1 files changed, 46 insertions, 0 deletions

diff --git a/editors/code/src/installation/fetch_latest_artifact_release_info.ts b/editors/code/src/installation/fetch_latest_artifact_release_info.ts
new file mode 100644
index 000000000..29ee029a7
--- /dev/null
+++ b/editors/code/src/installation/fetch_latest_artifact_release_info.ts
@@ -0,0 +1,46 @@
+import fetch from "node-fetch";
+import { GithubRepo, ArtifactReleaseInfo } from "./interfaces";
+
+const GITHUB_API_ENDPOINT_URL = "https://api.github.com";
+
+/**
+ * Fetches the latest release from GitHub `repo` and returns metadata about
+ * `artifactFileName` shipped with this release or `null` if no such artifact was published.
+ */
+export async function fetchLatestArtifactReleaseInfo(
+    repo: GithubRepo, artifactFileName: string
+): Promise<null | ArtifactReleaseInfo> {
+
+    const repoOwner = encodeURIComponent(repo.owner);
+    const repoName  = encodeURIComponent(repo.name);
+
+    const apiEndpointPath = `/repos/${repoOwner}/${repoName}/releases/latest`;
+    const requestUrl = GITHUB_API_ENDPOINT_URL + apiEndpointPath;
+
+    // We skip runtime type checks for simplicity (here we cast from `any` to `GithubRelease`)
+
+    console.log("Issuing request for released artifacts metadata to", requestUrl);
+
+    const response: GithubRelease = await fetch(requestUrl, {
+            headers: { Accept: "application/vnd.github.v3+json" }
+        })
+        .then(res => res.json());
+
+    const artifact = response.assets.find(artifact => artifact.name === artifactFileName);
+
+    if (!artifact) return null;
+
+    return {
+        releaseName: response.name,
+        downloadUrl: artifact.browser_download_url
+    };
+
+    // We omit declaration of tremendous amount of fields that we are not using here
+    interface GithubRelease {
+        name: string;
+        assets: Array<{
+            name: string;
+            browser_download_url: string;
+        }>;
+    }
+}