Add #handbook label to handbook only PRs (#6967)

* add #handbook label to handbook PRs

* Update get-is-pr-only-handbook-changes.js

* remove while loop from _.all()

* revert changes to github token name

* Simplifications

Co-authored-by: Mike McNeil <mikermcneil@users.noreply.github.com>

website/api/controllers/webhooks/receive-from-github.js

@@ -238,6 +238,8 @@ module.exports = {
           isGithubUserMaintainerOrDoesntMatter: GITHUB_USERNAMES_OF_BOTS_AND_MAINTAINERS.includes(sender.login.toLowerCase())
         });
 
+        let isHandbookPR = await sails.helpers.githubAutomations.getIsPrOnlyHandbookChanges.with({prNumber: prNumber});
+
         // Check whether the "main" branch is currently frozen (i.e. a feature freeze)
         // [?] https://docs.mergefreeze.com/web-api#get-freeze-status
         let mergeFreezeMainBranchStatusReport = await sails.helpers.http.get('https://www.mergefreeze.com/api/branches/fleetdm/fleet/main', { access_token: sails.config.custom.mergeFreezeAccessToken }); //eslint-disable-line camelcase
@@ -249,6 +251,14 @@ module.exports = {
           Date.now() < (new Date('Jul 28, 2022 14:00 UTC')).getTime()
         );
 
+        // Add the #handbook label to PRs that only make changes to the handbook.
+        if(isHandbookPR) {
+          // [?] https://docs.github.com/en/rest/issues/labels#add-labels-to-an-issue
+          await sails.helpers.http.post(`https://api.github.com/repos/${owner}/${repo}/issue/${prNumber}/labels`, {
+            labels: '#handbook'
+          }, baseHeaders);
+        }
+
         // Now, if appropriate, auto-approve the change.
         if (isAutoApproved) {
           // [?] https://docs.github.com/en/rest/reference/pulls#create-a-review-for-a-pull-request

website/api/helpers/github-automations/get-is-pr-only-handbook-changes.js

@@ -0,0 +1,52 @@
+module.exports = {
+
+
+  friendlyName: 'Get "Is PR only handbook changes"',
+
+
+  description: 'Checks each file in a GitHub pull request, and returns true if the PR only changes files in the handbook folder',
+
+
+  inputs: {
+    prNumber: { type: 'number', example: 382, required: true },
+  },
+
+  exits: {
+
+    success: {
+      outputFriendlyName: 'Is PR only handbook changes',
+      outputDescription: 'Whether the provided pull request only makes changes to the handbook',
+      outputType: 'boolean',
+    },
+
+  },
+
+
+  fn: async function ({prNumber}) {
+
+    require('assert')(sails.config.custom.githubAccessToken);
+
+    let owner = 'fleetdm';
+    let repo = 'fleet';
+    let baseHeaders = {
+      'User-Agent': 'Fleet labels',
+      'Authorization': `token ${sails.config.custom.githubAccessToken}`
+    };
+
+    // [?] https://docs.github.com/en/rest/reference/pulls#list-pull-requests-files
+    let changedPaths = _.pluck(await sails.helpers.http.get(`https://api.github.com/repos/${owner}/${repo}/pulls/${prNumber}/files`, {
+      per_page: 100,//eslint-disable-line camelcase
+    }, baseHeaders).retry(), 'filename');// (don't worry, it's the whole path, not the filename)
+
+    // Check the path of each file that this PR makes changes to.
+    let isHandbookOnlyPR = _.all(changedPaths, (changedPath)=>{
+      return changedPath.match(/^handbook\//);
+    });//∞
+
+    return isHandbookOnlyPR;
+
+  }
+
+
+};
+