feat(reviewersInTeams): using teams to add reviews

* Using GitHub teams you can specify reviewers to be added to Pull
Request
* GitHub team's slug name is used under the label reviewersInTeams to
extract the members in the team

Fixes kentaro-m#123

Author: Thomas Truong

README.md

@@ -142,6 +142,40 @@ useAssigneeGroups: false
 #   - wip
 ```
 
+#### Add Members in Github Team(s) to Reviewers List
+
+Randomly add members in Github team(s) to the pull request based on number of reviewers listed using the `org/team_slug` syntax.
+
+```yaml
+# Set to true to add reviewers to pull requests
+addReviewers: true
+
+# Set to true to add assignees to pull requests
+addAssignees: false
+
+# A list of team reviewers to be added to pull requests (GitHub team slug)
+reviewersInTeams:
+  - org/teamReviewerA
+  - org/teamReviewerB
+
+# Number of reviewers has no impact on Github teams
+# Set 0 to add all the reviewers (default: 0)
+numberOfReviewers: 2
+
+# A list of assignees, overrides reviewers if set
+# assignees:
+#   - assigneeA
+
+# A number of assignees to add to the pull request
+# Set to 0 to add all of the assignees.
+# Uses numberOfReviewers if unset.
+# numberOfAssignees: 2
+
+# A list of keywords to be skipped the process that add reviewers if pull requests include it
+# skipKeywords:
+#   - wip
+```
+
 ### Assign Author as Assignee
 Add the PR creator as assignee to the pull request.
 

src/handler.ts

@@ -13,6 +13,61 @@ export interface Config {
   useAssigneeGroups: boolean
   reviewGroups: { [key: string]: string[] }
   assigneeGroups: { [key: string]: string[] }
+  reviewersInTeams: string[]
+}
+
+export async function getTeamMembers(
+  context: Context,
+  { org, teamSlug }: { org: string; teamSlug: string }
+): Promise<string[]> {
+  let members: { login: string }[] = []
+
+  try {
+    members = (
+      await context.github.teams.listMembersInOrg({
+        org,
+        // eslint-disable-next-line @typescript-eslint/camelcase
+        team_slug: teamSlug
+      })
+    ).data
+  } catch (error) {
+    context.log(error)
+  }
+
+  if (members.length === 0) {
+    let team
+
+    try {
+      team = (
+        await context.github.teams.getByName({
+          org,
+          // eslint-disable-next-line @typescript-eslint/camelcase
+          team_slug: teamSlug
+        })
+      ).data
+    } catch (error) {
+      context.log(error)
+      throw new Error(
+        `Cannot fetch team id for team ${teamSlug} under organisation ${org}.`
+      )
+    }
+
+    try {
+      members = (
+        await context.github.teams.listMembersLegacy({
+          // eslint-disable-next-line @typescript-eslint/camelcase
+          team_id: team.id
+        })
+      ).data
+    } catch (error) {
+      context.log(error)
+      throw new Error(
+        `Cannot fetch list of members in team ${teamSlug} under organisation ${org}.`
+      )
+    }
+  }
+
+  return members.map((member): string => member.login)
 }
 
 export async function handlePullRequest(context: Context): Promise<void> {
@@ -30,7 +85,8 @@ export async function handlePullRequest(context: Context): Promise<void> {
     useAssigneeGroups,
     assigneeGroups,
     addReviewers,
-    addAssignees
+    addAssignees,
+    reviewersInTeams
   } = config
 
   if (skipKeywords && includesSkipKeywords(title, skipKeywords)) {
@@ -54,6 +110,24 @@ export async function handlePullRequest(context: Context): Promise<void> {
     )
   }
 
+  if (reviewersInTeams && reviewersInTeams.length > 0) {
+    for (const team of reviewersInTeams) {
+      const result = /^([\w\-]+)\/([\w\-]+)$/.exec(team)
+      if (result === null) {
+        throw new Error(
+          'Error in configuration file to expand a team reviewersInTeams must be a list of org/team_slug.'
+        )
+      }
+      const reviewers = await getTeamMembers(context, {
+        org: result[1],
+        teamSlug: result[2]
+      })
+      config.reviewers = Array.from(
+        new Set((config.reviewers || []).concat(reviewers))
+      )
+    }
+  }
+
   const owner = context.payload.pull_request.user.login
 
   if (addReviewers) {