fix: merge getExePath into spawn

Author: aminya

README.md

@@ -85,10 +85,10 @@ Note that you will also need to add various entries to the `providedServices` an
 
 ### Minimal example (General LSP exe)
 
-If the LSP is a general executable (not a JavaScript file), you should use `spawn` inside `startServerProcess`. `getExePath` is a cross-platform utility function to get the exe path for the given exe name (under the `bin/platform-arch/exeName` by default or `exeName` if the file doesn't exist).
+If the LSP is a general executable (not a JavaScript file), you should use `spawn` inside `startServerProcess`.
 
 ```javascript
-const {AutoLanguageClient, getExePath} = require('atom-languageclient')
+const {AutoLanguageClient} = require('atom-languageclient')
 
 class DLanguageClient extends AutoLanguageClient {
   getGrammarScopes () { return [ 'source.d' ] }
@@ -97,7 +97,8 @@ class DLanguageClient extends AutoLanguageClient {
 
   startServerProcess (projectPath) {
     return super.spawn(
-      getExePath('serve-d'),    // path to the LSP executable (or the exe name if it is on the PATH)
+      'serve-d',                // the `name` or `path` of the executable
+                                // if the `name` is provided it checks `bin/platform-arch/exeName` by default, and if doesn't exists uses the `exeName` on the PATH
       [],                       // args passed to spawn the exe
       { cwd: projectPath }      // child process spawn options
     )

lib/auto-languageclient.ts

@@ -279,13 +279,27 @@ export default class AutoLanguageClient {
     await this._serverManager.stopAllServers();
   }
 
-  /** Spawn a general language server
-   *  Use this inside the `startServerProcess` override if the language server is a general executable
-   *  Also see the `spawnChildNode` method
+  /**
+   * Spawn a general language server.
+   * Use this inside the `startServerProcess` override if the language server is a general executable.
+   * Also see the `spawnChildNode` method.
+   * If the name is provided as the first argument, it checks `bin/platform-arch/exeName` by default, and if doesn't exists uses the exe on PATH.
+   * For example on Windows x64, by passing `serve-d`, `bin/win32-x64/exeName.exe` is spawned by default.
+   * @param exe the `name` or `path` of the executable
+   * @param args args passed to spawn the exe. Defaults to `[]`.
+   * @param options: child process spawn options. Defaults to `{}`.
+   * @param rootPath the path of the folder of the exe file. Defaults to `join("bin", `${process.platform}-${process.arch}`)`.
+   * @param exeExtention the extention of the exe file. Defaults to `process.platform === "win32" ? ".exe" : ""`
    */
-  protected spawn(exe: string, args: string[], options: cp.SpawnOptions = {}): LanguageServerProcess {
+  protected spawn(
+    exe: string,
+    args: string[] = [],
+    options: cp.SpawnOptions = {},
+    rootPath = Utils.rootPathDefault,
+    exeExtention = Utils.exeExtentionDefault
+  ): LanguageServerProcess {
     this.logger.debug(`starting "${exe} ${args.join(' ')}"`);
-    return cp.spawn(exe, args, options);
+    return cp.spawn(Utils.getExePath(exe, rootPath, exeExtention), args, options);
   }
 
   /** Spawn a language server using Atom's Nodejs process

lib/utils.ts

@@ -115,6 +115,9 @@ export function promiseWithTimeout<T>(ms: number, promise: Promise<T>): Promise<
 }
 
 
+export const rootPathDefault = join("bin", `${process.platform}-${process.arch}`);
+export const exeExtentionDefault = process.platform === "win32" ? ".exe" : "";
+
 /** Finds an exe file in the package assuming it is placed under `rootPath/platform-arch/exe`. If the exe file did not exist,
  * the given name is returned.
  * For example on Windows x64, if the `exeName` is `serve-d`, it returns the absolute path to `./bin/win32-x64/exeName.exe`, and
@@ -123,11 +126,7 @@ export function promiseWithTimeout<T>(ms: number, promise: Promise<T>): Promise<
  * @param rootPath the path of the folder of the exe file. Defaults to 'join("bin", `${process.platform}-${process.arch}`)'
  * @param exeExtention the extention of the exe file. Defaults to `process.platform === "win32" ? ".exe" : ""`
  */
-export function getExePath(
- exeName: string,
- rootPath = join("bin", `${process.platform}-${process.arch}`),
- exeExtention = process.platform === "win32" ? ".exe" : ""
-): string {
+export function getExePath(exeName: string, rootPath = rootPathDefault, exeExtention = exeExtentionDefault): string {
  const exePath = resolve(join(rootPath, `${exeName}${exeExtention}`));
  if (existsSync(exePath)) {
    return exePath