Sasslint precommit hook (elastic#28095)

* Remove SCSS linting from dev server

* Add sasslint to precommit hook

package.json

@@ -396,8 +396,8 @@
     "ts-node": "^7.0.1",
     "tslint": "^5.11.0",
     "tslint-config-prettier": "^1.15.0",
-    "tslint-plugin-prettier": "^2.0.0",
     "tslint-microsoft-contrib": "^6.0.0",
+    "tslint-plugin-prettier": "^2.0.0",
     "typescript": "^3.0.3",
     "vinyl-fs": "^3.0.2",
     "xml2js": "^0.4.19",

src/dev/file.ts

@@ -48,6 +48,10 @@ export class File {
     return this.ext === '.ts' || this.ext === '.tsx';
   }
 
+  public isSass() {
+    return this.ext === '.sass' || this.ext === '.scss';
+  }
+
   public isFixture() {
     return this.relativePath.split(sep).includes('__fixtures__');
   }

src/dev/run_precommit_hook.js

@@ -20,6 +20,7 @@
 import { run, combineErrors } from './run';
 import * as Eslint from './eslint';
 import * as Tslint from './tslint';
+import * as Sasslint from './sasslint';
 import { getFilesForCommit, checkFileCasing } from './precommit_hook';
 
 run(async ({ log }) => {
@@ -32,7 +33,7 @@ run(async ({ log }) => {
     errors.push(error);
   }
 
-  for (const Linter of [Eslint, Tslint]) {
+  for (const Linter of [Eslint, Tslint, Sasslint]) {
     const filesToLint = Linter.pickFilesToLint(log, files);
     if (filesToLint.length > 0) {
       try {

src/dev/sasslint/index.js

@@ -0,0 +1,21 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+export { pickFilesToLint } from './pick_files_to_lint';
+export { lintFiles } from './lint_files';

src/dev/sasslint/lint_files.js

@@ -0,0 +1,59 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import sassLint from 'sass-lint';
+import path from 'path';
+import { createFailError } from '../run';
+
+/**
+ * Lints a list of files with eslint. eslint reports are written to the log
+ * and a FailError is thrown when linting errors occur.
+ *
+ * @param  {ToolingLog} log
+ * @param  {Array<File>} files
+ * @return {undefined}
+ */
+export function lintFiles(log, files) {
+  const paths = files.map(file => file.getRelativePath());
+
+  const report = sassLint.lintFiles(
+    paths.join(', '),
+    {},
+    path.resolve(__dirname, '..', '..', '..', '.sass-lint.yml')
+  );
+
+  const failTypes = Object.keys(
+    report.reduce(
+      (failTypes, reportEntry) => {
+        if (reportEntry.warningCount > 0) failTypes.warning = true;
+        if (reportEntry.errorCount > 0) failTypes.errors = true;
+        return failTypes;
+      },
+      {}
+    )
+  );
+
+  if (!failTypes.length) {
+    log.success('[sasslint] %d files linted successfully', files.length);
+    return;
+  }
+
+  log.error(sassLint.format(report));
+  throw createFailError(`[sasslint] ${failTypes.join(' & ')}`, 1);
+}

src/dev/sasslint/pick_files_to_lint.js

@@ -0,0 +1,44 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import fs from 'fs';
+import { safeLoad } from 'js-yaml';
+import { makeRe } from 'minimatch';
+import path from 'path';
+
+// load the include globs from .sass-lint.yml and convert them to regular expressions for filtering files
+const sassLintPath = path.resolve(__dirname, '..', '..', '..', '.sass-lint.yml');
+const sassLintConfig = safeLoad(fs.readFileSync(sassLintPath));
+const { files: { include: includeGlobs } } = sassLintConfig;
+const includeRegex = includeGlobs.map(glob => makeRe(glob));
+
+function matchesInclude(file) {
+  for (let i = 0; i < includeRegex.length; i++) {
+    if (includeRegex[i].test(file.relativePath)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+export function pickFilesToLint(log, files) {
+  return files
+    .filter(file => file.isSass())
+    .filter(matchesInclude);
+}