Refactoring: Try-Catch for Variable Assignment in JS

Hammad Malik — Tue, 05 May 2020 22:22:06 +0000

I was refactoring an Express application when I came across a curious bit of code:

let email;

try {
  email = req.body.email;
} catch (err) {}

I believe this code is attempting to throw an error if the "name" property is missing in req.body – if req.body.name did not exist the assignment would cause an error and it would stop execution of the rest of the code.

However, that's not what happens! req.body.email is undefined, so it is perfectly possible to assign undefined as the value for the name variable.

I think hasOwnProperty is more reliable way to make sure req.body container an email:

if (!req.body.hasOwnProperty("name")) {
  const err = new ReferenceError("no name in request body.");
  throw err;
}

const {email} = req.body

PS: For Express specifically, I'm interested in learning more about validating the req.body using JSON Schema or Joi.

Something I Learned Today: Using `git diff` and `git log -u` to see changes in a file between commit

Hammad Malik — Mon, 20 Aug 2018 16:15:07 +0000

Problem

I have to make changes to a template file, but on my current branch I was working with the database. So I want to make a new branch just for the Template updates, but need to double check that I didn’t make a change to that file in the commit history of the separate branch

Resources

Findings

<commit_0>..<commit_1> is shorthand for checking the differences between two commits, not to be confused with...
<commit_0>...<commit_1> - with three dots - which also covers all the commits between the two commits inclusively. Two dots simply compares one with another.
And you can also exclude one of the commit references, and it will fall back as if HEAD were used as the value instead. Oh, and you can just use HEAD

Further Research