add memoization to getPullRequestComments

Author: kfbustam

source/platforms/github/GitHubAPI.ts

@@ -10,6 +10,7 @@ import { dangerIDToString } from "../../runner/templates/githubIssueTemplate"
 import { api as fetch } from "../../api/fetch"
 import { RepoMetaData } from "../../dsl/RepoMetaData"
 import { CheckOptions } from "./comms/checks/resultsToCheck"
+import memoize from "lodash.memoize"
 
 // The Handle the API specific parts of the github
 
@@ -325,13 +326,13 @@ export class GitHubAPI {
    * @returns {Promise<GitHubIssueComment[]>} A promise that resolves to an array of GitHub issue comments.
    *
    */
-  getPullRequestComments = async (): Promise<GitHubIssueComment[]> => {
+  getPullRequestComments = memoize(async (): Promise<GitHubIssueComment[]> => {
     const pr = await this.getPullRequestInfo()
     const prNumber = pr.number
     const repo = this.repoMetadata.repoSlug
     const owner = pr.base.repo.owner.login
     return await this.getAllOfResource(`repos/${owner}/${repo}/issues/${prNumber}/comments`)
-  }
+  })
 
   getPullRequestInlineComments = async (
     dangerID: string