fix: Bare imports not working sometimes (#579)

Fixes #566
Supersedes #577

Author: jhnns

lib/importsToResolve.js

@@ -3,7 +3,7 @@
 const path = require("path");
 const utils = require("loader-utils");
 
-const matchModuleImport = /^~([^\/]+|@[^\/]+[\/][^\/]+)$/g;
+const matchModuleImport = /^~([^\/]+|@[^\/]+[\/][^\/]+)$/;
 
 /**
  * When libsass tries to resolve an import, it uses a special algorithm.

test/index.test.js

@@ -205,7 +205,7 @@ describe("sass-loader", () => {
                     sourceMap.should.not.have.property("file");
                     sourceMap.should.have.property("sourceRoot", fakeCwd);
                     // This number needs to be updated if imports.scss or any dependency of that changes
-                    sourceMap.sources.should.have.length(11);
+                    sourceMap.sources.should.have.length(13);
                     sourceMap.sources.forEach(sourcePath =>
                         fs.existsSync(path.resolve(sourceMap.sourceRoot, sourcePath))
                     );

test/node_modules/module

@@ -22,3 +22,7 @@
 // See https://github.com/webpack-contrib/sass-loader/issues/556
 /* @import util */
 @import util
+/* @import ~module */
+@import ~module
+/* @import ~other-module */
+@import ~other-module

test/node_modules/other-module

@@ -23,4 +23,9 @@
 }
 // The local util file should take precedence over Node's util module
 // See https://github.com/webpack-contrib/sass-loader/issues/556
+/* @import "util"; */
 @import "util";
+/* @import "~module"; */
+@import "~module";
+/* @import "~other-module"; */
+@import "~other-module";