pr_validator.yml

# Original idea by SByteDev
# https://github.com/SByteDev

name: 🔍 PR Validator

on:
   pull_request:
     types:
      - opened
      - edited
      - reopened
      - synchronize

   workflow_dispatch:

jobs:
  Validate:
    runs-on: ubuntu-latest

    steps:
      - name: Echo Credits
        run: echo Credits to SByteDev''s branch validator. See https://github.com/SByteDev/BranchNameGenerator
      - name: Validate
        uses: actions/github-script@v5.0.0
        with:
          script: |
            // See https://github.com/SByteDev/BranchNameGenerator
            function generateBranchName(task, prefix, divider, version) {
               if (task === undefined || task === "") {
                  return "";
               }
               // Replace non-word characters with divider.
               var branch = task.replace(/([\W])/g, divider);
                 // Remove duplicated dividers.
               if (divider == "-") {
                  branch = branch.replace(/-+/g, divider);
               } else {
                  branch = branch.replace(/_+/g, divider);
               }
                 // Replace uppercase characters with lovercase characters.
               branch = branch.toLowerCase();
                 // Remove first divider.
               if (branch[0] === divider) {
                  branch = branch.substring(1, branch.length);
               }
               // Remove last divider.
               if (branch[branch.length - 1] === divider) {
                  branch = branch.substring(0, branch.length - 1);
               }
               if (prefix !== undefined && prefix !== "") {
                  // Add tack type folder.
                  branch = prefix + "/" + branch;
               }
               if (version !== undefined && version !== "") {
                  // Add version folder.
                  branch = version + "/" + branch;
               }
               return branch;
            };

            const prTitle = context.payload.pull_request.title;
            const prDescription = context.payload.pull_request.body;
            const prBranch = context.payload.pull_request.head.ref

            const prDescriptionToLower = prDescription.toLowerCase();

            var isIssueFound = false;

            const regex = /(resolves) #(\d+)/g;
            const matches = prDescriptionToLower.match(regex);

            if (!matches) {
               core.setFailed("The PR description must start with \"Resolves #{issue_number}\", where {issue_number} — is the number of the main linked issue.");
               return;
            }

            console.log("Found a linked issue!");

            var firstMatch = matches[0];

            if (!prDescriptionToLower.startsWith(firstMatch)) {
              core.setFailed("The PR description must start with \"Resolves #{issue_number}\", where {issue_number} — is the number of the main linked issue.");
              return;
            }

            const issueId = firstMatch.replace('resolves #','').trim();

            console.log("Getting data of \#" + issueId + " ...");

            const issue = await github.rest.issues.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: issueId,
            });

            if (!issue) {
              core.setFailed("Issue with such a number was not found.");
              return;
            }

            console.log("Checking if \#" + issueId + " is not a PR ...");

            if (issue.data.pull_request) {
              core.setFailed("\#" + issueId + " is a PR, but must be an issue.");
              return;
            }

            console.log("Comparing titles ...");

            if (issue.data.title != prTitle) {
              core.setFailed("The title of the PR must be equal with the linked issue title.");
              return;
            }

            console.log("Looking for branch prefix depending on issue's labels ...");

            var branchPrefix;

            const labels = issue.data.labels

            if (!labels) {
              branchPrefix = ""
            } else {
              for (index in labels) {
                const label = labels[index]

                if (label.name.includes("bug")) {
                  console.log("Found a bug label!");

                  if (branchPrefix == "feature") {
                    core.setFailed("The issue contains both bug and feature labels: that's not correct");
                  }

                  branchPrefix = "bug"
                }

                if (label.name.includes("feature")) {
                  console.log("Found a feature label!");

                  if (branchPrefix == "bug") {
                    core.setFailed("The issue contains both bug and feature labels: that's not correct");
                  }

                  branchPrefix = "feature"
                }
              }
            }

            console.log("Validating branch name ...");

            const expectedBranchName = generateBranchName(
              issue.data.title,
              branchPrefix,
              "-",
              ""
            );

            if (expectedBranchName != prBranch) {
              core.setFailed("The PR git branch doesn't follow the required rules.\nExpected: " + expectedBranchName + "\nActual: " + prBranch);
              return;
            }

            console.log("The PR is valid! 👍");