feat(cfn): use exponential backoff with jitter for cfn api calls

CHANGELOG.md

@@ -1,5 +1,11 @@
 # cfn-changeset-viewer
 
+## 0.0.5
+
+### Patch Changes
+
+- add exponential backoff to cfn api call
+
 ## 0.0.4
 
 ### Patch Changes

flake.nix

@@ -0,0 +1,28 @@
+{
+  description = "cfn-changeset-viewer";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/release-23.11";
+  };
+  outputs = { nixpkgs, ... }:
+    let
+      shell = { system }:
+        let
+          pkgs = import nixpkgs {
+            system = system;
+          };
+        in
+        pkgs.mkShell {
+          buildInputs = [
+            pkgs.awscli2
+            pkgs.nodejs_20
+          ];
+        };
+    in
+    {
+      devShells.aarch64-darwin.default = shell { system = "aarch64-darwin"; };
+      devShells.x86_64-darwin.default = shell { system = "x86_64-darwin"; };
+      devShells.aarch64-linux.default = shell { system = "aarch64-linux"; };
+      devShells.x86_64-linux.default = shell { system = "x86_64-linux"; };
+    };
+}

index.mjs

@@ -41,13 +41,26 @@ async function printChangeSet(changeSetId, stackName, path, showUnchangedPropert
     Dynamic: 0,
   };
   if (!path) path = "";
-  const response = await cfn.send(
-    new DescribeChangeSetCommand({
-      ChangeSetName: changeSetId,
-      StackName: stackName,
-      IncludePropertyValues: true,
-    }),
-  );
+  let response;
+  let attempts = 0;
+
+  while (!response) {
+    try {
+      response = await cfn.send(
+        new DescribeChangeSetCommand({
+          ChangeSetName: changeSetId,
+          StackName: stackName,
+          IncludePropertyValues: true,
+        }),
+      );
+    } catch (err) {
+      if (!(err instanceof Error)) throw err;
+      if (err.name !== "Throttling") throw err;
+      if (attempts++ > 5) throw err;
+      // exponential backoff sleep with jitter
+      await new Promise((resolve) => setTimeout(resolve, 2 ** attempts * 1000 + Math.random() * 1000));
+    }
+  }
 
   for (let change of response.Changes ?? []) {
     const resourceChange = change.ResourceChange;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "cfn-changeset-viewer",
-  "version": "0.0.4",
+  "version": "0.0.5",
   "description": "View the details of a CloudFormation ChangeSet (including nested ones!) in a human-friendly way",
   "main": "index.mjs",
   "type": "module",