test: ut for fileLocking

test/unit/util/fileLockingTest.ts

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+/*
+ * Copyright (c) 2023, salesforce.com, inc.
+ * All rights reserved.
+ * Licensed under the BSD 3-Clause license.
+ * For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
+ */
+import { join } from 'node:path';
+import * as fs from 'node:fs';
+import { tmpdir } from 'node:os';
+import { expect } from 'chai';
+import { lockInit, lockInitSync } from '../../../src/util/fileLocking';
+import { uniqid } from '../../../src/util/uniqid';
+
+describe('fileLocking', () => {
+  describe('lockInit', () => {
+    const targetFolder = join(tmpdir(), uniqid('fileLockingTest'));
+    const file1 = join(targetFolder, 'file1.txt');
+
+    it('should create a dir and lock the directory if the file does not exist', async () => {
+      const lock = await lockInit(file1);
+      await lock.unlock();
+      expect(fs.existsSync(targetFolder)).to.be.true;
+      expect(fs.existsSync(file1)).to.be.false;
+    });
+    it('should write to locked file that does not exist', async () => {
+      const lock = await lockInit(file1);
+      await lock.writeAndUnlock('hey');
+      expect(fs.existsSync(targetFolder)).to.be.true;
+      expect(fs.readFileSync(file1, 'utf8')).to.equal('hey');
+    });
+
+    it('should lock the file if it exists', async () => {
+      const lock = await lockInit(file1);
+      await lock.unlock();
+      expect(fs.readFileSync(file1, 'utf8')).to.equal('hey');
+    });
+
+    it('should write to locked file that does exist', async () => {
+      const lock = await lockInit(file1);
+      await lock.writeAndUnlock('hey, you');
+      expect(fs.readFileSync(file1, 'utf8')).to.equal('hey, you');
+    });
+  });
+
+  describe('lockInitSync', () => {
+    const targetFolder = join(tmpdir(), uniqid('fileLockingTestSync'));
+    const file2 = join(targetFolder, 'file2.txt');
+
+    it('should create a dir and lock the directory if the file does not exist', () => {
+      const lock = lockInitSync(file2);
+      lock.unlock();
+      expect(fs.existsSync(targetFolder)).to.be.true;
+      expect(fs.existsSync(file2)).to.be.false;
+    });
+    it('should write to locked file that does not exist', () => {
+      const lock = lockInitSync(file2);
+      lock.writeAndUnlock('hey');
+      expect(fs.readFileSync(file2, 'utf8')).to.equal('hey');
+    });
+
+    it('should lock the file if it exists', () => {
+      const lock = lockInitSync(file2);
+      lock.unlock();
+      expect(fs.readFileSync(file2, 'utf8')).to.equal('hey');
+    });
+
+    it('should write to locked file that does exist', () => {
+      const lock = lockInitSync(file2);
+      lock.writeAndUnlock('hey, you');
+      expect(fs.readFileSync(file2, 'utf8')).to.equal('hey, you');
+    });
+  });
+
+  describe('validate lock behavior', () => {
+    const targetFolder = join(tmpdir(), uniqid('fileLockingTestConcurrency'));
+    describe('async', () => {
+      it('waits for a lock using writeAndUnlock', async () => {
+        const file3 = join(targetFolder, 'file3.txt');
+        const lock = await lockInit(file3);
+        const [lock2] = await Promise.all([lockInit(file3), lock.writeAndUnlock('hey')]);
+        await lock2.writeAndUnlock('hey, you');
+        expect(fs.readFileSync(file3, 'utf8')).to.equal('hey, you');
+      });
+      it('waits for a lock using unlock', async () => {
+        const file4 = join(targetFolder, 'file3.txt');
+        fs.writeFileSync(file4, 'hey, buddy');
+        const lock = await lockInit(file4);
+        const [lock2] = await Promise.all([lockInit(file4), lock.unlock()]);
+        await lock2.unlock();
+        expect(fs.readFileSync(file4, 'utf8')).to.equal('hey, buddy');
+      });
+    });
+  });
+});