index.js

"use strict";
var t0 = Date.now();

var express = require("express"),
    bl = require("bl"),
    labelModel = require('./lib/label-model'),
    metadata = require('./lib/metadata'),
    comment = require('./lib/comment'),
    rmReviewable = require('./lib/rm-reviewable'),
    github = require('./lib/github'),
    checkRequest = require('./lib/check-request'),
    isProcessed = require('./lib/is-processed'),
    q = require('q');
    
function promise(value) {
    var deferred = q.defer();
    deferred.resolve(value);
    return deferred.promise;
}

function waitFor(ms) {
    var deferred = q.defer();
    setTimeout(function() { deferred.resolve(); }, ms);
    return deferred.promise;
}

var app = module.exports = express();

function logArgs() {
    var args = arguments;
    process.nextTick(function() {
        console.log.apply(console, args);
    });
}

function funkLogMsg(num, msg) {
    return function() { logArgs("#" + num + ": " + msg); };
}

function funkLogErr(num, msg) {
    return function(err) { logArgs("#" + num + ": " + msg + "\n", err); };
}

function removeReviewableBanner(n, metadata) {
    return rmReviewable(n, metadata).then(
        funkLogMsg(n, "Removed Reviewable banner."),
        funkLogErr(n, "Error when attempting to remove Reviewable banner.")
    );
}

function getPullRequest(n, body) {
    if (body.pull_request) {
        return promise(body.pull_request);
    }
    return github.get("/repos/:owner/:repo/pulls/:number", { number: n })
}

var currentlyRunning = {};

app.post('/github-hook', function (req, res, next) {
	req.pipe(bl(function (err, body) {
    	if (err) {
        	logArgs(err.message);
		} else if (process.env.NODE_ENV != 'production' || checkRequest(body, req.headers["x-hub-signature"], process.env.GITHUB_SECRET)) {
		    res.send(new Date().toISOString());
            
            // FILTER ALL THE THINGS
            try {
    	        body = JSON.parse(body);
            } catch(e) {
                return;
            }
            if (!body) return;
            if (body.sender && body.sender.login == "wpt-pr-bot") return;
            if (!body.pull_request && (body.issue && !body.issue.pull_request)) return;
            // END FILTERNG //
            
            var action = body.action;
            var isComment = !!body.comment;
            var issue = body.pull_request || body.issue;
            var n = issue.number;
            var u = (issue.user && issue.user.login) || null;
            var content = issue.body || "";
            if (!isComment && action == "edited") {
                if (body.pull_request.merged) return; // we know .pullrequest is available because it's not a comment.
                logArgs("#" + n, "pull request edited");
	            metadata(n, u, content).then(function(metadata) {
                    return removeReviewableBanner(n, metadata);
                });
            } else if (action == "opened" || action == "synchronize" || (isComment && action == "created")) {
                if (n in currentlyRunning) {
                    logArgs("#" + n + " is already being processed.");
                    return;
                }
                currentlyRunning[n] = true;
                logArgs("#" + n, isComment ? "comment" : "pull request", action);
                
                waitFor(5 * 1000).then(function() { // Avoid race condition
                    return getPullRequest(n, body);
                }).then(function(pull_request) {
                    if (pull_request.merged) return;
                    return metadata(n, u, content).then(function(metadata) {
                        logArgs(metadata);
                        return labelModel.post(n, metadata.labels).then(
                            funkLogMsg(n, "Added missing LABELS if any."),
                            funkLogErr(n, "Something went wrong while adding missing LABELS.")
                        ).then(function() {
                            return comment(n, metadata);
                        }).then(
                            funkLogMsg(n, "Added missing REVIEWERS if any."),
                            funkLogErr(n, "Something went wrong while adding missing REVIEWERS.")
                        ).then(function() {
                            return removeReviewableBanner(n, metadata);
                        });
                    });
                }).then(function() {
                    delete currentlyRunning[n];
                }, function(err) {
                    delete currentlyRunning[n];
                    funkLogErr(n, "THIS SHOULDN'T EVER HAPPEN")(err);
                });
            } else {
                logArgs("#" + n + ": not handled.", "action:", action, "isComment:", isComment);
            }
        } else {
            logArgs("Unverified request", req);
        }
    }));
});

var port = process.env.PORT || 5000;
app.listen(port, function() {
    console.log("Express server listening on port %d in %s mode", port, app.settings.env);
    console.log("App started in", (Date.now() - t0) + "ms.");
});