fix: Load source map only from last directive (#31)

* Load source map only from last directive

* Remove \r in test input, avoid issue running test with CRLF fixtures

Author: zuohaocheng

index.js

@@ -8,7 +8,8 @@ var path = require("path");
 var async = require("async");
 var loaderUtils = require("loader-utils");
 
-var baseRegex = "\\s*[@#]\\s*sourceMappingURL\\s*=\\s*([^\\s]*)",
+// Matches only the last occurrence of sourceMappingURL
+var baseRegex = "\\s*[@#]\\s*sourceMappingURL\\s*=\\s*([^\\s]*)(?![\S\s]*sourceMappingURL)",
 	// Matches /* ... */ comments
 	regex1 = new RegExp("/\\*"+baseRegex+"\\s*\\*/"),
 	// Matches // .... comments

test/fixtures/multi-source-map.js

@@ -0,0 +1,4 @@
+with SourceMap
+anInvalidDirective = "\n/*# sourceMappingURL=data:application/json;base64," + btoa(unescape(encodeURIComponent(JSON.stringify(sourceMap)))) + " */";
+//    @    sourceMappingURL    =    data:application/source-map;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiaW5saW5lLXNvdXJjZS1tYXAuanMiLCJzb3VyY2VzIjpbImlubGluZS1zb3VyY2UtbWFwLnR4dCJdLCJzb3VyY2VzQ29udGVudCI6WyJ3aXRoIFNvdXJjZU1hcCJdLCJtYXBwaW5ncyI6IkFBQUEifQ==
+// comment

test/index.test.js

@@ -33,7 +33,9 @@ function execLoader(filename, callback) {
 			return this.callback;
 		}
 	};
-	var res = loader.call(context, fs.readFileSync(filename, "utf-8"));
+	// Remove CRs to make test line ending invariant
+	var fixtureContent = fs.readFileSync(filename, "utf-8").replace(/\r/g, '');
+	var res = loader.call(context, fixtureContent);
 	if(!async) return callback(null, res, null, deps, warns);
 }
 
@@ -107,6 +109,24 @@ describe("source-map-loader", function() {
 			done();
 		});
 	});
+	it("should use last SourceMap directive", function (done) {
+		execLoader(path.join(__dirname, "fixtures", "multi-source-map.js"), function (err, res, map, deps, warns) {
+			should.equal(err, null);
+			warns.should.be.eql([]);
+			should.equal(res, "with SourceMap\nanInvalidDirective = \"\\n/*# sourceMappingURL=data:application/json;base64,\" + btoa(unescape(encodeURIComponent(JSON.stringify(sourceMap)))) + \" */\";\n// comment"),
+				map.should.be.eql({
+					"version": 3,
+					"file": "inline-source-map.js",
+					"sources": [
+						"inline-source-map.txt"
+					],
+					"sourcesContent": ["with SourceMap"],
+					"mappings": "AAAA"
+				});
+			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);