fix: Handle exception on loading invalid base64 source maps (#53)

Author: zuohaocheng

index.js

@@ -15,7 +15,7 @@ var baseRegex = "\\s*[@#]\\s*sourceMappingURL\\s*=\\s*([^\\s]*)(?![\\S\\s]*sourc
 	// Matches // .... comments
 	regex2 = new RegExp("//"+baseRegex+"($|\n|\r\n?)"),
 	// Matches DataUrls
-	regexDataUrl = /data:[^;\n]+(?:;charset=[^;\n]+)?;base64,(.*)/;
+	regexDataUrl = /data:[^;\n]+(?:;charset=[^;\n]+)?;base64,([a-zA-Z0-9+/]+={0,2})/;
 
 module.exports = function(input, inputMap) {
 	this.cacheable && this.cacheable();
@@ -28,7 +28,16 @@ module.exports = function(input, inputMap) {
 		var dataUrlMatch = regexDataUrl.exec(url);
 		var callback = this.async();
 		if(dataUrlMatch) {
-			processMap(JSON.parse((new Buffer(dataUrlMatch[1], "base64")).toString()), this.context, callback);
+			var mapBase64 = dataUrlMatch[1];
+			var mapStr = (new Buffer(mapBase64, "base64")).toString();
+			var map;
+			try {
+				map = JSON.parse(mapStr)
+			} catch (e) {
+				emitWarning("Cannot parse inline SourceMap '" + mapBase64.substr(0, 50) + "': " + e);
+				return untouched();				
+			}
+			processMap(map, this.context, callback);
 		} else {
 			resolve(this.context, loaderUtils.urlToRequest(url), function(err, result) {
 				if(err) {

test/fixtures/invalid-inline-source-map.js

@@ -0,0 +1,3 @@
+without SourceMap
+// @sourceMappingURL=data:application/source-map;base64,"something invalid"
+// comment

test/fixtures/invalid-inline-source-map2.js

@@ -0,0 +1,3 @@
+without SourceMap
+// @sourceMappingURL=data:application/source-map;base64,invalid/base64=
+// comment

test/index.test.js

@@ -127,6 +127,28 @@ describe("source-map-loader", function() {
 			done();
 		});
 	});
+	it("should skip invalid base64 SourceMap", function (done) {
+		execLoader(path.join(__dirname, "fixtures", "invalid-inline-source-map.js"), function (err, res, map, deps, warns) {
+			should.equal(err, null);
+			warns.should.be.eql([]);
+			should.equal(res, "without SourceMap\n// @sourceMappingURL=data:application/source-map;base64,\"something invalid\"\n// comment");
+			should.equal(map, null);
+			deps.should.be.eql([]);
+			done();
+		});
+	});
+	it("should warn on invalid base64 SourceMap", function (done) {
+		execLoader(path.join(__dirname, "fixtures", "invalid-inline-source-map2.js"), function (err, res, map, deps, warns) {
+			should.equal(err, null);
+			warns.should.matchEach(
+				new RegExp("Cannot parse inline SourceMap 'invalid\/base64=': SyntaxError: Unexpected token")
+			);
+			should.equal(res, "without SourceMap\n// @sourceMappingURL=data:application/source-map;base64,invalid/base64=\n// comment");
+			should.equal(map, null);
+			deps.should.be.eql([]);
+			done();
+		});
+	});
 	it("should warn on missing SourceMap", function(done) {
 		execLoader(path.join(__dirname, "fixtures", "missing-source-map.js"), function(err, res, map, deps, warns) {
 			should.equal(err, null);