Are there any projects that used node.js and closure-compiler (CC for short) together?
The official CC recommendation is to compile all code for an application together, but when I compile some simple node.js code which contains a require("./MyLib.js")
, that line is put directly into the output, but it doesn't make any sense in that context.
I see a few options:
js receives a CPU bound task: Whenever a heavy request comes to the event loop, Node. js would set all the CPU available to process it first, and then answer other requests queued. That results in slow processing and overall delay in the event loop, which is why Node. js is not recommended for heavy computation.
Node. js development has become very popular over the last four years and continues to stand the competition in 2022 making startups worldwide choose it over other available options.
js for CPU-intensive operations; in fact, using it for heavy computation will annul nearly all of its advantages. Where Node really shines is in building fast, scalable network applications, as it's capable of handling a huge number of simultaneous connections with high throughput, which equates to high scalability.
I have been using the Closure Compiler with Node for a project I haven't released yet. It has taken a bit of tooling, but it has helped catch many errors and has a pretty short edit-restart-test cycle.
First, I use plovr (which is a project that I created and maintain) in order to use the Closure Compiler, Library, and Templates together. I write my Node code in the style of the Closure Library, so each file defines its own class or collection of utilities (like goog.array
).
The next step is to create a bunch of externs files for the Node functions you want to use. I published some of these publicly at:
https://github.com/bolinfest/node-google-closure-latitude-experiment/tree/master/externs/node/v0.4.8
Though ultimately, I think that this should be a more community driven thing because there are a lot of functions to document. (It's also annoying because some Node functions have optional middle arguments rather than last arguments, making the type annotations complicated.) I haven't started this movement myself because it's possible that we could do some work with the Closure Complier to make this less awkward (see below).
Say you have created the externs file for the Node namespace http
. In my system, I have decided that anytime I need http
, I will include it via:
var http = require('http');
Though I do not include that require()
call in my code. Instead, I use the output-wrapper
feature of the Closure Compiler the prepend all of the require()
s at the start of the file, which when declared in plovr, in my current project looks like this:
"output-wrapper": [ // Because the server code depends on goog.net.Cookies, which references the // global variable "document" when instantiating goog.net.cookies, we must // supply a dummy global object for document. "var document = {};\n", "var bee = require('beeline');\n", "var crypto = require('crypto');\n", "var fs = require('fs');\n", "var http = require('http');\n", "var https = require('https');\n", "var mongodb = require('mongodb');\n", "var nodePath = require('path');\n", "var nodeUrl = require('url');\n", "var querystring = require('querystring');\n", "var SocketIo = require('socket.io');\n", "%output%" ],
In this way, my library code never calls Node's require()
, but the Compiler tolerates the uses of things like http
in my code because the Compiler recognizes them as externs. As they are not true externs, they have to be prepended as I described.
Ultimately, after talking about this on the discussion list, I think the better solution is to have a new type annotation for namespaces that would look something like:
goog.scope(function() { /** @type {~NodeHttpNamesapce} */ var http = require('http'); // Use http throughout. });
In this scenario, an externs file would define the NodeHttpNamespace
such that the Closure Compiler would be able to typecheck properties on it using the externs file. The difference here is that you could name the return value of require()
whatever you wanted because the type of http
would be this special namespace type. (Identifying a "jQuery namespace" for $
is a similar issue.) This approach would eliminate the need to name your local variables for Node namespaces consistently, and would eliminate the need for that giant output-wrapper
in the plovr config.
But that was a digression...once I have things set up as described above, I have a shell script that:
RAW
mode.node
on the file generated by plovr.Using RAW
mode results in a large concatenation of all the files (though it also takes care of translating Soy templates and even CoffeeScript to JavaScript). Admittedly, this makes debugging a pain because the line numbers are nonsense, but has been working well enough for me so far. All of the checks performed by the Closure Compiler have made it worth it.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With