suppress warnings with --silent (closes #1213)

bin/src/help.md

@@ -23,6 +23,7 @@ Basic options:
 --no-indent              Don't indent result
 --environment <values>   Settings passed to config file (see example)
 --no-conflict            Generate a noConflict method for UMD globals
+--silent                 Don't print warnings
 --intro                  Content to insert at top of bundle (inside wrapper)
 --outro                  Content to insert at end of bundle (inside wrapper)
 --banner                 Content to insert at top of bundle (outside wrapper)

bin/src/runRollup.js

@@ -151,6 +151,10 @@ function execute ( options, command ) {
 		external = ( optionsExternal || [] ).concat( commandExternal );
 	}
 
+	if ( command.silent ) {
+		options.onwarn = () => {};
+	}
+
 	if ( !options.onwarn ) {
 		const seen = new Set();
 

test/cli/silent/_config.js

@@ -0,0 +1,5 @@
+module.exports = {
+	description: 'does not print warnings with --silent',
+	command: 'rollup -i main.js -f cjs --silent',
+	stderr: ``
+};

test/cli/silent/_expected.js

@@ -0,0 +1,5 @@
+'use strict';
+
+var foo = 42;
+
+assert.equal( foo, 42 );

test/cli/silent/foo.js

@@ -0,0 +1 @@
+export var foo = 42;

test/cli/silent/main.js

@@ -0,0 +1,3 @@
+import { foo, bar } from './foo.js';
+
+assert.equal( foo, 42 );

test/test.js

@@ -58,6 +58,10 @@ function loader ( modules ) {
 	};
 }
 
+function deindent ( str ) {
+	return str.slice( 1 ).replace( /^\t+/gm, '' ).replace( /\s+$/gm, '' ).trim();
+}
+
 function compareWarnings ( actual, expected ) {
 	assert.deepEqual(
 		actual.map( warning => {
@@ -72,7 +76,7 @@ function compareWarnings ( actual, expected ) {
 		}),
 		expected.map( warning => {
 			if ( warning.frame ) {
-				warning.frame = warning.frame.slice( 1 ).replace( /^\t+/gm, '' ).replace( /\s+$/gm, '' ).trim();
+				warning.frame = deindent( warning.frame );
 			}
 			return warning;
 		})
@@ -90,7 +94,7 @@ function compareError ( actual, expected ) {
 	}
 
 	if ( expected.frame ) {
-		expected.frame = expected.frame.slice( 1 ).replace( /^\t+/gm, '' ).replace( /\s+$/gm, '' ).trim();
+		expected.frame = deindent( expected.frame );
 	}
 
 	assert.deepEqual( actual, expected );
@@ -498,7 +502,11 @@ describe( 'rollup', function () {
 							}
 						}
 
-						if ( stderr ) console.error( stderr );
+						if ( 'stderr' in config ) {
+							assert.equal( deindent( config.stderr ), stderr.trim() );
+						} else if ( stderr ) {
+							console.error( stderr );
+						}
 
 						let unintendedError;