Add weekly PR statistics GitHub Action

.github/workflows/pr-statistics.yml

@@ -0,0 +1,55 @@
+name: PR Statistics Report
+run-name: Generate weekly PR statistics and send to Slack
+
+on:
+  schedule:
+    # Every Monday at 8am GMT
+    - cron: '0 8 * * 1'
+  workflow_dispatch:
+    # Allow manual triggering for testing
+
+jobs:
+  generate-pr-statistics:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Generate App Token
+        id: generate-token
+        uses: tibdex/github-app-token@v2
+        with:
+          app_id: ${{ secrets.LE_BOT_APP_ID }}
+          private_key: ${{ secrets.LE_BOT_PRIVATE_KEY }}
+
+      - name: Checkout .github repository
+        uses: actions/checkout@v4
+        with:
+          repository: learningequality/.github
+          ref: main
+          token: ${{ steps.generate-token.outputs.token }}
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Generate PR statistics
+        id: stats
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ steps.generate-token.outputs.token }}
+          script: |
+            const script = require('./scripts/pr-statistics.js');
+            return await script({github, context, core});
+
+      - name: Send Slack notification
+        if: ${{ steps.stats.outputs.slack_message }}
+        uses: slackapi/slack-github-action@v2.0.0
+        with:
+          webhook-type: incoming-webhook
+          webhook: ${{ secrets.SLACK_PR_STATS_WEBHOOK_URL }}
+          payload: |
+            {
+              "text": ${{ toJSON(steps.stats.outputs.slack_message) }}
+            }

scripts/constants.js

@@ -84,7 +84,17 @@ const BOT_MESSAGE_ALREADY_ASSIGNED = `Hi! 👋 \n\n Thanks so much for your inte
 
 const BOT_MESSAGE_PULL_REQUEST = `👋 Thanks for contributing! \n\n We will assign a reviewer within the next two weeks. In the meantime, please ensure that:\n\n- [ ] **You ran \`pre-commit\` locally**\n- [ ] **All issue requirements are satisfied**\n- [ ] **The contribution is aligned with our [Contributing guidelines](https://learningequality.org/contributing-to-our-open-code-base). Pay extra attention to [Using generative AI](https://learningequality.org/contributing-to-our-open-code-base/#using-generative-ai). Pull requests that don't follow the guidelines will be closed.**\n\nWe'll be in touch! 😊`;
 
-const HOLIDAY_MESSAGE = `Season’s greetings! 👋 \n\n We’d like to thank everyone for another year of fruitful collaborations, engaging discussions, and for the continued support of our work. **Learning Equality will be on holidays from December 22 to January 5.** We look forward to much more in the new year and wish you a very happy holiday season!${GSOC_NOTE}`;
+const HOLIDAY_MESSAGE = `Season's greetings! 👋 \n\n We'd like to thank everyone for another year of fruitful collaborations, engaging discussions, and for the continued support of our work. **Learning Equality will be on holidays from December 22 to January 5.** We look forward to much more in the new year and wish you a very happy holiday season!${GSOC_NOTE}`;
+
+// Repositories to include in PR statistics reports
+const PR_STATS_REPOS = [
+  'kolibri',
+  'studio',
+  'kolibri-design-system',
+  'le-utils',
+  '.github',
+  'ricecooker',
+];
 
 module.exports = {
   LE_BOT_USERNAME,
@@ -98,4 +108,5 @@ module.exports = {
   BOT_MESSAGE_PULL_REQUEST,
   TEAMS_WITH_CLOSE_CONTRIBUTORS,
   HOLIDAY_MESSAGE,
+  PR_STATS_REPOS,
 };

