ghcup`                       |
+| Linux    | `$HOME/.config/Code/User/globalStorage/haskell.haskell/.ghcup`                  |
 
-Note that if `haskell-language-server-wrapper`/`haskell-language-server` is already on the PATH or you have set the `haskell.serverExecutablePath` option, then the extension will launch it directly instead of downloading binaries, even if the version of the former is older then the latter.
+Note that if `haskell-language-server-wrapper`/`haskell-language-server` is already on the PATH or you have set the
+`haskell.serverExecutablePath` option, then the extension will try to launch it directly, and only fall back to
+downloading other binaries if these are unsuitable and `haskell.manageHLS` is set to `true`.
+
+You can also tell HLS to use your system provided ghcup by setting `haskell.useSystemGHCup` to `true` (default is `false`).
 
 ### Supported GHC versions
 

package.json

@@ -151,27 +151,11 @@
           "default": {},
           "markdownDescription": "Define environment variables for the language server."
         },
-        "haskell.updateBehavior": {
-          "scope": "machine",
-          "type": "string",
-          "enum": [
-            "keep-up-to-date",
-            "prompt",
-            "never-check"
-          ],
-          "enumDescriptions": [
-            "Always download the latest available version when it is published",
-            "Prompt before upgrading to a newer version",
-            "Don't check for newer versions"
-          ],
-          "default": "keep-up-to-date",
-          "markdownDescription": "Determine what to do when a new version of the language server is available."
-        },
-        "haskell.ignorePATH": {
+        "haskell.manageHLS": {
           "scope": "resource",
           "type": "boolean",
-          "default": false,
-          "description": "Whether to ignore haskell-language-server on PATH"
+          "default": true,
+          "description": "Let this extension manage required HLS versions via ghcup."
         },
         "haskell.useSystemGHCup": {
           "scope": "resource",

src/extension.ts

@@ -22,8 +22,8 @@ import {
 import { CommandNames } from './commands/constants';
 import { ImportIdentifier } from './commands/importIdentifier';
 import { DocsBrowser } from './docsBrowser';
-import { addPathToProcessPath, downloadGHCup, downloadHaskellLanguageServer, IEnvVars, validateHLSToolchain } from './hlsBinaries';
-import { directoryExists, executableExists, expandHomeDir, ExtensionLogger, resolvePathPlaceHolders } from './utils';
+import { addPathToProcessPath, findHaskellLanguageServer, IEnvVars, validateHLSToolchain } from './hlsBinaries';
+import { expandHomeDir, ExtensionLogger } from './utils';
 
 // The current map of documents & folders to language servers.
 // It may be null to indicate that we are in the process of launching a server,
@@ -96,49 +96,6 @@ export async function activate(context: ExtensionContext) {
   context.subscriptions.push(openOnHackageDisposable);
 }
 
-function findManualExecutable(logger: Logger, uri: Uri, folder?: WorkspaceFolder): string | null {
-  let exePath = workspace.getConfiguration('haskell', uri).serverExecutablePath;
-  if (exePath === '') {
-    return null;
-  }
-  logger.info(`Trying to find the server executable in: ${exePath}`);
-  exePath = resolvePathPlaceHolders(exePath, folder);
-  logger.log(`Location after path variables substitution: ${exePath}`);
-
-  if (!executableExists(exePath)) {
-    let msg = `serverExecutablePath is set to ${exePath}`;
-    if (directoryExists(exePath)) {
-      msg += ' but it is a directory and the config option should point to the executable file full path';
-    } else {
-      msg += " but it doesn't exist and it is not on the PATH";
-    }
-    throw new Error(msg);
-  }
-  return exePath;
-}
-
-/** Searches the PATH for whatever is set in serverVariant
- *
- * return null when **haskell.ignorePATH** set
- */
-function findLocalServer(context: ExtensionContext, logger: Logger, uri: Uri, folder?: WorkspaceFolder): string | null {
-  if (workspace.getConfiguration('haskell').get('ignorePATH') === true) {
-    logger.info('Ignoring haskell-language-server on PATH');
-    return null;
-  }
-  const exes: string[] = ['haskell-language-server-wrapper', 'haskell-language-server'];
-  logger.info(`Searching for server executables ${exes.join(',')} in $PATH`);
-  logger.info(`$PATH environment variable: ${process.env.PATH}`);
-  for (const exe of exes) {
-    if (executableExists(exe)) {
-      logger.info(`Found server executable in $PATH: ${exe}`);
-      return exe;
-    }
-  }
-
-  return null;
-}
-
 async function activeServer(context: ExtensionContext, document: TextDocument) {
   // We are only interested in Haskell files.
   if (
@@ -190,17 +147,11 @@ async function activateServerForFolder(context: ExtensionContext, uri: Uri, fold
   let serverExecutable;
   let addInternalServerPath: string | undefined; // if we download HLS, add that bin dir to PATH
   try {
-    // Try and find local installations first
-    serverExecutable = findManualExecutable(logger, uri, folder) ?? findLocalServer(context, logger, uri, folder);
-    if (serverExecutable === null) {
-      // If not, then try to download haskell-language-server binaries if it's selected
-      await downloadGHCup(context, logger);
-      serverExecutable = await downloadHaskellLanguageServer(context, logger, currentWorkingDir);
-      await validateHLSToolchain(serverExecutable, currentWorkingDir, logger);
-      addInternalServerPath = path.dirname(serverExecutable);
-      if (!serverExecutable) {
-        return;
-      }
+    serverExecutable = await findHaskellLanguageServer(context, logger, currentWorkingDir, folder);
+    await validateHLSToolchain(serverExecutable, currentWorkingDir, logger);
+    addInternalServerPath = path.dirname(serverExecutable);
+    if (!serverExecutable) {
+      return;
     }
   } catch (e) {
     if (e instanceof Error) {