First-time contributor github action (#16762)

* First draft of first-time contributor action

* Try using the github search api

* Minor tweaks

.github/actions/first-time-contributor/Dockerfile

@@ -0,0 +1,18 @@
+FROM debian:stable-slim
+
+LABEL "name"="First Time Contributor"
+LABEL "maintainer"="The WordPress Contributors"
+LABEL "version"="1.0.0"
+
+LABEL "com.github.actions.name"="First Time Contributor"
+LABEL "com.github.actions.description"="Assigns the first time contributor label to pull requests"
+LABEL "com.github.actions.icon"="award"
+LABEL "com.github.actions.color"="green"
+
+RUN apt-get update && \
+	apt-get install --no-install-recommends -y jq curl ca-certificates && \
+	apt-get clean -y
+
+COPY entrypoint.sh /entrypoint.sh
+
+ENTRYPOINT [ "/entrypoint.sh" ]

.github/actions/first-time-contributor/entrypoint.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+set -e
+
+# 1. Get the author and pr number for the pull request.
+author=$(jq -r '.pull_request.user.login' $GITHUB_EVENT_PATH)
+pr_number=$(jq -r '.number' $GITHUB_EVENT_PATH)
+
+if [ "$pr_number" = "null" ] || [ "$author" = "null" ]; then
+	echo "Could not find PR number or author. $pr_number / $author"
+	exit 78
+fi
+
+# 2. Fetch the author's commit count for the repo to determine if they're a first-time contributor.
+commit_count=$(
+	curl \
+		--silent \
+		-H "Accept: application/vnd.github.cloak-preview" \
+		"https://github.com/gitapi/search/commits?q=repo:$GITHUB_REPOSITORY+author:$author" \
+		| jq -r '.total_count'
+)
+
+# 3. If the response has a commit count of zero, exit early, the author is not a first time contributor.
+if [ "$commit_count" != "0" ]; then
+	echo "Pull request #$pr_number was not created by a first-time contributor ($author)."
+	exit 78
+fi
+
+# 4. Assign the 'First Time Contributor' label.
+curl \
+	--silent \
+	-X POST \
+	-H "Authorization: token $GITHUB_TOKEN" \
+	-H "Content-Type: application/json" \
+	-d '{"labels":["First-time Contributor"]}' \
+	"https://github.com/gitapi/repos/$GITHUB_REPOSITORY/issues/$pr_number/labels" > /dev/null

.github/main.workflow

@@ -23,3 +23,14 @@ action "Assign Fixed Issues" {
   needs = ["Filter opened"]
   secrets = ["GITHUB_TOKEN"]
 }
+
+workflow "Add the First-time Contributor label to PRs opened by first-time contributors" {
+  on = "pull_request"
+  resolves = ["First Time Contributor"]
+}
+
+action "First Time Contributor" {
+  uses = "./.github/actions/first-time-contributor"
+  needs = ["Filter opened"]
+  secrets = ["GITHUB_TOKEN"]
+}