scripts/pr-statistics.js

@@ -0,0 +1,286 @@
+const { PR_STATS_REPOS } = require('./constants');
+
+const ORG = 'learningequality';
+const ROLLING_WINDOW_DAYS = 30;
+
+/**
+ * Calculate percentile value from a sorted array of numbers.
+ * Uses linear interpolation between closest ranks.
+ */
+function percentile(sortedArr, p) {
+  if (sortedArr.length === 0) return null;
+  if (sortedArr.length === 1) return sortedArr[0];
+
+  const index = (p / 100) * (sortedArr.length - 1);
+  const lower = Math.floor(index);
+  const upper = Math.ceil(index);
+  const weight = index - lower;
+
+  if (upper >= sortedArr.length) return sortedArr[sortedArr.length - 1];
+  return sortedArr[lower] * (1 - weight) + sortedArr[upper] * weight;
+}
+
+/**
+ * Format milliseconds into human-readable duration.
+ */
+function formatDuration(ms) {
+  if (ms === null || ms === undefined) return 'N/A';
+
+  const seconds = Math.floor(ms / 1000);
+  const minutes = Math.floor(seconds / 60);
+  const hours = Math.floor(minutes / 60);
+  const days = Math.floor(hours / 24);
+
+  if (days > 0) {
+    const remainingHours = hours % 24;
+    if (remainingHours > 0) {
+      return `${days}d ${remainingHours}h`;
+    }
+    return `${days}d`;
+  }
+
+  if (hours > 0) {
+    const remainingMinutes = minutes % 60;
+    if (remainingMinutes > 0) {
+      return `${hours}h ${remainingMinutes}m`;
+    }
+    return `${hours}h`;
+  }
+
+  if (minutes > 0) {
+    return `${minutes}m`;
+  }
+
+  return '<1m';
+}
+
+/**
+ * Fetch all PRs for a repository updated within the rolling window.
+ */
+async function fetchPRsForRepo(github, owner, repo, sinceDate) {
+  const prs = [];
+  let page = 1;
+  const perPage = 100;
+
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    try {
+      const response = await github.rest.pulls.list({
+        owner,
+        repo,
+        state: 'all',
+        sort: 'updated',
+        direction: 'desc',
+        per_page: perPage,
+        page,
+      });
+
+      if (response.data.length === 0) break;
+
+      // Filter PRs updated within the rolling window
+      const relevantPRs = response.data.filter(pr => new Date(pr.updated_at) >= sinceDate);
+
+      prs.push(...relevantPRs);
+
+      // If we got fewer PRs than requested or all remaining PRs are outside window, stop
+      if (response.data.length < perPage) break;
+
+      // If the last PR in this page is outside our window, we can stop
+      const lastPR = response.data[response.data.length - 1];
+      if (new Date(lastPR.updated_at) < sinceDate) break;
+
+      page++;
+    } catch (error) {
+      // eslint-disable-next-line no-console
+      console.error(`Error fetching PRs for ${owner}/${repo} page ${page}:`, error.message);
+      break;
+    }
+  }
+
+  return prs;
+}
+
+/**
+ * Fetch reviews for a PR and return the first review timestamp.
+ */
+async function getFirstReviewTime(github, owner, repo, pullNumber) {
+  try {
+    const response = await github.rest.pulls.listReviews({
+      owner,
+      repo,
+      pull_number: pullNumber,
+      per_page: 100,
+    });
+
+    if (response.data.length === 0) return null;
+
+    // Find the earliest review
+    const reviewTimes = response.data
+      .filter(review => review.submitted_at)
+      .map(review => new Date(review.submitted_at).getTime());
+
+    if (reviewTimes.length === 0) return null;
+
+    return Math.min(...reviewTimes);
+  } catch (error) {
+    // eslint-disable-next-line no-console
+    console.error(`Error fetching reviews for ${owner}/${repo}#${pullNumber}:`, error.message);
+    return null;
+  }
+}
+
+/**
+ * Main function to calculate PR statistics.
+ */
+module.exports = async ({ github, core }) => {
+  const now = new Date();
+  const sinceDate = new Date(now.getTime() - ROLLING_WINDOW_DAYS * 24 * 60 * 60 * 1000);
+
+  // eslint-disable-next-line no-console
+  console.log(`Calculating PR statistics for ${ROLLING_WINDOW_DAYS}-day rolling window`);
+  // eslint-disable-next-line no-console
+  console.log(`Since: ${sinceDate.toISOString()}`);
+  // eslint-disable-next-line no-console
+  console.log(`Repositories: ${PR_STATS_REPOS.join(', ')}`);
+
+  // Collect all time-to-first-review values (in milliseconds)
+  const timeToFirstReviewValues = [];
+
+  // Collect all PR lifespan values for closed/merged PRs (in milliseconds)
+  const lifespanValues = [];
+
+  // Count open PRs without reviews
+  const openUnreviewedPRs = [];
+
+  // Track totals for reporting
+  let totalPRsProcessed = 0;
+  let totalReviewedPRs = 0;
+  let totalClosedPRs = 0;
+
+  for (const repo of PR_STATS_REPOS) {
+    // eslint-disable-next-line no-console
+    console.log(`\nProcessing ${ORG}/${repo}...`);
