Alerting: Refactor placeholder email detection into shared utility

- Extract duplicate placeholder email detection logic into reusable functions
- Add hasPlaceholderEmail() for single channel checks
- Add receiverHasPlaceholderEmail() for receiver list checks
- Centralize PLACEHOLDER_EMAILS constant in receiver-form.ts
- Update ChannelSubForm, TestContactPointModal, and actions to use utilities
- Reduces code duplication by 44 lines

public/app/features/alerting/unified/components/receivers/form/ChannelSubForm.tsx

@@ -16,6 +16,7 @@ import {
   GrafanaChannelValues,
   ReceiverFormValues,
 } from '../../../types/receiver-form';
+import { hasPlaceholderEmail } from '../../../utils/receiver-form';
 import { OnCallIntegrationType } from '../grafanaAppReceivers/onCall/useOnCallIntegration';
 
 import { ChannelOptions } from './ChannelOptions';
@@ -71,15 +72,8 @@ export function ChannelSubForm<R extends ChannelValues>({
   const isTestAvailable = onCallIntegrationType !== OnCallIntegrationType.NewIntegration;
 
   // Check if email integration has placeholder addresses
-  const emailAddresses = watch(`${settingsFieldPath}.addresses`);
-  const hasPlaceholderEmail = useMemo(() => {
-    if (selectedType !== 'email' || !emailAddresses) {
-      return false;
-    }
-    const placeholders = ['<example@email.com>', 'example@email.com'];
-    const addresses = typeof emailAddresses === 'string' ? [emailAddresses] : emailAddresses;
-    return addresses.some((addr: string) => placeholders.includes(addr?.trim()));
-  }, [selectedType, emailAddresses]);
+  const channelValues = getValues(channelFieldPath) as GrafanaChannelValues | undefined;
+  const isPlaceholderEmail = hasPlaceholderEmail(channelValues);
 
   useEffect(() => {
     register(`${channelFieldPath}.__id`);
@@ -242,14 +236,14 @@ export function ChannelSubForm<R extends ChannelValues>({
         <div className={styles.buttons}>
           {isTestable && onTest && isTestAvailable && (
             <Button
-              disabled={hasPlaceholderEmail}
+              disabled={isPlaceholderEmail}
               size="xs"
               variant="secondary"
               type="button"
               onClick={() => handleTest()}
               icon="message"
               tooltip={
-                hasPlaceholderEmail
+                isPlaceholderEmail
                   ? t(
                       'alerting.channel-sub-form.test-disabled-placeholder',
                       'Please configure a valid email address before testing'
@@ -283,7 +277,7 @@ export function ChannelSubForm<R extends ChannelValues>({
       </div>
       {notifier && (
         <div className={styles.innerContent}>
-          {hasPlaceholderEmail && (
+          {isPlaceholderEmail && (
             <Alert
               title={t(
                 'alerting.contact-points.email.placeholder-warning-title',

public/app/features/alerting/unified/components/receivers/form/TestContactPointModal.tsx

@@ -1,5 +1,5 @@
 import { css } from '@emotion/css';
-import { useMemo, useState } from 'react';
+import { useState } from 'react';
 import { FormProvider, useForm } from 'react-hook-form';
 
 import { GrafanaTheme2 } from '@grafana/data';
@@ -12,6 +12,7 @@ import { useTestIntegrationMutation } from '../../../api/receiversApi';
 import { GrafanaChannelValues } from '../../../types/receiver-form';
 import { defaultAnnotations } from '../../../utils/constants';
 import { stringifyErrorLike } from '../../../utils/misc';
+import { hasPlaceholderEmail } from '../../../utils/receiver-form';
 import AnnotationsStep from '../../rule-editor/AnnotationsStep';
 import LabelsField from '../../rule-editor/labels/LabelsField';
 
@@ -58,18 +59,7 @@ export const TestContactPointModal = ({
   const [testIntegration, { isLoading, error, isSuccess }] = useTestIntegrationMutation();
 
   // Check if email integration has placeholder addresses
-  const hasPlaceholderEmail = useMemo(() => {
-    if (!channelValues || channelValues.type !== 'email') {
-      return false;
-    }
-    const addresses = channelValues.settings?.addresses;
-    if (!addresses) {
-      return false;
-    }
-    const placeholders = ['<example@email.com>', 'example@email.com'];
-    const addressList = typeof addresses === 'string' ? [addresses] : addresses;
-    return addressList.some((addr: string) => placeholders.includes(addr?.trim()));
-  }, [channelValues]);
+  const isPlaceholderEmail = hasPlaceholderEmail(channelValues);
 
   const onSubmit = async (data: FormFields) => {
     let alert: TestReceiversAlert | undefined;
@@ -114,7 +104,7 @@ export const TestContactPointModal = ({
         />
       )}
 
