[STRATCONN-3623] - Adds github actions workflow to label PRs (#1905)

* Adds PR labeler workflow

* rename token

* update secret name

* fix script path

* change path

* Delete scripts folder

* dummy commit

* update registration regex

* Add comments on checks

.github/workflows/label-prs.yml

@@ -0,0 +1,55 @@
+# This workflow labels PRs based on the files that were changed. It uses a custom script to this
+# instead of actions/labeler as few of the tags are more than just file changes.
+
+name: Label PRs
+on:
+  pull_request:
+
+jobs:
+  pr-labeler:
+    runs-on: ubuntu-20.04
+    permissions:
+      contents: read
+      pull-requests: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Compute Labels
+        id: compute-labels
+        uses: actions/github-script@v7
+        with:
+          # Required for the script to access team membership information.
+          # Scope: members:read and contentes:read permission on the organization.
+          github-token: ${{ secrets.GH_PAT_MEMBER_AND_PULL_REQUEST_READONLY }}
+          script: |
+            const script = require('./scripts/compute-labels.js')
+            await script({github, context, core})
+      - name: Apply Labels
+        uses: actions/github-script@v7
+        env:
+          labelsToAdd: '${{ steps.compute-labels.outputs.add }}'
+          labelsToRemove: '${{ steps.compute-labels.outputs.remove }}'
+        with:
+          script: |
+            const { labelsToAdd, labelsToRemove } = process.env
+            if(labelsToAdd.length > 0) {
+              await github.rest.issues.addLabels({
+                issue_number: context.payload.pull_request.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                labels: labelsToAdd.split(',')
+              });
+            }
+            if(labelsToRemove.length > 0) {
+              const requests = labelsToRemove.split(',').map(label => {
+                return github.rest.issues.removeLabel({
+                  issue_number: context.payload.pull_request.number,
+                  name: label,
+                  owner: context.repo.owner,
+                  repo: context.repo.repo
+                });
+              });
+              await Promise.all(requests);
+            }

