on second thoughts, dont auto-install. will cause problems in many cases

bin/getRollupWatch.js

@@ -1,43 +0,0 @@
-var chalk = require( 'chalk' );
-var relative = require( 'require-relative' );
-
-module.exports = function getRollupWatch () {
-	try {
-		watch = relative( 'rollup-watch', process.cwd() );
-		return Promise.resolve( watch );
-	} catch ( err ) {
-		if ( err.code === 'MODULE_NOT_FOUND' ) {
-			return installRollupWatch().then( () => {
-				return relative( 'rollup-watch', process.cwd() );
-			});
-		} else {
-			return Promise.reject( err );
-		}
-	}
-};
-
-function installRollupWatch () {
-	console.error( 'rollup --watch depends on the rollup-watch package, which could not be found. You can install it globally with ' + chalk.cyan( 'npm install -g rollup-watch' ) + '. Do this now? ' + chalk.green.bold( '[y/n]' ) );
-
-	process.stdin.setEncoding( 'utf8' );
-
-	return new Promise( ( fulfil, reject ) => {
-		process.stdin.on( 'readable', function () {
-			var chunk = process.stdin.read();
-			if ( !chunk ) return;
-
-			if ( /^y(?:es)?$/i.test( chunk ) ) {
-				console.error( 'installing rollup-watch...' );
-				child = require( 'child_process' ).exec( 'npm install --global rollup-watch', err => {
-					if ( err ) {
-						reject( err );
-					} else {
-						fulfil();
-					}
-				});
-			} else {
-				reject( new Error( 'aborted' ) );
-			}
-		});
-	});
-}

bin/handleError.js

@@ -30,7 +30,7 @@ var handlers = {
 	},
 
 	ROLLUP_WATCH_NOT_INSTALLED: function ( err ) {
-		console.error( chalk.red( 'failed to find or install rollup-watch' ) );
+		console.error( chalk.red( 'rollup --watch depends on the rollup-watch package, which could not be found. You can install it globally (recommended) with ' ) + chalk.cyan( 'npm install -g rollup-watch' ) );
 	},
 
 	WATCHER_MISSING_INPUT_OR_OUTPUT: function ( err ) {

bin/runRollup.js

@@ -1,8 +1,8 @@
 require( 'source-map-support' ).install();
 
 var path = require( 'path' );
+var relative = require( 'require-relative' );
 var handleError = require( './handleError' );
-var getRollupWatch = require( './getRollupWatch' );
 var chalk = require( 'chalk' );
 var rollup = require( '../' );
 
@@ -134,30 +134,35 @@ function execute ( options, command ) {
 				handleError({ code: 'WATCHER_MISSING_INPUT_OR_OUTPUT' });
 			}
 
-			getRollupWatch()
-				.then( watch => {
-					const watcher = watch( rollup, options );
-
-					watcher.on( 'event', event => {
-						switch ( event.code ) {
-							case 'STARTING':
-								console.error( 'checking rollup-watch version...' );
-								break;
-
-							case 'BUILD_START':
-								console.error( 'bundling...' );
-								break;
-
-							case 'BUILD_END':
-								console.error( 'bundled in ' + event.duration + 'ms. Watching for changes...' );
-								break;
-
-							default:
-								console.error( 'unknown event', event );
-						}
-					});
-				})
-				.catch( handleError );
+			try {
+				var watch = relative( 'rollup-watch', process.cwd() );
+				var watcher = watch( rollup, options );
+
+				watcher.on( 'event', event => {
+					switch ( event.code ) {
+						case 'STARTING':
+							console.error( 'checking rollup-watch version...' );
+							break;
+
+						case 'BUILD_START':
+							console.error( 'bundling...' );
+							break;
+
+						case 'BUILD_END':
+							console.error( 'bundled in ' + event.duration + 'ms. Watching for changes...' );
+							break;
+
+						default:
+							console.error( 'unknown event', event );
+					}
+				});
+			} catch ( err ) {
+				if ( err.code === 'MODULE_NOT_FOUND' ) {
+					err.code = 'ROLLUP_WATCH_NOT_INSTALLED';
+				}
+
+				handleError( err );
+			}
 		} else {
 			bundle( options ).catch( handleError );
 		}