eth-json-rpc-errors

Errors for the Ethereum JSON RPC and Ethereum Provider, and making unknown errors compliant with either spec.

Basic Usage

1import { ethErrors } from 'eth-json-rpc-errors'
2
3throw ethErrors.provider.unauthorized()
4// or
5throw ethErrors.provider.unauthorized('my custom message')

Supported Errors

• Ethereum JSON RPC
  • Per EIP 1474
    • This includes all JSON RPC 2.0 errors
• Ethereum Provider errors
  • Per EIP 1193
    • Does not yet support CloseEvent errors or status codes.

Usage

Installation: npm install eth-json-rpc-errors or yarn add eth-json-rpc-errors

Import using ES6 syntax (no default export) or Node require.

Errors API

1import { ethErrors } from 'eth-json-rpc-errors'
2
3// Ethereum RPC errors are namespaced under "ethErrors.rpc"
4response.error = ethErrors.rpc.methodNotFound({
5  message: optionalCustomMessage, data: optionalData
6})
7
8// ETH JSON RPC errors namespaced under ethErrors.provider
9response.error = ethErrors.provider.unauthorized({
10  message: optionalCustomMessage, data: optionalData
11})
12
13// each error getter takes a single "opts" argument
14// for most errors, this can be replaced with a single string, which becomes
15// the error message
16response.error = ethErrors.provider.unauthorized(customMessage)
17
18// if an error getter accepts a single string, all arguments can be omitted
19response.error = ethErrors.provider.unauthorized()
20response.error = ethErrors.provider.unauthorized({})
21
22// omitting the message will produce an error with a default message per
23// the relevant spec
24
25// omitting the data argument will produce an error without a
26// "data" property
27
28// the JSON RPC 2.0 server error requires a valid code
29response.error = ethErrors.rpc.server({
30  code: -32031
31})
32
33// custom Ethereum Provider errors require a valid code and message
34// valid codes are integers i such that: 1000 <= i <= 4999
35response.error = ethErrors.provider.custom({
36  code: 1001, message: 'foo'
37})

Parsing Unknown Errors

1// this is useful for ensuring your errors are standardized
2import { serializeError } from 'eth-json-rpc-errors'
3
4// if the argument is not a valid error per any supported spec,
5// it will be added as error.data.originalError
6response.error = serializeError(maybeAnError)
7
8// you can add a custom fallback error code and message if desired
9const fallbackError = { code: 4999, message: 'My custom error.' }
10response.error = serializeError(maybeAnError, fallbackError)
11
12// Note: if the original error has a "message" property, it will take
13// precedence over the fallback error's message
14
15// the default fallback is:
16{
17  code: -32603,
18  message: 'Internal JSON-RPC error.'
19}

Other Exports

1/**
2 * TypeScript interfaces
3 */
4import {
5  // these describe to the corresponding exports from index.js
6  IEthErrors, IEthereumRpcError, IEthereumProviderError, ISerializeError,
7  // these describe the options argument to error getters in ethErrors
8  IErrorOptions, IRpcServerErrorOptions, IProviderCustomErrorOptions
9} from 'eth-json-rpc-errors/@types'
10
11/**
12 * Classes
13 */
14import { EthereumRpcError, EthereumProviderError } from 'eth-json-rpc-errors'
15
16/**
17 * getMessageFromCode & ERROR_CODES
18 */
19import { getMessageFromCode, ERROR_CODES } from 'eth-json-rpc-errors'
20
21// get the default message string for the given code, or a fallback message if
22// no message exists for the given code
23const message1 = getMessageFromCode(someCode)
24
25// you can specify your own fallback message
26const message2 = getMessageFromCode(someCode, myFallback)
27// it can be anything, use at your own peril
28const message3 = getMessageFromCode(someCode, null)
29
30// {
31//   jsonRpc: { [errorName]: code, ... },
32//   eth: { [errorName]: code, ... },
33// }
34const code1 = ERROR_CODES.rpc.parse
35const code2 = ERROR_CODES.provider.userRejectedRequest
36
37// all codes in ERROR_CODES have default messages
38const message4 = getMessageFromCode(code1)
39const message5 = getMessageFromCode(code2)

License

MIT