Fix path resolving of equally named files

By looking into the previously resolved path first, we make sure to
resolve the correct file instead of a file which happens to have the
same name and is located in a directory which was added to the
node-sass include paths.

Fixes #165

Author: maoberlehner

.gitignore

@@ -29,4 +29,5 @@ Thumbs.db
 coverage
 dist
 node_modules
+!test/bugfix/*/files/node_modules
 !test/files/node_modules

packages/node-sass-magic-importer/src/functions/build-include-paths.spec.ts

@@ -26,12 +26,12 @@ describe(`buildIncludePaths()`, () => {
   test(`It should return an array with node-sass include paths and include path from previous file.`, () => {
     const buildIncludePaths = buildIncludePathsFactory(path);
 
-    const nodeSassIncludePaths = `/include/path1${path.delimiter}/include/path2`;
-    const previouslyResolvedPath = `/include/path3/file.scss`;
+    const nodeSassIncludePaths = `/include/include-path1${path.delimiter}/include/include-path2`;
+    const previouslyResolvedPath = `/include/previously-resolved-path/file.scss`;
     const expectedResult = [
-      `/include/path1`,
-      `/include/path2`,
-      `/include/path3`,
+      `/include/previously-resolved-path`,
+      `/include/include-path1`,
+      `/include/include-path2`,
     ];
 
     expect(buildIncludePaths(nodeSassIncludePaths, previouslyResolvedPath))

packages/node-sass-magic-importer/src/functions/build-include-paths.ts

@@ -5,12 +5,12 @@ export function buildIncludePathsFactory(
   path: IPath,
 ): IBuildIncludePaths {
   return (nodeSassIncludePaths: string, previouslyResolvedPath: string) => {
-    const includePathsSet = new Set(nodeSassIncludePaths.split(path.delimiter));
+    const includePaths = [];
 
     if (path.isAbsolute(previouslyResolvedPath)) {
-      includePathsSet.add(path.dirname(previouslyResolvedPath));
+      includePaths.push(path.dirname(previouslyResolvedPath));
     }
 
-    return [...includePathsSet] as string[];
+    return [...new Set([...includePaths, ...nodeSassIncludePaths.split(path.delimiter)])] as string[];
   };
 }

test/bugfix/165/files/_some-file.scss

@@ -0,0 +1,3 @@
+.some-file-1 {
+  content: 'some file 1';
+}

test/bugfix/165/files/node_modules/package/_some-file.scss

@@ -0,0 +1,5 @@
+.some-file-1 {
+  content: 'some file 1'; }
+
+.some-file-2 {
+  content: 'some file 2'; }

test/bugfix/165/files/node_modules/package/index.scss

@@ -0,0 +1,2 @@
+@import 'some-file';
+@import '~package';

test/bugfix/165/files/node_modules/package/package.json

@@ -0,0 +1,22 @@
+import * as fs from 'fs';
+import * as sass from 'node-sass';
+
+import * as magicImporter from '../../../packages/node-sass-magic-importer/dist/index';
+
+describe(`magicImporter()`, () => {
+  test(`It should start trying to resolve paths starting with the path of the parent file.`, () => {
+    const expectedResult = fs.readFileSync(`test/bugfix/165/files/resolve-from-parent.css`, {
+      encoding: `utf8`,
+    });
+    const result = sass.renderSync({
+      file: `test/bugfix/165/files/resolve-from-parent.scss`,
+      importer: magicImporter({
+        cwd: `${__dirname}/files`,
+      }),
+      // This is important for the test case!
+      includePaths: [`${__dirname}/files`],
+    }).css.toString();
+
+    expect(result).toBe(expectedResult);
+  });
+});