Minor fixes

- Replaced the hardcoded nvm.sh path with path computed from NVM_DIR.
- Used require('paht').join to build paths, for more portability.
- Applied 'nvmVersion' input parameter.
- 'nvm use \<version\>' can be run from anywhere in the repo, since
  it only impacts the shell environment variables.

iCubTelemVizServer/openMctServerHandler.js

@@ -1,5 +1,8 @@
 "use strict";
 
+// Import utilities for working with file and directory paths.
+const path = require('path');
+
 function OpenMctServerHandler(outputCallback) {
     // Create a child process spawn for later setting the NVM version and running the server
     this.childProcess = require('child_process');
@@ -15,31 +18,30 @@ OpenMctServerHandler.prototype.setNvmVersion = function (nvmVersion) {
 
     // Build the string of shell commands
     const homeDir = process.env.HOME;
-    const cmdString = [
-        '. /Users/nunoguedelha/.nvm/nvm.sh 1> /dev/null' // Load the NVM function script
-        + '&& nvm use v14.17.0 1> /dev/null'               // Set the NVM version
-        + '&& echo {\\"NVM_INC\\":\\"$NVM_INC\\", \\"NVM_CD_FLAGS\\":\\"$NVM_CD_FLAGS\\", \\"NVM_BIN\\":\\"$NVM_BIN\\"}' // Return the updated NVM path (env. variables)
-    ];
-    const execPath = [process.cwd() + '/../openmctStaticServer'];
+    const cmdString =
+        '. ' + path.join(process.env.NVM_DIR, 'nvm.sh') + ' 1> /dev/null ' +     // Load the NVM function script
+        '&& nvm use ' + nvmVersion + ' 1> /dev/null ' +                          // Set the NVM version
+        '&& echo {\\"NVM_INC\\":\\"$NVM_INC\\", \\"NVM_CD_FLAGS\\":\\"$NVM_CD_FLAGS\\", \\"NVM_BIN\\":\\"$NVM_BIN\\"}'; // Return the updated NVM path (env. variables)
     try {
-        const stdout = this.childProcess.execSync(cmdString, {shell:'bash',cwd:execPath, timeout: 3000});
+        const stdout = this.childProcess.execSync(cmdString, {shell: 'bash', timeout: 3000});
         this.nvmVars = JSON.parse(stdout.toString());
         this.nvmVersion = nvmVersion;
-        return {status: 'OK', message: 'Updated NVM config in spawned shell: '+stdout.toString()+'\n'};
-    }
-    catch (error) {
+        return {status: 'OK', message: 'Updated NVM config in spawned shell: ' + stdout.toString() + '\n'};
+    } catch (error) {
         this.nvmVersion = 'default';
         return {status: 'ERROR', message: 'command "nvm use version" failed!'};
     }
 }
 
 OpenMctServerHandler.prototype.start = function () {
+    // Check if the server is already running
     if (this.isOn()) {
         return {status: 'WARNING', msg: 'OpenMCT server already running.'};
     } else {
         const embeddedThis = this;
         // Start the process
-        let npmStart = this.childProcess.spawn('npm', ['start']);
+        const execPath = path.join(process.cwd(), '..', 'openmctStaticServer');
+        let npmStart = this.childProcess.spawn('npm', ['start'],{shell: 'bash', cwd: execPath);
         // Set the output callbacks
         npmStart.stdout.on('data', function (data) {
             this.outputCallback('stdout: ' + data);