Fix import url parsing when from is a filter

The `from` keyword could be used as a node import filter, in such cases
and if whitespace is added around filters, extracting filters was not
working correctly.

Fixes #159

packages/node-sass-magic-importer/src/functions/parse-node-filters.spec.ts

@@ -77,6 +77,20 @@ describe(`parseNodeFilters()`, () => {
     expect(nodeFilters).toEqual(expectedResult);
   });
 
+  test(`It should handle spaces in node filters.`, () => {
+    const parseNodeFilters = parseNodeFiltersFactory();
+    const urlWithFilters = `[ at-rules, mixins, from ] from style.scss`;
+
+    const nodeFilters = parseNodeFilters(urlWithFilters);
+    const expectedResult = [
+      `at-rules`,
+      `mixins`,
+      `from`,
+    ];
+
+    expect(nodeFilters).toEqual(expectedResult);
+  });
+
   test(`It should trim empty filter from multi line URL.`, () => {
     const parseNodeFilters = parseNodeFiltersFactory();
     const urlWithFilters = `[

packages/node-sass-magic-importer/src/functions/parse-node-filters.ts

@@ -2,7 +2,7 @@ import { IFilterParser } from '../interfaces/IFilterParser';
 
 export function parseNodeFiltersFactory(): IFilterParser {
   return (url: string) => {
-    const filterDivider = /[\s]+from[\s]+/;
+    const filterDivider = /[\s]+from[\s]+(?!.*from)/;
 
     if (!filterDivider.test(url)) {
       return [];

packages/node-sass-magic-importer/src/functions/parse-selector-filters.ts

@@ -7,7 +7,7 @@ export function parseSelectorFiltersFactory(
   splitSelectorFilter: ISplitSelectorFilter,
 ): IParseSelectorFilters {
   return (url: string) => {
-    const filterDivider = /[\s]+from[\s]+/;
+    const filterDivider = /[\s]+from[\s]+(?!.*from)/;
 
     if (!filterDivider.test(url)) {
       return [];