fix(grunt-purgecss): Fix plugin not ouputting all files (#723)

* Add additional .css files

* Add failling test: grunt not processing all files

* Wait for all files being purged before returning the result

* Manual code styling

Author: vnctaing

packages/grunt-purgecss/Gruntfile.js

@@ -9,6 +9,9 @@ module.exports = grunt => {
           content: ['./__tests__/fixtures/src/simple/**/*.html']
         },
         files: {
+          '__tests__/tmp/menu.css': ['__tests__/fixtures/src/menu.css'],
+          '__tests__/tmp/profile.css': ['__tests__/fixtures/src/profile.css'],
+          '__tests__/tmp/footer.css': ['__tests__/fixtures/src/footer.css'],
           '__tests__/tmp/simple.css': ['__tests__/fixtures/src/simple/simple.css']
         }
       }
@@ -21,4 +24,4 @@ module.exports = grunt => {
   // By default, lint and run all tests.
   grunt.registerTask('default', ['purgecss']);
 
-};
+};

packages/grunt-purgecss/__tests__/fixtures/expected/footer.css

@@ -0,0 +1,3 @@
+.footer-unused-class {
+    background: black;
+}

packages/grunt-purgecss/__tests__/fixtures/expected/menu.css

@@ -0,0 +1,3 @@
+.menu-unused-class {
+    background: red;
+}

packages/grunt-purgecss/__tests__/fixtures/expected/profile.css

@@ -0,0 +1,3 @@
+.profile-unused-class {
+    background: hotpink;
+}

packages/grunt-purgecss/__tests__/fixtures/src/footer.css

@@ -1,5 +1,6 @@
 import { execSync } from "child_process";
 import fs from "fs";
+import path from "path";
 
 describe("Purgecss grunt plugin", () => {
   const cwd = process.cwd();
@@ -9,18 +10,31 @@ describe("Purgecss grunt plugin", () => {
     execSync("npx grunt");
   });
 
+  function emptyFolder(directory: string) {
+    fs.readdir(directory, (err, files) => {
+      if (err) throw err;
+
+      for (const file of files) {
+        fs.unlink(path.join(directory, file), err => {
+          if (err) throw err;
+        });
+       }
+    });
+  }
+
   afterAll(() => {
+    emptyFolder(`${__dirname}/tmp`);
     process.chdir(cwd);
   });
 
-  const files = ["simple.css"];
+  const files = ["simple.css", "footer.css", "menu.css", "profile.css"];
   for (const file of files) {
     it(`remove unused css successfully: ${file}`, () => {
       const actual = fs.readFileSync(`${__dirname}/tmp/${file}`).toString();
       const expected = fs
         .readFileSync(`${__dirname}/fixtures/expected/${file}`)
         .toString();
-      expect(actual).toBe(expected);
+      expect(actual.replace(/\s/g, '')).toBe(expected.replace(/\s/g, ''));
     });
   }
 });

packages/grunt-purgecss/__tests__/fixtures/src/menu.css

@@ -19,9 +19,10 @@ function gruntPurgeCSS(grunt: IGrunt): void {
   grunt.registerMultiTask("purgecss", "Grunt plugin for PurgeCSS", function () {
     const done = this.async();
     const options = this.options<UserDefinedOptions>(defaultOptions);
+    const promisedPurgedFiles = [];
     for (const file of this.files) {
       const source = getAvailableFiles(grunt, file.src);
-      new PurgeCSS()
+      const purgedCss = new PurgeCSS()
         .purge({
           ...options,
           css: source,
@@ -34,12 +35,15 @@ function gruntPurgeCSS(grunt: IGrunt): void {
           grunt.file.write(file.dest, purgeCSSResults[0].css);
           // Print a success message
           grunt.log.writeln(`File "${file.dest}" created.`);
-          done();
         })
-        .catch(() => {
-          done(false);
-        });
+
+        promisedPurgedFiles.push(purgedCss);
     }
+      Promise.all(promisedPurgedFiles)
+          .then(() => {
+              done();
+      }).catch(() => done(false))
+
   });
 }