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FOR-581
One very useful thing about the fact that `describe` can contain arbitrary code is that it's very easy to programmatically generate test cases:

```
for numImages in [1, 2, 10]
  for truncatedText in [true, false]
    it "body with #{numImages} images and #{if truncatedText then "truncated" else "untruncated"} text", ->
      ...
```

With that change, you should be able to just put the body of checkPostWithImages in there instead of making it a separate function.