build: add linter scripts and use it on travis

PR-URL: #260
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

.travis.yml

@@ -112,6 +112,20 @@ matrix:
       script: npm run test-all
       node_js: "10"
 
+    ##########
+    # Linter #
+    ##########
+
+    - name: "Linter"
+      sudo: required
+      dist: trusty
+      before_install:
+        - sudo apt-get -qq update
+        - sudo apt-get install lldb-3.9 liblldb-3.9-dev -y
+      install: npm install
+      script: npm run linter
+      node_js: "10"
+
   # Allow the nightly installs to fail
   allow_failures:
 

package.json

@@ -25,6 +25,7 @@
     "codecov-upload-cc": "codecov --disable=gcov --file=coverage-cc.info",
     "codecov-upload-js": "codecov --disable=gcov --file=coverage-js.lcov",
     "codecov-upload": "npm run codecov-upload-cc && npm run codecov-upload-js",
+    "linter": "node scripts/linter.js",
     "format": "clang-format -i src/*"
   },
   "repository": {

scripts/linter.js

@@ -0,0 +1,41 @@
+'use strict';
+
+const { getNativeBinary } = require("clang-format");
+const { exec } = require("child_process");
+const { readdir, readFile } = require("fs");
+
+const dirtyFiles = [];
+
+process.on("exit", () => {
+  if (dirtyFiles.length == 0) {
+    return;
+  }
+  process.exitCode = 1;
+  process._rawDebug("The following files are not formatted correctly:");
+  for (let file of dirtyFiles) {
+    process._rawDebug(`  ${file}`);
+  }
+
+});
+
+readdir("./src/", (err, files) => {
+  for (let file of files) {
+    readFile(`./src/${file}`, {encoding: 'utf8'}, (err, data) => {
+      if (err) {
+        console.error(err);
+        process.exitCode = 2;
+        return;
+      }
+      exec(`${getNativeBinary()} src/${file}`, {maxBuffer: 1024 * 1024 * 5}, (err, stdout, stderr) => {
+        if (err) {
+          console.error(err);
+          process.exitCode = 2;
+          return;
+        }
+        if (stdout.trim() != data.trim()) {
+          dirtyFiles.push(file);
+        }
+      });
+    });
+  }
+});