Tools

• module bundler : creates a single file from multiple files by creating a dependency graph. Most popular are Vite and Webpack
• Transpiler : converts code from other languages to ones browser understands. e.g. Babel
• Task runner: To automate different parts of the build process like testing, linting, compiling etc.
• Version control system : software tool that help track changes to source code over time and revert back when required.
• Git : a distributed version control tool. It records changes in a project as snapshots in a database called repository
• Test runners : tools that execute a pre-defined test script and auto-generate results. e.g. Jest
• Code splitting : practice of breaking up application into smaller pieces that can be loaded on demand.

GIT

• has two main data structures - object store & index, stored in .git folder
• Git objects represent a data structure and have a unique hash-id. Types
  • Blobs (file structures)
  • Trees ( directory structure)
    • tree-ish is anything that ultimately leads to a tree object. e.g. branch, tag
    • commit-ish (type of tree-ishes) e.g. HEAD, sha-1 hash
    • combined : tree-ish:path e.g. main:assets/hello.js
• A branch is pointer to last commit made on branch. Internally, it's a file that contains sha-1 checksum of last commit
• new branch -> new copy
• HEAD is pointer to current local branch ; when it points to a specific commit -> detached

2 ways to integrate branches

• merge : combine end-points and point to it.
  • fast-forward: move main branch's tip forward onto feat tip
  • 2 parent: new commit is created (merge commit)
• rebase : replay all commits in a particular branch over a different branch