From 912d361f848065c878423b17efb7b1ea06fabccc Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Sun, 4 Jul 2021 18:10:20 -0700
Subject: [PATCH] tools: add find-inactive-collaborators.js

The plan is to eventually call this script with a scheduled GitHub
Action that could automatically open pull requests to move collaborators
to emeritus status after (for example) a year of inactivity.

Sample run:

```
$ node tools/find-inactive-collaborators.mjs '30 months ago'
864 authors have made commits since 30 months ago.
101 landers have landed commits since 30 months ago.
146 reviewers have approved landed commits since 30 months ago.
109 collaborators currently in the project.

Inactive collaborators:

Thomas Watson
$
```
---
 tools/find-inactive-collaborators.mjs | 89 +++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100755 tools/find-inactive-collaborators.mjs

diff --git a/tools/find-inactive-collaborators.mjs b/tools/find-inactive-collaborators.mjs
new file mode 100755
index 00000000000000..20e8a060cd0899
--- /dev/null
+++ b/tools/find-inactive-collaborators.mjs
@@ -0,0 +1,89 @@
+#!/usr/bin/env node
+
+// Identify inactive collaborators. "Inactive" is not quite right, as the things
+// this checks for are not the entirety of collaborator activities. Still, it is
+// a pretty good proxy. Feel free to suggest or implement further metrics.
+
+import cp from 'node:child_process';
+import fs from 'node:fs';
+import readline from 'node:readline';
+
+const SINCE = process.argv[2] || '6 months ago';
+
+async function runGitCommand(cmd, mapFn) {
+  const childProcess = cp.spawn('/bin/sh', ['-c', cmd], {
+    cwd: new URL('..', import.meta.url),
+    encoding: 'utf8',
+    stdio: ['inherit', 'pipe', 'inherit'],
+  });
+  const lines = readline.createInterface({
+    input: childProcess.stdout,
+  });
+  const errorHandler = new Promise(
+    (_, reject) => childProcess.on('error', reject)
+  );
+  const returnedSet = new Set();
+  await Promise.race([errorHandler, Promise.resolve()]);
+  for await (const line of lines) {
+    await Promise.race([errorHandler, Promise.resolve()]);
+    const val = mapFn(line);
+    if (val) {
+      returnedSet.add(val);
+    }
+  }
+  return Promise.race([errorHandler, Promise.resolve(returnedSet)]);
+}
+
+// Retrieve all commit authors during the time period.
+const authors = await runGitCommand(
+  `git shortlog -n -s --since="${SINCE}"`,
+  (line) => line.trim().split('\t', 2)[1]
+);
+
+// Retrieve all commit landers during the time period.
+const landers = await runGitCommand(
+  `git shortlog -n -s -c --since="${SINCE}"`,
+  (line) => line.trim().split('\t', 2)[1]
+);
+
+// Retrieve all approving reviewers of landed commits during the time period.
+const approvingReviewers = await runGitCommand(
+  `git log --since="${SINCE}" | egrep "^    Reviewed-By: "`,
+  (line) => /^    Reviewed-By: ([^<]+)/.exec(line)[1].trim()
+);
+
+// Retrieve list of current collaborators from README.md.
+const readmeText = fs.readFileSync(
+  new URL('../README.md', import.meta.url),
+  'utf8'
+);
+let processingCollaborators = false;
+const collaborators = readmeText
+  .split('\n')
+  .filter((line) => {
+    const isCollaborator = processingCollaborators && line.length;
+    if (line === '### Collaborators') {
+      processingCollaborators = true;
+    }
+    if (line === '### Collaborator emeriti') {
+      processingCollaborators = false;
+    }
+    return line.startsWith('**') && isCollaborator;
+  })
+  .map((line) => line.split('**')[1].trim());
+
+console.log(`${authors.size.toLocaleString()} authors have made commits since ${SINCE}.`);
+console.log(`${landers.size.toLocaleString()} landers have landed commits since ${SINCE}.`);
+console.log(`${approvingReviewers.size.toLocaleString()} reviewers have approved landed commits since ${SINCE}.`);
+console.log(`${collaborators.length.toLocaleString()} collaborators currently in the project.`);
+
+const inactive = collaborators.filter((collaborator) =>
+  !authors.has(collaborator) &&
+  !landers.has(collaborator) &&
+  !approvingReviewers.has(collaborator)
+);
+
+if (inactive.length) {
+  console.log('\nInactive collaborators:');
+  console.log(inactive.join('\n'));
+}