I am getting the following error running the sample code.
My Node version is v10.5.0 and npm 6.1.0

(function (exports, require, module, __filename, __dirname) { import { OaiPmh } from 'oai-pmh'
^

SyntaxError: Unexpected token {
at new Script (vm.js:74:7)
at createScript (vm.js:246:10)
at Object.runInThisContext (vm.js:298:10)
at Module._compile (internal/modules/cjs/loader.js:670:28)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
at Module.load (internal/modules/cjs/loader.js:612:32)
at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
at Function.Module._load (internal/modules/cjs/loader.js:543:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:744:10)
at startup (internal/bootstrap/node.js:240:19)

In such cases the servers responds with Error: Unexpected status code 403 (expected 200).

How to reproduce:

./oai-pmh list-records -p oai_dc "http://arca.igc.gulbenkian.pt/oaiextended/request"

How to fix it

Add the following header to every request made:

  options.headers = {
        'User-Agent': 'request'
      };

Can I use an array like: ['cs', 'stat'] to 'set' param when call listRecords function?

From this script

import { OaiPmh } from 'oai-pmh'

async function main () {
const oaiPmh = new OaiPmh('http://www.culturaitalia.it/oaiProviderCI/OAIHandler')
const identifierIterator = oaiPmh.getRecord({
metadataPrefix: 'oai_dc',
identifier:'oai:culturaitalia.it:oai:www.michael-culture.it:pub-it/dcollection/IT-DC-e555496e'
})
for await (const identifier of identifierIterator) {
console.log(identifier)
}
}

main().catch(console.error)

Running the command getRecord I got this error(s)

TypeError: identifierIterator is not async iterable
at main (/Users/matteo/vsProject/OAI-PMH/richiesta_terminale.js:9:34)
at Object. (/Users/matteo/vsProject/OAI-PMH/richiesta_terminale.js:14:1)
at Cl (/Users/matteo/node_modules/esm/esm.js:1:210825)
at Object.run (/Users/matteo/node_modules/esm/esm.js:1:209532)
at Object. (/Users/matteo/vsProject/OAI-PMH/richiesta_terminale.js:1:86)
at Object. (/Users/matteo/node_modules/esm/esm.js:1:223819)
at eu (/Users/matteo/node_modules/esm/esm.js:1:217938)
at /Users/matteo/node_modules/esm/esm.js:1:219136
at ou (/Users/matteo/node_modules/esm/esm.js:1:219372)
at Object.g (/Users/matteo/node_modules/esm/esm.js:1:230080)
(node:23762) UnhandledPromiseRejectionWarning: OaiPmhError: OAI-PMH provider returned an error: The request includes illegal arguments, is missing required arguments, includes a repeated argument, or values for arguments have an illegal syntax.
at new OaiPmhError (/Users/matteo/node_modules/oai-pmh/src/errors.js:8:11)
at parseOaiPmhXml (/Users/matteo/node_modules/oai-pmh/src/oai-pmh-xml.js:24:11)
at process._tickCallback (internal/process/next_tick.js:68:7)
(node:23762) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)
(node:23762) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Perhaps we want

      explicitArray: false,
      normalize: true,
      trim: true,

in xml2js.

How to reproduce.

oai-pmh list-sets https://oai.mikromarc.no/OAI/mic 

The reason is that the result will not be an array because of the option to parseString explicitArray: false,. This results in that you can't iterate on it.

There is two ways to solve this in oai-pmh-list.js

Concat returned item into an array in both locations.

