ci: use SLACK_CHANNEL env var for activity notifications (#16323)

# Overview

Updates the activity notifications workflow and action scripts to read
the Slack channel from a `SLACK_CHANNEL` secret rather than hardcoded
constants. Also fixes a bug where step failures were silently swallowed.

## Key Changes

- **Remove `CHANNELS` constants**
- Deleted `src/constants.ts` and its imports from both action modules.
The channel is now read from `process.env.SLACK_CHANNEL`, validated at
startup with a `TypeError` if unset.

- **Add `SLACK_CHANNEL` to workflow env**
- `activity-notifications.yml` now passes `SLACK_CHANNEL: ${{
secrets.SLACK_CHANNEL }}`. This makes the target channel configurable
without code changes.

- **Remove `continue-on-error: true` from both steps**
- Both steps had `continue-on-error: true`, which caused script failures
to be reported as passed at the job level. Removing it surfaces failures
correctly.

## Design Decisions

`SLACK_CHANNEL` accepts either a channel name (e.g. `#payload-dev`) or a
channel ID (e.g. `C1234567890`). Channel ID is recommended since it
stays stable if the channel is renamed.

The `DEBUG` routing logic (which previously switched between
`CHANNELS.DEV` and `CHANNELS.DEBUG`) has been removed along with the
constants. The channel is now set directly via the secret.

Author: denolfe

.github/actions/activity/dist/new-issues/index.js

@@ -2,7 +2,6 @@ import { info, setFailed } from '@actions/core'
 import { getOctokit } from '@actions/github'
 import { WebClient } from '@slack/web-api'
 
-import { CHANNELS } from './constants'
 import { daysAgo } from './lib/utils'
 import { SlimIssue } from './types'
 
@@ -42,9 +41,12 @@ export async function run() {
   try {
     if (!process.env.GITHUB_TOKEN) throw new TypeError('GITHUB_TOKEN not set')
     if (!process.env.SLACK_TOKEN) throw new TypeError('SLACK_TOKEN not set')
+    if (!process.env.SLACK_CHANNEL) throw new TypeError('SLACK_CHANNEL not set')
 
-    const octoClient = getOctokit(process.env.GITHUB_TOKEN)
-    const slackClient = new WebClient(process.env.SLACK_TOKEN)
+    const { GITHUB_TOKEN, SLACK_TOKEN, SLACK_CHANNEL } = process.env
+
+    const octoClient = getOctokit(GITHUB_TOKEN)
+    const slackClient = new WebClient(SLACK_TOKEN)
 
     const { data } = await octoClient.rest.search.issuesAndPullRequests({
       order: 'desc',
@@ -70,7 +72,7 @@ export async function run() {
 
     await slackClient.chat.postMessage({
       text: messageText,
-      channel: process.env.DEBUG === 'true' ? CHANNELS.DEBUG : CHANNELS.DEV,
+      channel: SLACK_CHANNEL,
       icon_emoji: ':github:',
       username: 'GitHub Notifier',
     })

.github/actions/activity/dist/popular-issues/index.js

@@ -2,7 +2,6 @@ import { info, setFailed } from '@actions/core'
 import { getOctokit } from '@actions/github'
 import { WebClient } from '@slack/web-api'
 
-import { CHANNELS } from './constants'
 import { daysAgo } from './lib/utils'
 import { SlimIssue } from './types'
 
@@ -51,9 +50,12 @@ export async function run() {
   try {
     if (!process.env.GITHUB_TOKEN) throw new TypeError('GITHUB_TOKEN not set')
     if (!process.env.SLACK_TOKEN) throw new TypeError('SLACK_TOKEN not set')
+    if (!process.env.SLACK_CHANNEL) throw new TypeError('SLACK_CHANNEL not set')
 
-    const octoClient = getOctokit(process.env.GITHUB_TOKEN)
-    const slackClient = new WebClient(process.env.SLACK_TOKEN)
+    const { GITHUB_TOKEN, SLACK_TOKEN, SLACK_CHANNEL } = process.env
+
+    const octoClient = getOctokit(GITHUB_TOKEN)
+    const slackClient = new WebClient(SLACK_TOKEN)
 
     const { data } = await octoClient.rest.search.issuesAndPullRequests({
       order: 'desc',
@@ -79,7 +81,7 @@ export async function run() {
 
     await slackClient.chat.postMessage({
       text: messageText,
-      channel: process.env.DEBUG === 'true' ? CHANNELS.DEBUG : CHANNELS.DEV,
+      channel: SLACK_CHANNEL,
       icon_emoji: ':github:',
       username: 'GitHub Notifier',
     })

.github/actions/activity/src/constants.ts

@@ -21,11 +21,10 @@ jobs:
         uses: ./.github/actions/setup
       - name: Popular Issues to Slack
         run: node ./.github/actions/activity/dist/popular-issues/index.js
-        continue-on-error: true
       - name: New Issues to Slack
         run: node ./.github/actions/activity/dist/new-issues/index.js
-        continue-on-error: true
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       SLACK_TOKEN: ${{ secrets.SLACK_TOKEN }}
+      SLACK_CHANNEL: ${{ secrets.SLACK_CHANNEL }}
       DEBUG: ${{ github.event.inputs.debug || 'false' }}