Serverless Stack

I've been trying to capture the output of `sst diff` into a variable within bash, but it appears the actual CDK diff is output via an inner child process or something. I end up getting something like this:

```❯ body=$(./node_modules/.bin/sst diff --stage dev)
Stack dev-foo
IAM Statement Changes
... actual CDK DIFF```
And outputting body variable:
```❯ echo "$body"
Using stage: dev
Preparing your SST app
Building function src/foo/bar.handler
...```
Anyone tried anything similar? I almost have a GitHub action working here. Just need to be able to nab the correct output. :smile:

Granted all this would be far easier to go via SEED, unfortunately the client is all bought into GitHub workflow already.

you might be better off trying this in node instead of Bash

I have a very similar GitHub action, that runs Jest and outputs the coverage into a PR comment. The linked line is where I run the command and grab the output: <https://github.com/dkershner6/jest-coverage-commenter-action/blob/58ed25dae88c7231f0d29779a58d976acbf02941/src/tasks/runJest.ts#L21>