@metamask/providers
Version:
A JavaScript Ethereum provider that connects to the wallet over a stream
83 lines • 3.83 kB
JavaScript
import { announceWallet } from "./CAIP294.mjs";
import { announceProvider as announceEip6963Provider } from "./EIP6963.mjs";
import { getBuildType } from "./extension-provider/createExternalExtensionProvider.mjs";
import { MetaMaskInpageProvider } from "./MetaMaskInpageProvider.mjs";
import { shimWeb3 } from "./shimWeb3.mjs";
/**
* Initializes a MetaMaskInpageProvider and (optionally) assigns it as window.ethereum.
*
* @param options - An options bag.
* @param options.connectionStream - A Node.js stream.
* @param options.maxEventListeners - The maximum number of event listeners.
* @param options.providerInfo - The EIP-6963 provider info / CAIP-294 wallet data that should be announced if set.
* @param options.shouldSendMetadata - Whether the provider should send page metadata.
* @param options.shouldSetOnWindow - Whether the provider should be set as window.ethereum.
* @param options.shouldShimWeb3 - Whether a window.web3 shim should be injected.
* @param options.logger - The logging API to use. Default: `console`.
* @returns The initialized provider (whether set or not).
*/
export function initializeProvider({ connectionStream, logger = console, maxEventListeners = 100, providerInfo, shouldSendMetadata = true, shouldSetOnWindow = true, shouldShimWeb3 = false, }) {
const provider = new MetaMaskInpageProvider(connectionStream, {
logger,
maxEventListeners,
shouldSendMetadata,
});
const proxiedProvider = new Proxy(provider, {
// some common libraries, e.g. web3@1.x, mess with our API
deleteProperty: () => true,
// fix issue with Proxy unable to access private variables from getters
// https://stackoverflow.com/a/73051482
get(target, propName) {
return target[propName];
},
});
if (providerInfo) {
announceEip6963Provider({
info: providerInfo,
provider: proxiedProvider,
});
// eslint-disable-next-line no-void
void announceCaip294WalletData(provider, providerInfo);
}
if (shouldSetOnWindow) {
setGlobalProvider(proxiedProvider);
}
if (shouldShimWeb3) {
shimWeb3(proxiedProvider, logger);
}
return proxiedProvider;
}
/**
* Sets the given provider instance as window.ethereum and dispatches the
* 'ethereum#initialized' event on window.
*
* @param providerInstance - The provider instance.
*/
export function setGlobalProvider(providerInstance) {
window.ethereum = providerInstance;
window.dispatchEvent(new Event('ethereum#initialized'));
}
/**
* Announces [CAIP-294](https://github.com/ChainAgnostic/CAIPs/blob/bc4942857a8e04593ed92f7dc66653577a1c4435/CAIPs/caip-294.md) wallet data according to build type and browser.
* Until released to stable, `extensionId` is only set in the `metamask_getProviderState` result if the build type is `flask`.
* `extensionId` is included if browser is chromium based because it is only useable by browsers that support [externally_connectable](https://developer.chrome.com/docs/extensions/reference/manifest/externally-connectable).
*
* @param provider - The provider {@link MetaMaskInpageProvider} used for retrieving `extensionId`.
* @param providerInfo - The provider info {@link BaseProviderInfo} that should be announced if set.
*/
export async function announceCaip294WalletData(provider, providerInfo) {
const buildType = getBuildType(providerInfo.rdns);
if (buildType !== 'flask') {
return;
}
const providerState = await provider.request({
method: 'metamask_getProviderState',
});
const extensionId = providerState?.extensionId;
const walletData = {
...providerInfo,
extensionId,
};
announceWallet(walletData);
}
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