fix(test): clear and close lmdb after each test suite

jest.config.js

@@ -63,4 +63,5 @@ module.exports = {
   moduleFileExtensions: [`js`, `jsx`, `ts`, `tsx`, `json`],
   setupFiles: [`<rootDir>/.jestSetup.js`],
   setupFilesAfterEnv: [`jest-extended`],
+  testEnvironment: `<rootDir>/jest.environment.ts`,
 }

jest.environment.ts

@@ -0,0 +1,23 @@
+const NodeEnvironment = require(`jest-environment-node`)
+
+class CustomEnvironment extends NodeEnvironment {
+  constructor(config, context) {
+    super(config, context)
+  }
+
+  async teardown(): Promise<void> {
+    // close open lmdbs after running test suite
+    // this prevent dangling open handles that sometimes cause problems
+    // particularly in windows tests (failures to move or delete a db file)
+    if (this.global.__GATSBY_OPEN_ROOT_LMDBS) {
+      for (const rootDb of this.global.__GATSBY_OPEN_ROOT_LMDBS.values()) {
+        await rootDb.clearAsync()
+        await rootDb.close()
+      }
+      this.global.__GATSBY_OPEN_ROOT_LMDBS = undefined
+    }
+    await super.teardown()
+  }
+}
+
+module.exports = CustomEnvironment

packages/gatsby/src/utils/__tests__/cache-lmdb.ts

@@ -12,13 +12,12 @@ describeWhenLMDB(`cache-lmdb`, () => {
   let cache
 
   beforeAll(async () => {
-    const { default: GatsbyCacheLmdb } = await import(`../cache-lmdb`)
-    cache = new GatsbyCacheLmdb({ name: `__test__` }).init()
-    const fileDir = path.join(
-      process.cwd(),
-      `.cache/caches-lmdb-${process.env.JEST_WORKER_ID}`
+    const { default: GatsbyCacheLmdb, resetCache } = await import(
+      `../cache-lmdb`
     )
-    await fs.emptyDir(fileDir)
+
+    await resetCache()
+    cache = new GatsbyCacheLmdb({ name: `__test__` }).init()
   })
 
   it(`it can be instantiated`, () => {

packages/gatsby/src/utils/cache-lmdb.ts

@@ -1,6 +1,6 @@
 import { open, RootDatabase, Database, DatabaseOptions } from "lmdb"
-import fs from "fs-extra"
-import path from "path"
+import * as fs from "fs-extra"
+import * as path from "path"
 
 // Since the regular GatsbyCache saves to "caches" this should be "caches-lmdb"
 const cacheDbFile =
@@ -13,8 +13,16 @@ const cacheDbFile =
       }`
     : `caches-lmdb`
 
+const dbPath = path.join(process.cwd(), `.cache/${cacheDbFile}`)
+
+function getAlreadyOpenedStore(): RootDatabase | undefined {
+  if (!globalThis.__GATSBY_OPEN_ROOT_LMDBS) {
+    globalThis.__GATSBY_OPEN_ROOT_LMDBS = new Map()
+  }
+  return globalThis.__GATSBY_OPEN_ROOT_LMDBS.get(dbPath)
+}
+
 export default class GatsbyCacheLmdb {
-  private static store
   private db: Database | undefined
   private encoding: DatabaseOptions["encoding"]
   public readonly name: string
@@ -44,15 +52,21 @@ export default class GatsbyCacheLmdb {
   }
 
   private static getStore(): RootDatabase {
-    if (!GatsbyCacheLmdb.store) {
-      GatsbyCacheLmdb.store = open({
-        name: `root`,
-        path: path.join(process.cwd(), `.cache/${cacheDbFile}`),
-        compression: true,
-        maxDbs: 200,
-      })
+    let rootDb = getAlreadyOpenedStore()
+    if (rootDb) {
+      return rootDb
     }
-    return GatsbyCacheLmdb.store
+
+    rootDb = open({
+      name: `root`,
+      path: dbPath,
+      compression: true,
+      maxDbs: 200,
+    })
+
+    globalThis.__GATSBY_OPEN_ROOT_LMDBS.set(dbPath, rootDb)
+
+    return rootDb
   }
 
   private getDb(): Database {
@@ -78,3 +92,13 @@ export default class GatsbyCacheLmdb {
     return this.getDb().remove(key) as unknown as Promise<void>
   }
 }
+
+export async function resetCache(): Promise<void> {
+  const store = getAlreadyOpenedStore()
+  if (store) {
+    await store.close()
+    globalThis.__GATSBY_OPEN_ROOT_LMDBS.delete(dbPath)
+  }
+
+  await fs.emptyDir(dbPath)
+}