Retain UNL validators in purge (#400)

## High Level Overview of Change

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With current logic, if a validator has not participated in the consensus
process for more than a week, it will be removed from the list. This led
to an UNL validator, even though still in the UNL list, got removed by
the logic.
This PR would:
- Retain inactive UNL validators that are still discoverable in the UNL
list in the database, until it got removed from the list.
- Increase the purging period from one week to thirty days.

Resolves #395
Replaces #397

### Type of Change

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Please check relevant options, delete irrelevant ones.
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- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (non-breaking change that only restructures code)
- [ ] Tests (You added tests for code that already exists, or your new
feature included in this PR)
- [ ] Documentation Updates
- [ ] Release

Author: pdp2121

src/connection-manager/manifests.ts

@@ -244,16 +244,20 @@ async function updateRevocations(): Promise<void> {
 }
 
 /**
- * Deletes validators that are older than an hour.
+ * Deletes validators that are older than 30 days.
+ * UNL validators are not deleted even if they are older than 30 days.
  *
  * @returns Void.
  */
-async function purgeOldValidators(): Promise<void> {
-  const oneWeekAgo = new Date()
-  oneWeekAgo.setDate(oneWeekAgo.getDate() - 7)
+export async function purgeOldValidators(): Promise<void> {
+  const thirtyDaysAgo = new Date()
+  thirtyDaysAgo.setDate(thirtyDaysAgo.getDate() - 30)
   log.info('Deleting old validators')
   try {
-    await query('validators').where('last_ledger_time', '<', oneWeekAgo).del()
+    await query('validators')
+      .where('last_ledger_time', '<', thirtyDaysAgo)
+      .whereNull('unl')
+      .del()
   } catch (err) {
     log.error(`Error purging old validators`, err)
   }

test/manifests/manifests.test.ts

@@ -5,6 +5,7 @@ import {
   updateManifestsFromRippled,
   updateUNLManifests,
   updateUnls,
+  purgeOldValidators,
 } from '../../src/connection-manager/manifests'
 import {
   destroy,
@@ -194,4 +195,95 @@ describe('manifest ingest', () => {
       unl: null,
     })
   })
+
+  test('purgeOldValidators - purges validator older than 30 days', async () => {
+    const thirtyOneDaysAgo = new Date()
+    thirtyOneDaysAgo.setDate(thirtyOneDaysAgo.getDate() - 31)
+
+    await query('validators').insert({
+      signing_key: 'n9OldValidator1111111111111111111111111111111111111111111',
+      master_key: 'nHOldValidator1111111111111111111111111111111111111111111',
+      last_ledger_time: thirtyOneDaysAgo,
+    })
+
+    // Verify validator exists before purge
+    let validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    expect(validators).toHaveLength(1)
+
+    // Run purge
+    await purgeOldValidators()
+
+    // Verify validator was deleted
+    validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    expect(validators).toHaveLength(0)
+  })
+
+  test('purgeOldValidators - keeps UNL validator even if older than 30 days', async () => {
+    const thirtyOneDaysAgo = new Date()
+    thirtyOneDaysAgo.setDate(thirtyOneDaysAgo.getDate() - 31)
+
+    // Insert a validator that matches the UNL (from unl1 fixture)
+    await query('validators').insert({
+      signing_key: 'n9LCf7NtwcyXVc5fYB6UVByRoQZqJDhrMUoKnr3GQB6mFqpcmMzg',
+      master_key: 'nHBtDzdRDykxiuv7uSMPTcGexNm879RUUz5GW4h1qgjbtyvWZ1LE',
+      unl: 'vl.ripple.com',
+      last_ledger_time: thirtyOneDaysAgo,
+    })
+
+    // Verify validator exists before purge
+    let validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    expect(validators.length).toBeGreaterThanOrEqual(1)
+
+    // Run purge
+    await purgeOldValidators()
+
+    // Verify UNL validator was NOT deleted
+    validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    const unlValidator = validators.find(
+      (validator) =>
+        validator.signing_key ===
+        'n9LCf7NtwcyXVc5fYB6UVByRoQZqJDhrMUoKnr3GQB6mFqpcmMzg',
+    )
+    expect(unlValidator).toBeDefined()
+    expect(unlValidator?.signing_key).toBe(
+      'n9LCf7NtwcyXVc5fYB6UVByRoQZqJDhrMUoKnr3GQB6mFqpcmMzg',
+    )
+  })
+
+  test('purgeOldValidators - keeps validator less than 30 days old', async () => {
+    const tenDaysAgo = new Date()
+    tenDaysAgo.setDate(tenDaysAgo.getDate() - 10)
+
+    await query('validators').insert({
+      signing_key: 'n9RecentValidator11111111111111111111111111111111111111111',
+      master_key: 'nHRecentValidator11111111111111111111111111111111111111111',
+      last_ledger_time: tenDaysAgo,
+    })
+
+    // Verify validator exists before purge
+    let validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    expect(validators).toHaveLength(1)
+
+    // Run purge
+    await purgeOldValidators()
+
+    // Verify recent validator was NOT deleted
+    validators = (await query('validators').select('*')) as Array<{
+      signing_key: string
+    }>
+    expect(validators).toHaveLength(1)
+    expect(validators[0].signing_key).toBe(
+      'n9RecentValidator11111111111111111111111111111111111111111',
+    )
+  })
 })