[test] add sourceMap test against relative sources

test/mocha/input-sourcemaps.js

@@ -3,12 +3,10 @@ var assert = require("assert");
 var SourceMapConsumer = require("source-map").SourceMapConsumer;
 
 describe("input sourcemaps", function() {
-    var transpiled = '"use strict";\n\n' +
+    var transpilemap, map;
-        'var foo = function foo(x) {\n  return "foo " + x;\n};\n' +
-        'console.log(foo("bar"));\n\n' +
-        '//# sourceMappingURL=bundle.js.map';
 
-    var transpilemap = {
+    function getMap() {
+      return {
           "version": 3,
           "sources": ["index.js"],
           "names": [],
@@ -16,18 +14,43 @@ describe("input sourcemaps", function() {
           "file": "bundle.js",
           "sourcesContent": ["let foo = x => \"foo \" + x;\nconsole.log(foo(\"bar\"));"]
       };
+    }
+
+    function prepareMap(sourceMap) {
+        var transpiled = '"use strict";\n\n' +
+            'var foo = function foo(x) {\n  return "foo " + x;\n};\n' +
+            'console.log(foo("bar"));\n\n' +
+            '//# sourceMappingURL=bundle.js.map';
+
+        transpilemap = sourceMap || getMap();
 
         var result = Uglify.minify(transpiled, {
             fromString: true,
             inSourceMap: transpilemap,
             outSourceMap: true
         });
-    var map = new SourceMapConsumer(result.map);
+
+        map = new SourceMapConsumer(result.map);
+    }
+
+    beforeEach(function () {
+      prepareMap();
+    });
 
     it("Should copy over original sourcesContent", function() {
         assert.equal(map.sourceContentFor("index.js"), transpilemap.sourcesContent[0]);
     });
 
+    it("Should copy sourcesContent if sources are relative", function () {
+        var relativeMap = getMap();
+        relativeMap.sources = ['./index.js'];
+
+        prepareMap(relativeMap);
+        assert.notEqual(map.sourcesContent, null);
+        assert.equal(map.sourcesContent.length, 1);
+        assert.equal(map.sourceContentFor("index.js"), transpilemap.sourcesContent[0]);
+    });
+
     it("Final sourcemap should not have invalid mappings from inputSourceMap (issue #882)", function() {
         // The original source has only 2 lines, check that mappings don't have more lines