json-parse-even-better-errors

WebJar for json-parse-even-better-errors

License

License

MIT
Categories

Categories

JSON Data
GroupId

GroupId

org.webjars.npm
ArtifactId

ArtifactId

json-parse-even-better-errors
Last Version

Last Version

2.3.1
Release Date

Release Date

Type

Type

jar
Description

Description

json-parse-even-better-errors
WebJar for json-parse-even-better-errors
Project URL

Project URL

https://www.webjars.org
Source Code Management

Source Code Management

https://github.com/npm/json-parse-even-better-errors

Download json-parse-even-better-errors

How to add to project

<!-- https://jarcasting.com/artifacts/org.webjars.npm/json-parse-even-better-errors/ -->
<dependency>
    <groupId>org.webjars.npm</groupId>
    <artifactId>json-parse-even-better-errors</artifactId>
    <version>2.3.1</version>
</dependency>
// https://jarcasting.com/artifacts/org.webjars.npm/json-parse-even-better-errors/
implementation 'org.webjars.npm:json-parse-even-better-errors:2.3.1'
// https://jarcasting.com/artifacts/org.webjars.npm/json-parse-even-better-errors/
implementation ("org.webjars.npm:json-parse-even-better-errors:2.3.1")
'org.webjars.npm:json-parse-even-better-errors:jar:2.3.1'
<dependency org="org.webjars.npm" name="json-parse-even-better-errors" rev="2.3.1">
  <artifact name="json-parse-even-better-errors" type="jar" />
</dependency>
@Grapes(
@Grab(group='org.webjars.npm', module='json-parse-even-better-errors', version='2.3.1')
)
libraryDependencies += "org.webjars.npm" % "json-parse-even-better-errors" % "2.3.1"
[org.webjars.npm/json-parse-even-better-errors "2.3.1"]

Dependencies

There are no dependencies for this project. It is a standalone project that does not depend on any other jars.

Project Modules

There are no modules declared in this project.

json-parse-even-better-errors

json-parse-even-better-errors is a Node.js library for getting nicer errors out of JSON.parse(), including context and position of the parse errors.

It also preserves the newline and indentation styles of the JSON data, by putting them in the object or array in the Symbol.for('indent') and Symbol.for('newline') properties.

Install

$ npm install --save json-parse-even-better-errors

Table of Contents

Example

const parseJson = require('json-parse-even-better-errors')

parseJson('"foo"') // returns the string 'foo'
parseJson('garbage') // more useful error message
parseJson.noExceptions('garbage') // returns undefined

Features

  • Like JSON.parse, but the errors are better.
  • Strips a leading byte-order-mark that you sometimes get reading files.
  • Has a noExceptions method that returns undefined rather than throwing.
  • Attaches the newline character(s) used to the Symbol.for('newline') property on objects and arrays.
  • Attaches the indentation character(s) used to the Symbol.for('indent') property on objects and arrays.

Indentation

To preserve indentation when the file is saved back to disk, use data[Symbol.for('indent')] as the third argument to JSON.stringify, and if you want to preserve windows \r\n newlines, replace the \n chars in the string with data[Symbol.for('newline')].

For example:

const txt = await readFile('./package.json', 'utf8')
const data = parseJsonEvenBetterErrors(txt)
const indent = Symbol.for('indent')
const newline = Symbol.for('newline')
// .. do some stuff to the data ..
const string = JSON.stringify(data, null, data[indent]) + '\n'
const eolFixed = data[newline] === '\n' ? string
  : string.replace(/\n/g, data[newline])
await writeFile('./package.json', eolFixed)

Indentation is determined by looking at the whitespace between the initial { and [ and the character that follows it. If you have lots of weird inconsistent indentation, then it won't track that or give you any way to preserve it. Whether this is a bug or a feature is debatable ;)

API

parse(txt, reviver = null, context = 20)

Works just like JSON.parse, but will include a bit more information when an error happens, and attaches a Symbol.for('indent') and Symbol.for('newline') on objects and arrays. This throws a JSONParseError.

parse.noExceptions(txt, reviver = null)

Works just like JSON.parse, but will return undefined rather than throwing an error.

class JSONParseError(er, text, context = 20, caller = null)

Extends the JavaScript SyntaxError class to parse the message and provide better metadata.

Pass in the error thrown by the built-in JSON.parse, and the text being parsed, and it'll parse out the bits needed to be helpful.

context defaults to 20.

Set a caller function to trim internal implementation details out of the stack trace. When calling parseJson, this is set to the parseJson function. If not set, then the constructor defaults to itself, so the stack trace will point to the spot where you call new JSONParseError.

org.webjars.npm

npm

node package manager

Versions

Version
2.3.1
2.3.0
2.0.1