Introduce code-analysis bot

.travis.yml

@@ -28,6 +28,7 @@ script:
   elif [ "$TEST_TYPE" = js ]
   then
 
+    cat <(echo eslint; npm run lint --silent -- --format=json; echo flow; flow --json) | GITHUB_TOKEN="af6ef0d15709bc91d""06a6217a5a826a226fb57b7" node bots/code-analysis-bot.js
     flow check && npm test -- '\/Libraries\/'
 
   elif [ "$TEST_TYPE" = packager ]

bots/code-analysis-bot.js

@@ -0,0 +1,242 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+'use strict';
+
+if (!process.env.TRAVIS_REPO_SLUG) {
+  console.error('Missing TRAVIS_REPO_SLUG. Example: facebook/react-native');
+  process.exit(1);
+}
+if (!process.env.GITHUB_TOKEN) {
+  console.error('Missing GITHUB_TOKEN. Example: 5fd88b964fa214c4be2b144dc5af5d486a2f8c1e');
+  process.exit(1);
+}
+if (!process.env.TRAVIS_PULL_REQUEST) {
+  console.error('Missing TRAVIS_PULL_REQUEST. Example: 4687');
+  process.exit(1);
+}
+
+var GitHubApi = require('github');
+var path = require('path');
+
+var github = new GitHubApi({
+  version: '3.0.0',
+});
+
+github.authenticate({
+  type: 'oauth',
+  token: process.env.GITHUB_TOKEN,
+});
+
+function push(arr, key, value) {
+  if (!arr[key]) {
+    arr[key] = [];
+  }
+  arr[key].push(value);
+}
+
+/**
+ * There is unfortunately no standard format to report an error, so we have
+ * to write a specific converter for each tool we want to support.
+ *
+ * Those functions take a json object as input and fill the output with the
+ * following format:
+ *
+ * { [ path: string ]: Array< { message: string, line: number }> }
+ *
+ * This is an object where the keys are the path of the files and values
+ * is an array of objects of the shape message and line.
+ */
+var converters = {
+  raw: function(output, input) {
+    for (var key in input) {
+      input[key].forEach(function(message) {
+        push(output, key, message);
+      });
+    }
+  },
+
+  flow: function(output, input) {
+    if (!input || !input.errors) {
+      return;
+    }
+
+    input.errors.forEach(function(error) {
+      push(output, error.message[0].path, {
+        message: error.message.map(message => message.descr).join(' '),
+        line: error.message[0].line,
+      });
+    });
+  },
+
+  eslint: function(output, input) {
+    if (!input) {
+      return;
+    }
+
+    input.forEach(function(file) {
+      file.messages.forEach(function(message) {
+        push(output, file.filePath, {
+          message: message.ruleId + ': ' + message.message,
+          line: message.line,
+        });
+      });
+    });
+  }
+};
+
+function getShaFromPullRequest(user, repo, number, callback) {
+  github.pullRequests.get({user, repo, number}, (error, res) => {
+    if (error) {
+      console.log(error);
+      return;
+    }
+    callback(res.head.sha);
+  });
+}
+
+function getFilesFromCommit(user, repo, sha, callback) {
+  github.repos.getCommit({user, repo, sha}, (error, res) => {
+    if (error) {
+      console.log(error);
+      return;
+    }
+    callback(res.files);
+  });
+}
+
+
+/**
+ * Sadly we can't just give the line number to github, we have to give the
+ * line number relative to the patch file which is super annoying. This
+ * little function builds a map of line number in the file to line number
+ * in the patch file
+ */
+function getLineMapFromPatch(patchString) {
+  var diffLineIndex = 0;
+  var fileLineIndex = 0;
+  var lineMap = {};
+
+  patchString.split('\n').forEach((line) => {
+    if (line.match(/^@@/)) {
+      fileLineIndex = line.match(/\+([0-9]+)/)[1] - 1;
+      return;
+    }
+
+    diffLineIndex++;
+    if (line[0] !== '-') {
+      fileLineIndex++;
+      if (line[0] === '+') {
+        lineMap[fileLineIndex] = diffLineIndex;
+      }
+    }
+  });
+
+  return lineMap;
+}
+
+function sendComment(user, repo, number, sha, filename, lineMap, message) {
+  if (!lineMap[message.line]) {
+    // Do not send messages on lines that did not change
+    return;
+  }
+
+  var opts = {
+    user,
+    repo,
+    number,
+    sha,
+    path: filename,
+    commit_id: sha,
+    body: message.message,
+    position: lineMap[message.line],
+  };
+  github.pullRequests.createComment(opts, function(error, res) {
+    if (error) {
+      console.log(error);
+      return;
+    }
+  });
+  console.log('Sending comment', opts);
+}
+
+function main(messages, user, repo, number) {
+  // No message, we don't need to do anything :)
+  if (Object.keys(messages).length === 0) {
+    return;
+  }
+
+  getShaFromPullRequest(user, repo, number, (sha) => {
+    getFilesFromCommit(user, repo, sha, (files) => {
+      files
+        .filter((file) => messages[file.filename])
+        .forEach((file) => {
+          var lineMap = getLineMapFromPatch(file.patch);
+          messages[file.filename].forEach((message) => {
+            sendComment(user, repo, number, sha, file.filename, lineMap, message);
+          });
+        });
+    });
+  });
+}
+
+var content = '';
+process.stdin.resume();
+process.stdin.on('data', function(buf) { content += buf.toString(); });
+process.stdin.on('end', function() {
+  var messages = {};
+
+  // Since we send a few http requests to setup the process, we don't want
+  // to run this file one time per code analysis tool. Instead, we write all
+  // the results in the same stdin stream.
+  // The format of this stream is
+  //
+  //   name-of-the-converter
+  //   {"json":"payload"}
+  //   name-of-the-other-converter
+  //   {"other": ["json", "payload"]}
+  //
+  // In order to generate such stream, here is a sample bash command:
+  //
+  //   cat <(echo eslint; npm run lint --silent -- --format=json; echo flow; flow --json) | node code-analysis-bot.js
+
+  var lines = content.trim().split('\n');
+  for (var i = 0; i < Math.ceil(lines.length / 2); ++i) {
+    var converter = converters[lines[i * 2]];
+    if (!converter) {
+      throw new Error('Unknown converter ' + lines[i * 2]);
+    }
+    var json;
+    try {
+      json = JSON.parse(lines[i * 2 + 1]);
+    } catch (e) {}
+
+    converter(messages, json);
+  }
+
+  // The paths are returned in absolute from code analysis tools but github works
+  // on paths relative from the root of the project. Doing the normalization here.
+  var pwd = path.resolve('.');
+  for (var absolutePath in messages) {
+    var relativePath = path.relative(pwd, absolutePath);
+    if (relativePath === absolutePath) {
+      continue;
+    }
+    messages[relativePath] = messages[absolutePath];
+    delete messages[absolutePath];
+  }
+
+  // TRAVIS_REPO_SLUG // 'facebook/react-native'
+  var user_repo = process.env.TRAVIS_REPO_SLUG.split('/');
+  var user = user_repo[0];
+  var repo = user_repo[1];
+  var number = process.env.TRAVIS_PULL_REQUEST;
+
+  // intentional lint warning to make sure that the bot is working :)
+  main(messages, user, repo, number)
+});

package.json

@@ -46,7 +46,7 @@
   ],
   "scripts": {
     "test": "NODE_ENV=test jest",
-    "lint": "eslint Examples/ Libraries/",
+    "lint": "eslint Examples/ Libraries/ bots/code-analysis-bot.js",
     "start": "/usr/bin/env bash -c './packager/packager.sh \"$@\" || true' --"
   },
   "bin": {
@@ -122,6 +122,7 @@
     "yeoman-generator": "^0.20.3"
   },
   "devDependencies": {
+    "github": "^0.2.4",
     "jest-cli": "0.7.1",
     "babel-eslint": "4.1.4",
     "eslint": "1.3.1",