feat(web): add automatic actions for open pull requests

A new pr_open alert carries the head commit SHA of each open, non-draft, same-repository pull request. An action with auto enabled sends its webhook once for each pull request and head commit. An authors list limits which pull requests trigger it. The alert never changes repository health.

internal/config/config.go

@@ -45,6 +45,23 @@ type Action struct {
 	Webhook Webhook `yaml:"webhook"`
 	// Kinds limits the action to these alert kinds; empty means every kind.
 	Kinds []string `yaml:"kinds"`
+	// Authors limits auto firing to pull requests by these logins, case-insensitive; empty means anyone.
+	Authors []string `yaml:"authors"`
+	// Auto fires the webhook without a click, once per alert and head commit; it requires Kinds.
+	Auto bool `yaml:"auto"`
+}
+
+// AuthorAllowed reports whether auto firing accepts a pull request author.
+func (a Action) AuthorAllowed(author string) bool {
+	if len(a.Authors) == 0 {
+		return true
+	}
+	for _, x := range a.Authors {
+		if strings.EqualFold(x, author) {
+			return true
+		}
+	}
+	return false
 }
 
 type Webhook struct {
@@ -196,6 +213,9 @@ func finalizeActions(actions []Action, getenv func(string) string) error {
 		if a.StatusURL != "" && !isHTTPURL(a.StatusURL) {
 			return fmt.Errorf("actions[%s].status_url %q must be an http or https address", a.ID, a.StatusURL)
 		}
+		if a.Auto && len(a.Kinds) == 0 {
+			return fmt.Errorf("actions[%s].auto requires a non-empty kinds list", a.ID)
+		}
 		if a.Webhook.Timeout < 0 {
 			return fmt.Errorf("actions[%s].webhook.timeout must not be negative", a.ID)
 		}

internal/config/config_test.go

@@ -177,6 +177,8 @@ func TestActionsFinalize(t *testing.T) {
 		"status url ok":    {mutate: func(a *Action) { a.StatusURL = "http://status.example.test/s" }},
 		"negative timeout": {mutate: func(a *Action) { a.Webhook.Timeout = -time.Second }, wantErr: true},
 		"token env unset":  {mutate: func(a *Action) { a.Webhook.TokenEnv = "MISSING" }, wantErr: true},
+		"auto with kinds":  {mutate: func(a *Action) { a.Auto, a.Kinds = true, []string{"pr_open"} }},
+		"auto no kinds":    {mutate: func(a *Action) { a.Auto = true }, wantErr: true},
 	}
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
@@ -221,3 +223,24 @@ func TestActionAppliesTo(t *testing.T) {
 		}
 	}
 }
+
+func TestActionAuthorAllowed(t *testing.T) {
+	tests := map[string]struct {
+		author  string
+		authors []string
+		want    bool
+	}{
+		"no filter":        {"anyone", nil, true},
+		"listed":           {"alice", []string{"alice"}, true},
+		"case-insensitive": {"aLICE", []string{"Alice"}, true},
+		"unlisted":         {"bob", []string{"alice"}, false},
+		"empty author":     {"", []string{"alice"}, false},
+	}
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			if got := (Action{Authors: tc.authors}).AuthorAllowed(tc.author); got != tc.want {
+				t.Fatalf("AuthorAllowed(%q) = %v, want %v", tc.author, got, tc.want)
+			}
+		})
+	}
+}