-      {hasPlaceholderEmail && (
+      {isPlaceholderEmail && (
         <div className={styles.section}>
           <Alert
             title={t(
@@ -171,9 +161,9 @@ export const TestContactPointModal = ({
           <Modal.ButtonRow>
             <Button
               type="submit"
-              disabled={isLoading || hasPlaceholderEmail}
+              disabled={isLoading || isPlaceholderEmail}
               tooltip={
-                hasPlaceholderEmail
+                isPlaceholderEmail
                   ? t(
                       'alerting.test-contact-point-modal.test-disabled-placeholder',
                       'Please configure a valid email address before testing'

public/app/features/alerting/unified/state/actions.ts

@@ -30,6 +30,7 @@ import { FetchRulerRulesFilter, fetchRulerRules } from '../api/ruler';
 import { addDefaultsToAlertmanagerConfig } from '../utils/alertmanager';
 import { getAllRulesSourceNames } from '../utils/datasource';
 import { makeAMLink } from '../utils/misc';
+import { receiverHasPlaceholderEmail } from '../utils/receiver-form';
 import { withAppEvents, withSerializedError } from '../utils/redux';
 import { getAlertInfo } from '../utils/rules';
 import { safeParsePrometheusDuration } from '../utils/time';
@@ -272,27 +273,10 @@ interface TestReceiversOptions {
   alert?: TestReceiversAlert;
 }
 
-// Check if a receiver uses placeholder email addresses
-function hasPlaceholderEmail(receivers: Receiver[]): boolean {
-  const placeholderEmails = ['<example@email.com>', 'example@email.com'];
-  
-  return receivers.some((receiver) =>
-    receiver.grafana_managed_receiver_configs?.some((config) => {
-      if (config.type === 'email' && config.settings?.addresses) {
-        const addresses = config.settings.addresses;
-        // addresses can be a string or array
-        const addressList = typeof addresses === 'string' ? [addresses] : addresses;
-        return addressList.some((addr: string) => placeholderEmails.includes(addr.trim()));
-      }
-      return false;
-    })
-  );
-}
-
 export const testReceiversAction = createAsyncThunk(
   'unifiedalerting/testReceivers',
   async ({ alertManagerSourceName, receivers, alert }: TestReceiversOptions): Promise<void> => {
-    const usesPlaceholder = hasPlaceholderEmail(receivers);
+    const usesPlaceholder = receiverHasPlaceholderEmail(receivers);
     
     if (usesPlaceholder) {
       // Handle placeholder email case with custom warning message

public/app/features/alerting/unified/utils/receiver-form.ts

@@ -304,3 +304,42 @@ export function omitTemporaryIdentifiers<T>(object: Readonly<T>): T {
 
   return objectCopy;
 }
+
+/**
+ * Placeholder emails that ship with the default grafana-default-email contact point.
+ * These should not trigger actual email sends or throw errors.
+ */
+const PLACEHOLDER_EMAILS = ['<example@email.com>', 'example@email.com'];
+
+/**
+ * Check if a single channel/integration has placeholder email addresses.
+ * Used in UI components to disable test buttons and show warnings.
+ */
+export function hasPlaceholderEmail(channelValues?: GrafanaChannelValues): boolean {
+  if (!channelValues || channelValues.type !== 'email') {
+    return false;
+  }
+  const addresses = channelValues.settings?.addresses;
+  if (!addresses) {
+    return false;
+  }
+  const addressList = typeof addresses === 'string' ? [addresses] : addresses;
+  return addressList.some((addr: string) => PLACEHOLDER_EMAILS.includes(addr?.trim()));
+}
+
+/**
+ * Check if any receiver in a list has placeholder email addresses.
+ * Used in actions to determine if warning messages should be shown.
+ */
+export function receiverHasPlaceholderEmail(receivers: Receiver[]): boolean {
+  return receivers.some((receiver) =>
+    receiver.grafana_managed_receiver_configs?.some((config) => {
+      if (config.type === 'email' && config.settings?.addresses) {
+        const addresses = config.settings.addresses;
+        const addressList = typeof addresses === 'string' ? [addresses] : addresses;
+        return addressList.some((addr: string) => PLACEHOLDER_EMAILS.includes(addr.trim()));
+      }
+      return false;
+    })
+  );
+}