Breaking: Avoid error in write when sourceMap property did not exist …

…on file (closes #5)

index.js

@@ -81,9 +81,12 @@ function write(file, destPath, options, callback) {
 		return callback(new Error(PLUGIN_NAME + '-write: Not a vinyl file'));
 	}
 
-	// Throw an error if the file doesn't have a sourcemap
-	if (!file.sourceMap) {
-		return callback(new Error(PLUGIN_NAME + '-write: No sourcemap found'));
+	if (file.isStream()) {
+		return callback(new Error(PLUGIN_NAME + '-write: Streaming not supported'));
+	}
+
+	if (file.isNull() || !file.sourceMap) {
+		return callback(null, file);
 	}
 
 	// TODO: don't mutate - needs test too

test/write.js

@@ -22,19 +22,14 @@ function makeSourceMap() {
 	};
 }
 
-function makeFile(addSourcemap) {
-	if (addSourcemap === undefined) {
-		addSourcemap = true;
-	}
+function makeFile() {
 	var file = new File({
 		cwd: __dirname,
 		base: path.join(__dirname, 'assets'),
 		path: path.join(__dirname, 'assets', 'helloworld.js'),
-		contents: new Buffer(sourceContent)
+		contents: new Buffer(sourceContent),
+		sourceMap: makeSourceMap(),
 	});
-	if (addSourcemap === true) {
-		file.sourceMap = makeSourceMap();
-	}
 	return file;
 }
 
@@ -83,11 +78,14 @@ describe('write', function() {
 		});
 	});
 
-	it('should return an error when no sourcemap is found on the file', function(done) {
-		var file = makeFile(false);
-		sourcemaps.write(file, function(err) {
-			expect(err instanceof Error && err.message === 'vinyl-sourcemap-write: No sourcemap found').toExist();
-			done();
+	it('calls back with the untouched file if sourceMap property does not exist', function(done) {
+		var file = makeFile();
+		delete file.sourceMap;
+		sourcemaps.write(file, function(err, outFile) {
+			expect(err).toNotExist();
+			expect(file).toExist();
+			expect(outFile).toEqual(file);
+			done(err);
 		});
 	});