parcel build is the command that turns a Parcel project into deployable static assets. Unlike the development server, which watches files and serves them with hot module replacement, the build command runs once, applies every production optimization Parcel knows about, writes the result to disk, and exits. The output lands in a directory called dist…
Parcel’s development server is started by the default parcel command, which is a shortcut for parcel serve. It listens on http://localhost:1234 by default, and if port 1234 is occupied, it falls back to another port automatically . The server rebuilds the changed files as you edit and pushes the updates to the browser, so the…
Parcel project setup is deliberately minimal. There is no configuration file to write and no directory structure to obey. The setup consists of one HTML file, one or more source files referenced from it, and a package.json that points Parcel at the HTML entry. The previous chapter covered the CLI commands; this chapter covers the…
Parcel is distributed as a single npm package named parcel, installed as a development dependency. The package includes the CLI and the default configuration, so the installation is one command and the first build works without any additional setup. The previous chapter covered the zero-config philosophy and the asset graph; this chapter covers the installation…
Parcel is a web application bundler built around a single promise: it works out of the box. Where webpack requires a configuration file to understand what to do with a .ts file, a CSS import, or an image reference, Parcel infers the transformation pipeline from the file itself and the project’s existing configuration files. The…
The –format flag determines the module syntax that esbuild writes into the output file. It is not a cosmetic choice: the format decides whether the output uses require() and module.exports, import and export, or a self-executing function that attaches its exports to a global variable. The previous chapter covered the graph traversal and the tree…
The –bundle flag is the switch that turns esbuild from a single-file transpiler into a graph processor. When it is present, esbuild reads the entry point, parses its imports, resolves each import to a file on disk or a package in node_modules, parses that file, and repeats the process until the entire reachable graph has…
The esbuild CLI has two distinct modes that are easy to conflate. The –bundle flag walks the import graph, merges every dependency into one file, and resolves the bare specifiers against node_modules. Without –bundle, esbuild operates as a transpiler: it reads one file, strips the TypeScript or JSX syntax, optionally lowers the JavaScript target, and…
esbuild is not a pure JavaScript package. It is a Go binary that is distributed through npm as a set of platform-specific optional dependencies, and the installation is the step where the package manager selects the one binary that matches the current operating system and CPU architecture. The previous chapter covered the Go-based architecture that…
esbuild is a JavaScript and CSS bundler and minifier written in Go, and its reason for existing is stated plainly by its author: “Our current build tools for the web are 10-100x slower than they could be” . The project was created by Evan Wallace to demonstrate that the build tool performance ceiling was not…