Boa CLI

Boa CLI is Boa's REPL implementation to execute JavaScript directly from your CLI.

Installation

boa_cli can be installed directly via Cargo.

shell

    cargo install boa_cli

Usage

Once installed, your good to go!

To execute some JavaScript source code, navigate to the directory of your choice and type:

shell

    boa test.js

Or if you'd like to use Boa's REPL, simply type:

shell

boa

You can also pipe JavaScript into Boa:

shell

    echo 'console.log(1 + 2)' | boa
    cat script.js | boa
    boa < script.js

CLI Options

txt

Usage: boa [OPTIONS] [FILE]...

Arguments:
  [FILE]...  The JavaScript file(s) to be evaluated

Options:
      --strict                        Run in strict mode
  -a, --dump-ast [<FORMAT>]           Dump the AST to stdout with the given format [possible values: debug, json, json-pretty]
  -t, --trace                         Dump the AST to stdout with the given format
      --vi                            Use vi mode in the REPL
  -O, --optimize                      Enable bytecode compiler optimizations
      --optimizer-statistics           Print optimizer statistics (requires -O)
      --flowgraph [<FORMAT>]          Generate instruction flowgraph. Default is Graphviz [possible values: graphviz, mermaid]
      --flowgraph-direction <FORMAT>  Specifies the direction of the flowgraph. Default is top-top-bottom [possible values: top-to-bottom, bottom-to-top, left-to-right, right-to-left]
      --debug-object                  Inject debugging object `$boa`
      --test262-object                Inject the test262 host object `$262`
  -m, --module                        Treats the input files as modules
  -r, --root <ROOT>                   Root path from where the module resolver will try to load the modules [default: .]
  -e, --expression <EXPR>             Execute a JavaScript expression then exit
  -q, --quiet                         Suppress the welcome banner when starting the REPL
  -h, --help                          Print help (see more with '--help')
  -V, --version                       Print version

REPL Commands

When running the interactive REPL (boa with no file arguments), the following dot-commands are available:

Command	Description
`.help`	Show available REPL commands
`.exit`	Exit the REPL
`.clear`	Clear the terminal screen
`.load <file>`	Load and evaluate a JavaScript file

You can also press Ctrl+C to abort the current expression, or Ctrl+D to exit.

Features

Boa's CLI currently has a variety of features (as listed in Options).

Features include:

Implemented runtime features (please note that only Console is currently implemented)
AST Visibility: View the compiled Boa AST (--dump-ast)
Tracing: Enabling a vm tracing when executing any JavaScript
Flowgraphs: View a generated (with various provided options)
Debugging: Boa's CLI comes with an implemented $boa debug object with various functionality (see documentation).

Have an idea for a feature? Feel free to submit an issue and/or contribute!