IssueComment author field is null

You can test in the Explorer: https://developer.github.com/v4/explorer/ 

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      "body": "Thanks!! \r\nBy adding:\r\n ``` json\r\n \"compilerOptions\": {\r\n \"lib\": [\r\n \"esnext.asynciterable\"\r\n],\r\n. . .\r\n```\r\nto tsconfig.json file fixed the issue for good.",
      "bodyHTML": "<p>Thanks!!
\nBy adding:</p>\n<div class=\"highlight highlight-source-json\"><pre><span class=\"pl-s\"><span class=\"pl-pds\">\"</span>compilerOptions<span class=\"pl-pds\">\"</span></span>: {\n <span class=\"pl-s\"><span class=\"pl-pds\">\"</span>lib<span class=\"pl-pds\">\"</span></span>: [\n <span class=\"pl-s\"><span class=\"pl-pds\">\"</span>esnext.asynciterable<span class=\"pl-pds\">\"</span></span>\n],\n<span class=\"pl-ii\">.</span> <span class=\"pl-ii\">.</span> <span class=\"pl-ii\">.</span></pre></div>\n<p>to tsconfig.json file fixed the issue for good.</p>",
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The value of “author” is null.

See the IssueComment node: https://github.com/apollographql/graphql-subscriptions/issues/83#issuecomment-312469236

That’s correct. This is because ghost is the user that takes the place of people who delete their account:

Any time someone deletes their account, we change all the references to it to NULL and when NULL is found where a user should be, we display ghost rather than NULL.

I hope that helps!