Merge pull request #830 from NativeScript/fatme/npm-install

Execute npm install only when node_modules folder does not exist

Author: Fatme

lib/services/plugins-service.ts

@@ -130,11 +130,15 @@ export class PluginsService implements IPluginsService {
 	}
 
 	public ensureAllDependenciesAreInstalled(): IFuture<void> {
-		let command = "npm install ";
-		if(this.$options.ignoreScripts) {
-			command += "--ignore-scripts";
-		}
-		return this.$childProcess.exec(command, { cwd: this.$projectData.projectDir });
+		return (() => {
+			if(!this.$fs.exists(path.join(this.$projectData.projectDir, constants.NODE_MODULES_FOLDER_NAME)).wait()) {
+				let command = "npm install ";
+				if(this.$options.ignoreScripts) {
+					command += "--ignore-scripts";
+				}
+				this.$childProcess.exec(command, { cwd: this.$projectData.projectDir }).wait();
+			}
+		}).future<void>()();
 	}
 
 	public getAllInstalledPlugins(): IFuture<IPluginData[]> {