chore(CI): Check PR body and title. (ChainSafe#1786)

* chore(CI): Check PR body and title.

* Trigger CI

* Fix regex.

.github/PULL_REQUEST/pull_request.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"os"
+
+	"github.com/ChainSafe/gossamer/lib/utils"
+)
+
+func main() {
+	title := os.Getenv("RAW_TITLE")
+	body := os.Getenv("RAW_BODY")
+	err := utils.CheckPRDescription(title, body)
+	if err != nil {
+		os.Exit(1)
+	}
+}

.github/workflows/checks.yml

@@ -27,4 +27,17 @@ jobs:
       - uses: actions/checkout@v2
 
       - name: Run go vet
-        run: go vet ./...
+        run: go vet ./...
+
+  check-description:
+    name: Checks PR has title and body description
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Checks PR has title and body description
+        run: |
+          go run .github/PULL_REQUEST/pull_request.go
+
+        env:
+          RAW_TITLE: ${{ github.event.pull_request.title }}
+          RAW_BODY: ${{ github.event.pull_request.body }}

lib/utils/pull_request.go

@@ -0,0 +1,44 @@
+package utils
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+const (
+	titleRegex = `[A-Za-z]+\([A-Za-z/]+\):.+[A-Za-z]+`
+	bodyRegex  = `## Changes.*- .*[A-Za-z0-9].*## Tests.*[A-Za-z].*## Issues.*- .*[A-Za-z0-9].*## Primary Reviewer.*- @.+[A-Za-z0-9].*`
+)
+
+// CheckPRDescription matches the PR title and body according to the PR template.
+func CheckPRDescription(title, body string) error {
+	match, err := regexp.MatchString(titleRegex, title)
+	if err != nil || !match {
+		return fmt.Errorf("title pattern is not valid: %w match %t", err, match)
+	}
+
+	var bodyData string
+	// Remove comment from PR body.
+	for {
+		start := strings.Index(body, "<!--")
+		end := strings.Index(body, "-->")
+		if start < 0 || end < 0 {
+			break
+		}
+
+		bodyData = bodyData + body[:start]
+		body = body[end+4:]
+	}
+	bodyData = bodyData + body
+
+	lineSplit := strings.Split(bodyData, "\n")
+	joinedLine := strings.Join(lineSplit, "")
+
+	// Regex for body data
+	match, err = regexp.MatchString(bodyRegex, joinedLine)
+	if err != nil || !match {
+		return fmt.Errorf("body pattern is not valid: %w match %t", err, match)
+	}
+	return nil
+}

lib/utils/pull_request_test.go

@@ -0,0 +1,55 @@
+package utils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_PR_Checks(t *testing.T) {
+	tests := []struct {
+		title string
+		body  string
+		valid bool
+	}{
+		{
+			title: "",
+			body:  "",
+			valid: false,
+		},
+		{
+			title: "abc(abc): abc",
+			body:  "",
+			valid: false,
+		},
+		{
+			title: `feat(dot/rpc): implement chain_subscribeAllHeads RPC`,
+			body:  `## Changes\n\n<!--\nPlease provide a brief but specific list of changes made, describe the changes\nin functionality rather than the changes in code.\n-->\n\n- changes for demo :123\n\n## Tests\n\n<!--\nDetails on how to run tests relevant to the changes within this pull request.\n-->\n\n- tests for demo:123{}\n\n## Issues\n\n<!--\nPlease link any issues that this pull request is related to and use the GitHub\nsupported format for automatically closing issues (ie, closes #123, fixes #123)\n-->\n\n- issues for demo:43434\n\n## Primary Reviewer\n\n<!--\nPlease indicate one of the code owners that are required to review prior to merging changes (e.g. @noot)\n-->\n\n- @noot for demo:12`,
+			valid: true,
+		},
+		{
+			title: "abc(): abc",
+			body:  "",
+			valid: false,
+		},
+		{
+			title: "(abc): abc",
+			body:  "",
+			valid: false,
+		},
+		{
+			title: "abc(abc):",
+			body:  "",
+			valid: false,
+		},
+	}
+
+	for _, test := range tests {
+		err := CheckPRDescription(test.title, test.body)
+		if test.valid {
+			require.NoError(t, err, "title", test.title, "body", test.body)
+		} else {
+			require.Error(t, err, "title", test.title, "body", test.body)
+		}
+	}
+}