core-error-predicates

npm install core-error-predicates

Error predicate functions for operational errors thrown by node core.
Predicate functions take an error object as argument and return true if the error object matches. This useful for instance when using bluebird catch filters or in the future when the JavaScript catch clauses will be able to take filter/predicate function parameters.
Example using bluebird:

require("core-error-predicates").globalize();
fs.readFileAsync("test.txt", "utf8").then(function(contents) {
    console.log("file contents:", contents);
})
.catch(FileNotFoundError, function(e) {
    console.log("file test.txt does not exist");
})
.catch(FileAccessError, function(e) {
    console.log("no permissions to access test.txt");
});

The module exports various error predicates and the .globalize() method.
The .globalize() method makes all the predicate functions available in global scope for convenience. If the name is already taken for a predicate in global scope, it will not be overwritten.
Predicates can be turned into instances of their error types by using the new operator:

try {
  throw new FileNotFoundError("A file was not found!");
}
catch (e) {
  assert(FileNotFoundError(e) === true);
}

Error predicates

- FileNotFoundError - FileAccessError - EOFError - UnknownHostError - SocketError - ProtocolError - FileSystemError - ConnectError - BindError - AddressNotFoundError - NetworkError - SSLError

FileNotFoundError

When the error's code matches one of:
- ENOENT

FileAccessError

When the error's code matches one of:
- EACCES - EPERM

EOFError

When the error's code matches one of:
- EOF

UnknownHostError

When the error's code matches one of:
- EADDRINFO

SocketError

When the error's code matches one of:
- EISCONN - ENOTCONN - ENOTSOCK - ENOTSUP - EPROTOTYPE - EAIFAMNOSUPPORT - EAISERVICE

ProtocolError

When the error's code matches one of:

• EPROTO
• EPROTONOSUPPORT
• EPROTOTYPE

FileSystemError

When the error's code matches one of:
- EBUSY - ENOENT - EOF - EACCES - EAGAIN - EBADF - EMFILE - ENOTDIR - EISDIR - EEXIST - ENAMETOOLONG - EPERM - ELOOP - ENOTEMPTY - ENOSPC - EIO - EROFS - ENODEV - ESPIPE - ECANCELED - ENFILE - EXDEV

ConnectError

When the error's code matches one of:
- ECONNABORTED - ECONNREFUSED - ECONNRESET - ETIMEDOUT

BindError

When the error's code matches one of:
- EADDRNOTAVAIL

AddressNotFoundError

When the error's code matches one of:
- ENOTFOUND

NetworkError

When the error's code matches one of:
- EADDRINFO - EADDRNOTAVAIL - EAFNOSUPPORT - EALREADY - ECONNABORTED - ECONNREFUSED - ECONNRESET - EDESTADDRREQ - EHOSTUNREACH - EISCONN - EMSGSIZE - ENETDOWN - ENETUNREACH - ENONET - ENOTCONN - ENOTSOCK - ENOTSUP - EPIPE - EPROTO - EPROTONOSUPPORT - EPROTOTYPE - ETIMEDOUT - EAIFAMNOSUPPORT - EAISERVICE - EAISOCKTYPE - ESHUTDOWN - ENOTFOUND

SSLError

When the error's message begins with "SSL Error:".The MIT License (MIT)
Copyright (c) 2015 Petka Antonov
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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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