// Line 33
for (const item of [].concat(initialResult[field])) {

// Line 49
for (const item of [].concat(result[field])) {

A alternative is to check if the returned object if it is iterable.

if (typeof initialResult[field][Symbol.iterator] === 'function') {
  for (const item of initialResult[field]) {
    yield item
  }
}
else {
  yield  initialResult[field]
}

if (typeof result[field][Symbol.iterator] === 'function') {
  for (const item of result[field]) {
    yield item
  }
}
else {
  yield  result[field]
}

(node:17832) UnhandledPromiseRejectionWarning: Error: OAI-PMH provider returned an error: ListRecords verb must receive the metadataPrefix parameter
    at new OaiPmhError (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/oai-pmh/dist/utils.js:40:11)
    at _parseOaiPmhXml (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/oai-pmh/dist/utils.js:66:11)
    at _parseOaiPmhXml.next (<anonymous>)
    at onFulfilled (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/co/index.js:65:19)
    at tryCatcher (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/util.js:16:23)
    at Promise._settlePromiseFromHandler (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:512:31)
    at Promise._settlePromise (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:569:18)
    at Promise._settlePromiseCtx (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:606:10)
    at Async._drainQueue (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:138:12)
    at Async._drainQueues (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:143:10)
    at Immediate.Async.drainQueues [as _onImmediate] (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:17:14)
    at runCallback (timers.js:794:20)
    at tryOnImmediate (timers.js:752:5)
    at processImmediate [as _immediateCallback] (timers.js:729:5)
(node:17832) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 3)
(node:17832) UnhandledPromiseRejectionWarning: Error: OAI-PMH provider returned an error: ListRecords verb must receive the metadataPrefix parameter
    at new OaiPmhError (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/oai-pmh/dist/utils.js:40:11)
    at _parseOaiPmhXml (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/oai-pmh/dist/utils.js:66:11)
    at _parseOaiPmhXml.next (<anonymous>)
    at onFulfilled (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/co/index.js:65:19)
    at tryCatcher (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/util.js:16:23)
    at Promise._settlePromiseFromHandler (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:512:31)
    at Promise._settlePromise (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:569:18)
    at Promise._settlePromiseCtx (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/promise.js:606:10)
    at Async._drainQueue (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:138:12)
    at Async._drainQueues (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:143:10)
    at Immediate.Async.drainQueues [as _onImmediate] (/Users/mferreira/git/ipca-pw/oai-pmh-harvester/node_modules/bluebird/js/release/async.js:17:14)
    at runCallback (timers.js:794:20)
    at tryOnImmediate (timers.js:752:5)
    at processImmediate [as _immediateCallback] (timers.js:729:5)
(node:17832) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 4)

When trying to harvest "http://arca.igc.gulbenkian.pt/oaiextended/request"

Do you know why is getting me this compiling error?
I'm just using the code in the example
I run using "node -r esm" like in the example and it run perfectly
**`import { OaiPmh } from 'oai-pmh'

async function main () {
const oaiPmh = new OaiPmh('http://export.arxiv.org/oai2')
const identifierIterator = oaiPmh.listIdentifiers({
metadataPrefix: 'oai_dc',
from: '2015-01-01',
until: '2015-01-04'
})
for await (const identifier of identifierIterator) {
console.log(identifier)
}
}

main().catch(console.error)`**
but when i tried to use in normal code compilng an app it gets me the following error:

Hi,

Could you update the library example to make easier for students to take the code and make it run straight away? Or, at least, provide a way of running it. Does it require babel to run?

Cheers.

When I tried to list records (or identifiers), I got

Error: OAI-PMH provider returned an error: The request is missing required arguments.

after the first batch. Testing a little bit confirmed that the error was caused by the resumption token being null. When I had a look at the code to try to understand why, I was puzzled by line 39 in index.js:

          resumptionToken: self.currentResult.resumptionToken._,

If I remove ._ it sends the resumption token correctly. But since the ._ has been there for so long, I assume it must have some intention? I'm only working with Node occasionally, so I'm not able to figure out what, though :)

To reproduce: With Node 8.6.0:

oai-pmh list-records -p marc21 -s oai_komplett http://bibsys-k.alma.exlibrisgroup.com/view/oai/47BIBSYS_UBO/request

Can you give me example?.