scripts/compute-labels.js

@@ -0,0 +1,146 @@
+// This is a github action script and can be run only from github actions. It is not possible to run this script locally.
+module.exports = async ({ github, context, core }) => {
+  const authorLabels = await computeAuthorLabels(github, context, core)
+  const { add, remove } = await computeFileBasedLabels(github, context, core)
+  core.setOutput('add', [...authorLabels, ...add].join(','))
+  core.setOutput('remove', remove.join(','))
+  return
+}
+
+async function computeAuthorLabels(github, context, core) {
+  const teamSlugs = ['build-experience-team', 'libraries-web-team', 'strategic-connections-team']
+  const username = context.payload.sender.login
+  const organization = context.repo.owner
+  const SEGMENT_CORE_LABEL = 'team:segment-core'
+  const EXTERNAL_LABEL = 'team:external'
+  const SEGMENT_LABEL = 'team:segment'
+
+  // If team member label already exists, then no need to add any labels
+  const existingLabels = context.payload.pull_request.labels.map((label) => label.name)
+  if (existingLabels.some((label) => [SEGMENT_CORE_LABEL, EXTERNAL_LABEL, SEGMENT_LABEL].includes(label))) {
+    return []
+  }
+
+  // check against all internal teams
+  const teamMembers = await Promise.all(
+    teamSlugs.map(async (teamSlug) => {
+      const team = await github.rest.teams.listMembersInOrg({
+        team_slug: teamSlug,
+        org: organization
+      })
+      return team.data.some((member) => member.login === username)
+    })
+  )
+
+  // Add labels based on the team membership
+  const labels = []
+  if (teamMembers.some((member) => member === true)) {
+    labels.push(SEGMENT_CORE_LABEL)
+  } else {
+    // check if the user is a member of the organization - eg; Engage and other internal integration devs
+    await github.rest.orgs
+      .checkMembershipForUser({
+        org: organization,
+        username: username
+      })
+      // if the user is not a member of the organization, then add the external label
+      .catch((e) => {
+        if (e.status === 404) {
+          labels.push(EXTERNAL_LABEL)
+        }
+      })
+      // if the user is a member of the organization, then add the segment label
+      .then((data) => {
+        if (data && data.status === 204) {
+          labels.push(SEGMENT_LABEL)
+        }
+      })
+  }
+  core.debug(`Added ${labels.join(',')} labels to PR based on the author's team membership.`)
+  return labels
+}
+
+async function computeFileBasedLabels(github, context, core) {
+  const org = context.repo.owner
+  const repo = context.repo.repo
+  const pull_number = context.payload.pull_request.number
+  const labels = context.payload.pull_request.labels.map((label) => label.name)
+  const DEPLOY_REGISTRATION_LABEL = 'deploy:registration'
+  const DEPLOY_PUSH_LABEL = 'deploy:push'
+  const MODE_CLOUD_LABEL = 'mode:cloud'
+  const MODE_DEVICE_LABEL = 'mode:device'
+  const ACTIONS_CORE_LABEL = 'actions:core'
+
+  const allLabels = [
+    DEPLOY_REGISTRATION_LABEL,
+    DEPLOY_PUSH_LABEL,
+    MODE_CLOUD_LABEL,
+    MODE_DEVICE_LABEL,
+    ACTIONS_CORE_LABEL
+  ]
+
+  const newLabels = []
+
+  // Get the list of files in the PR
+  const opts = github.rest.pulls.listFiles.endpoint.merge({
+    owner: org,
+    repo: repo,
+    pull_number: pull_number
+  })
+
+  // Paginate the list of files in the PR
+  const files = await github.paginate(opts)
+
+  // The following regexes are used to match the new destinations
+  const newCloudDestinationRegex = /packages\/destination\-actions\/src\/destinations\/[^\/]+\/index\.ts/i
+  const newBrowserDestinationRegex = /packages\/browser\-destinations\/destinations\/[^\/]+\/src\/index\.ts/i
+  const isNew = (filename) => newCloudDestinationRegex.test(filename) || newBrowserDestinationRegex.test(filename)
+
+  // Check if the PR contains new destinations
+  const isNewDestination = files.some((file) => isNew(file.filename) && file.status === 'added')
+  if (isNewDestination) {
+    newLabels.push(DEPLOY_REGISTRATION_LABEL)
+  }
+
+  // The following regexes are used to match the updated destinations
+  const updatedCloudDestinationRegex = /packages\/destination\-actions\/src\/destinations\/.*/i
+  const updatedBrowserDestinationRegex = /packages\/browser\-destinations\/destinations\/.*/i
+  const updateCorePackageRegex = /packages\/core\/.*/i
+  const updatedDestinationSubscription = /packages\/destination\-subscriptions\/.*/i
+
+  // Check if the PR contains updates to browser destinations
+  if (files.some((file) => updatedBrowserDestinationRegex.test(file.filename))) {
+    newLabels.push(MODE_DEVICE_LABEL)
+  }
+
+  // Check if the PR contains updates to cloud destinations
+  if (files.some((file) => updatedCloudDestinationRegex.test(file.filename))) {
+    newLabels.push(MODE_CLOUD_LABEL)
+  }
+
+  // Check if the PR contains updates to core packages
+  if (
+    files.some(
+      (file) => updateCorePackageRegex.test(file.filename) || updatedDestinationSubscription.test(file.filename)
+    )
+  ) {
+    newLabels.push(ACTIONS_CORE_LABEL)
+  }
+
+  // Check if the PR contains changes that requires a push.
+  const generatedTypesRegex = /packages\/.*\/generated\-types.ts/i
+  if (files.some((file) => generatedTypesRegex.test(file.filename))) {
+    newLabels.push(DEPLOY_PUSH_LABEL)
+  }
+
+  // Remove the existing custom labels if they are not required anymore
+  const labelsToRemove = labels.filter((label) => allLabels.includes(label) && !newLabels.includes(label))
+
+  core.debug(`Labels to remove: ${labelsToRemove.join(',')}`)
+  core.debug(`Labels to add: ${newLabels.join(',')}`)
+
+  return {
+    add: newLabels,
+    remove: labelsToRemove
+  }
+}