* first action! (#1)

node_modules/package-json/index.js

@@ -0,0 +1,115 @@
+'use strict';
+const {URL} = require('url');
+const {Agent: HttpAgent} = require('http');
+const {Agent: HttpsAgent} = require('https');
+const got = require('got');
+const registryUrl = require('registry-url');
+const registryAuthToken = require('registry-auth-token');
+const semver = require('semver');
+
+// These agent options are chosen to match the npm client defaults and help with performance
+// See: `npm config get maxsockets` and #50
+const agentOptions = {
+	keepAlive: true,
+	maxSockets: 50
+};
+const httpAgent = new HttpAgent(agentOptions);
+const httpsAgent = new HttpsAgent(agentOptions);
+
+class PackageNotFoundError extends Error {
+	constructor(packageName) {
+		super(`Package \`${packageName}\` could not be found`);
+		this.name = 'PackageNotFoundError';
+	}
+}
+
+class VersionNotFoundError extends Error {
+	constructor(packageName, version) {
+		super(`Version \`${version}\` for package \`${packageName}\` could not be found`);
+		this.name = 'VersionNotFoundError';
+	}
+}
+
+const packageJson = async (packageName, options) => {
+	options = {
+		version: 'latest',
+		...options
+	};
+
+	const scope = packageName.split('/')[0];
+	const registryUrl_ = options.registryUrl || registryUrl(scope);
+	const packageUrl = new URL(encodeURIComponent(packageName).replace(/^%40/, '@'), registryUrl_);
+	const authInfo = registryAuthToken(registryUrl_.toString(), {recursive: true});
+
+	const headers = {
+		accept: 'application/vnd.npm.install-v1+json; q=1.0, application/json; q=0.8, */*'
+	};
+
+	if (options.fullMetadata) {
+		delete headers.accept;
+	}
+
+	if (authInfo) {
+		headers.authorization = `${authInfo.type} ${authInfo.token}`;
+	}
+
+	const gotOptions = {
+		json: true,
+		headers,
+		agent: {
+			http: httpAgent,
+			https: httpsAgent
+		}
+	};
+
+	if (options.agent) {
+		gotOptions.agent = options.agent;
+	}
+
+	let response;
+	try {
+		response = await got(packageUrl, gotOptions);
+	} catch (error) {
+		if (error.statusCode === 404) {
+			throw new PackageNotFoundError(packageName);
+		}
+
+		throw error;
+	}
+
+	let data = response.body;
+
+	if (options.allVersions) {
+		return data;
+	}
+
+	let {version} = options;
+	const versionError = new VersionNotFoundError(packageName, version);
+
+	if (data['dist-tags'][version]) {
+		data = data.versions[data['dist-tags'][version]];
+	} else if (version) {
+		if (!data.versions[version]) {
+			const versions = Object.keys(data.versions);
+			version = semver.maxSatisfying(versions, version);
+
+			if (!version) {
+				throw versionError;
+			}
+		}
+
+		data = data.versions[version];
+
+		if (!data) {
+			throw versionError;
+		}
+	}
+
+	return data;
+};
+
+module.exports = packageJson;
+// TODO: remove this in the next major version
+module.exports.default = packageJson;
+module.exports.PackageNotFoundError = PackageNotFoundError;
+module.exports.VersionNotFoundError = VersionNotFoundError;