Quick Tutorials

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Song Zheng edited this page Jan 30, 2022 · 7 revisions

Introduction

This page serves as a list of code samples to help you navigate certain concepts. When a pull request introduces a new concept, add it to this list!

Test

Mocking - sometimes you may not want libraries to be run during your tests. To auto mock out libraries, you just have to put the module-name.js into the __mocks__ folder. code sample for auto mocking.

Database

Prisma

If you want to create, update, or destroy a table, here are the steps:
- Edit prisma.schema file
- Run prisma migrate dev on the terminal.
- Sample PR for adding a table, Sample PR for updating a table

Postgres

Dump (backups): pg_dump -h hostIP databaseName > ~/feb28-2022-c0d3_prod.sql
Connect: psql -U dbuser -h hostIP databaseName

Sequelize

Promise.all vs Includes - When implementing session query, we had to decide between:

(40ms) using Promise.all(....) for 3 queries
(60ms) using 3 sequential queries
(138ms) using 1 query

We all thought using 1 queries would be the fastest, so it turned out to be the slowest.