vfile-message

What is vfile-message?

The vfile-message npm package is designed for creating and managing virtual file messages, such as warnings and errors, in a standardized format. It is commonly used in file processing pipelines to report issues found during the processing of files. These messages can include details such as the position of the issue within the file, the rule that was violated, and a human-readable message describing the problem.

What are vfile-message's main functionalities?

Creating a new message

This code demonstrates how to create a new vfile message. The message includes a human-readable string, a position object indicating where in the file the message applies, and an optional error code.

{"const VFileMessage = require('vfile-message');\nconst message = new VFileMessage('This is an error message', {line: 10, column: 5}, 'error-code');\nconsole.log(message);"}

Associating a message with a file

This example shows how to create a vfile message and associate it with a vfile. The message is pushed into the file's `messages` array, allowing multiple messages to be associated with a single file.

{"const vfile = require('vfile');\nconst VFileMessage = require('vfile-message');\nconst file = vfile();\nconst error = new VFileMessage('Invalid syntax', {line: 2, column: 10}, 'syntax-error');\nfile.messages.push(error);\nconsole.log(file.messages);"}

Other packages similar to vfile-message

eslint

ESLint is a tool for identifying and reporting on patterns found in ECMAScript/JavaScript code, making it somewhat similar to vfile-message in its ability to report errors and warnings. However, ESLint is more focused on linting JavaScript code according to customizable coding standards, whereas vfile-message is more generic and can be used with any type of file.

chalk

Chalk is a package for styling terminal text. While not directly similar to vfile-message in functionality, it is often used alongside vfile-message and other reporting tools to colorize messages (errors, warnings) for better visibility in the console. Chalk does not create or manage messages but enhances the presentation of messages created by packages like vfile-message.

remark-lint

Remark-lint is a markdown code style linter that is part of the unified.js ecosystem, similar to vfile-message which is also often used in the unified ecosystem for handling messages. Remark-lint focuses specifically on linting Markdown files according to a set of rules, generating messages (warnings, errors) similar to those created by vfile-message, but with a focus on Markdown content.

README

vfile-message

Create vfile messages.

Install

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

npm:

npm install vfile-message

Use

import {VFileMessage} from 'vfile-message'

var message = new VFileMessage(
  '`braavo` is misspelt; did you mean `bravo`?',
  {line: 1, column: 8},
  'spell:typo'
)

console.log(message)

Yields:

[1:8: `braavo` is misspelt; did you mean `bravo`?] {
  reason: '`braavo` is misspelt; did you mean `bravo`?',
  line: 1,
  column: 8,
  source: 'spell',
  ruleId: 'typo',
  position: {start: {line: 1, column: 8}, end: {line: null, column: null}}
}

API

This package exports the following identifiers: VFileMessage. There is no default export.

VFileMessage(reason[, place][, origin])

Constructor of a message for reason at place from origin. When an error is passed in as reason, copies the stack.

Parameters

reason

Reason for message (string or Error). Uses the stack and message of the error if given.

place

Place at which the message occurred in a file (Node, Position, or Point, optional).

origin

Place in code the message originates from (string, optional).

Can either be the ruleId ('rule'), or a string with both a source and a ruleId delimited with a colon ('source:rule').

Extends

Error.

Returns

An instance of itself.

Properties

reason

Reason for message (string).

fatal

If true, marks associated file as no longer processable (boolean?). If false, necessitates a (potential) change. The value can also be null or undefined.

line

Starting line of error (number?).

column

Starting column of error (number?).

position

Full range information, when available (Position). Has start and end properties, both set to an object with line and column, set to number?.

source

Namespace of message (string?).

ruleId

Category of message (string?).

stack

Stack of message (string?).

Custom properties

It’s OK to store custom data directly on the VFileMessage, some of those are handled by utilities.

actual

You can use this to specify the source value that’s being reported, which is deemed incorrect.

expected

You can use this to suggest values that should be used instead of actual, one or more values that are deemed as acceptable.

file

You may add a file property with a path of a file (used throughout the VFile ecosystem).

note

You may add a note property with a long form description of the message (supported by vfile-reporter).

url

You may add a url property with a link to documentation for the message.

Contribute

See contributing.md in vfile/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer