Add more prepublish checks

1 files changed, 28 insertions, 0 deletions

diff --git a/packages/monorepo-scripts/src/utils/npm_utils.ts b/packages/monorepo-scripts/src/utils/npm_utils.ts
new file mode 100644
index 000000000..cc1e046e7
--- /dev/null
+++ b/packages/monorepo-scripts/src/utils/npm_utils.ts
@@ -0,0 +1,28 @@
+import 'isomorphic-fetch';
+import * as _ from 'lodash';
+
+import { PackageRegistryJson } from '../types';
+
+const NPM_REGISTRY_BASE_URL = 'https://registry.npmjs.org';
+const SUCCESS_STATUS = 200;
+const NOT_FOUND_STATUS = 404;
+
+export const npmUtils = {
+    async getPackageRegistryJsonIfExistsAsync(packageName: string): Promise<PackageRegistryJson | undefined> {
+        const url = `${NPM_REGISTRY_BASE_URL}/${packageName}`;
+        const response = await fetch(url);
+
+        if (response.status === NOT_FOUND_STATUS) {
+            return undefined;
+        } else if (response.status !== SUCCESS_STATUS) {
+            throw new Error(`Request to ${url} failed. Check your internet connection and that npmjs.org is up.`);
+        }
+        const packageRegistryJson = await response.json();
+        return packageRegistryJson;
+    },
+    getPreviouslyPublishedVersions(packageRegistryJson: PackageRegistryJson): string[] {
+        const timeWithOnlyVersions = _.omit(packageRegistryJson.time, ['modified', 'created']);
+        const versions = _.keys(timeWithOnlyVersions);
+        return versions;
+    },
+};