+
+    const prs = await fetchPRsForRepo(github, ORG, repo, sinceDate);
+    // eslint-disable-next-line no-console
+    console.log(`  Found ${prs.length} PRs updated in rolling window`);
+
+    for (const pr of prs) {
+      totalPRsProcessed++;
+      const prCreatedAt = new Date(pr.created_at).getTime();
+
+      // Get first review time
+      const firstReviewTime = await getFirstReviewTime(github, ORG, repo, pr.number);
+
+      if (pr.state === 'open') {
+        // Check if open PR has no reviews
+        if (firstReviewTime === null) {
+          openUnreviewedPRs.push({
+            repo,
+            number: pr.number,
+            title: pr.title,
+            url: pr.html_url,
+            createdAt: pr.created_at,
+          });
+        } else {
+          // Open PR with review - calculate time to first review
+          const timeToReview = firstReviewTime - prCreatedAt;
+          if (timeToReview >= 0) {
+            timeToFirstReviewValues.push(timeToReview);
+            totalReviewedPRs++;
+          }
+        }
+      } else {
+        // Closed or merged PR
+        const prClosedAt = new Date(pr.closed_at).getTime();
+        const lifespan = prClosedAt - prCreatedAt;
+
+        if (lifespan >= 0) {
+          lifespanValues.push(lifespan);
+          totalClosedPRs++;
+        }
+
+        // If it had a review, calculate time to first review
+        if (firstReviewTime !== null) {
+          const timeToReview = firstReviewTime - prCreatedAt;
+          if (timeToReview >= 0) {
+            timeToFirstReviewValues.push(timeToReview);
+            totalReviewedPRs++;
+          }
+        }
+      }
+    }
+  }
+
+  // Sort arrays for percentile calculations
+  timeToFirstReviewValues.sort((a, b) => a - b);
+  lifespanValues.sort((a, b) => a - b);
+
+  // Calculate statistics
+  const timeToReviewMedian = percentile(timeToFirstReviewValues, 50);
+  const timeToReviewP95 = percentile(timeToFirstReviewValues, 95);
+
+  const lifespanMedian = percentile(lifespanValues, 50);
+  const lifespanP95 = percentile(lifespanValues, 95);
+
+  // eslint-disable-next-line no-console
+  console.log('\n--- Statistics ---');
+  // eslint-disable-next-line no-console
+  console.log(`Total PRs processed: ${totalPRsProcessed}`);
+  // eslint-disable-next-line no-console
+  console.log(`Reviewed PRs: ${totalReviewedPRs}`);
+  // eslint-disable-next-line no-console
+  console.log(`Closed/Merged PRs: ${totalClosedPRs}`);
+  // eslint-disable-next-line no-console
+  console.log(`Open unreviewed PRs: ${openUnreviewedPRs.length}`);
+  // eslint-disable-next-line no-console
+  console.log(`Time to first review - Median: ${formatDuration(timeToReviewMedian)}, P95: ${formatDuration(timeToReviewP95)}`);
+  // eslint-disable-next-line no-console
+  console.log(`PR lifespan - Median: ${formatDuration(lifespanMedian)}, P95: ${formatDuration(lifespanP95)}`);
+
+  // Format date for report
+  const reportDate = now.toLocaleDateString('en-US', {
+    weekday: 'short',
+    month: 'short',
+    day: 'numeric',
+    year: 'numeric',
+  });
+
+  // Build Slack message
+  let slackMessage = `*Weekly PR Statistics Report*\n`;
+  slackMessage += `_${ROLLING_WINDOW_DAYS}-day rolling window | Generated ${reportDate}_\n\n`;
+
+  slackMessage += `*Time to First Review*\n`;
+  if (timeToFirstReviewValues.length > 0) {
+    slackMessage += `Median: ${formatDuration(timeToReviewMedian)} | 95th percentile: ${formatDuration(timeToReviewP95)}\n`;
+    slackMessage += `_Based on ${totalReviewedPRs} reviewed PRs_\n\n`;
+  } else {
+    slackMessage += `_No reviewed PRs in this period_\n\n`;
+  }
+
+  slackMessage += `*PR Lifespan (Open to Close/Merge)*\n`;
+  if (lifespanValues.length > 0) {
+    slackMessage += `Median: ${formatDuration(lifespanMedian)} | 95th percentile: ${formatDuration(lifespanP95)}\n`;
+    slackMessage += `_Based on ${totalClosedPRs} closed/merged PRs_\n\n`;
+  } else {
+    slackMessage += `_No closed PRs in this period_\n\n`;
+  }
+
+  slackMessage += `*Open Unreviewed PRs*\n`;
+  if (openUnreviewedPRs.length > 0) {
+    slackMessage += `${openUnreviewedPRs.length} PR${openUnreviewedPRs.length === 1 ? '' : 's'} awaiting first review\n`;
+  } else {
+    slackMessage += `All open PRs have been reviewed\n`;
+  }
+
+  slackMessage += `\n_Repos: ${PR_STATS_REPOS.join(', ')}_`;
+
+  // Set outputs
+  core.setOutput('slack_message', slackMessage);
+  core.setOutput('total_prs', totalPRsProcessed);
+  core.setOutput('reviewed_prs', totalReviewedPRs);
+  core.setOutput('closed_prs', totalClosedPRs);
+  core.setOutput('open_unreviewed_prs', openUnreviewedPRs.length);
+
+  return slackMessage;
+};