feat(utils): ignore404

.eslintrc.cjs

@@ -18,6 +18,7 @@ module.exports = {
         skipWords: [
           ...RULES_SPELLCHECKER[1].skipWords,
           'callee',
+          'errno',
           'trext',
           'trextel'
         ]

__tests__/__fixtures__/errno-exception.fixture.ts

@@ -0,0 +1,10 @@
+/**
+ * @file Test Fixture - ErrnoException
+ * @module tests/fixtures/ErrnoException
+ */
+
+const EXCEPTION: NodeJS.ErrnoException = new Error('Test errno message')
+
+EXCEPTION.code = 'ERRNO'
+
+export default EXCEPTION

__tests__/__fixtures__/error.fixture.ts

@@ -0,0 +1,6 @@
+/**
+ * @file Test Fixture - Error
+ * @module tests/fixtures/Error
+ */
+
+export default new Error('Test error message')

src/utils/__tests__/ignore-404.util.functional.spec.ts

@@ -0,0 +1,48 @@
+import ERRNO_EXCEPTION from '@tests/fixtures/errno-exception.fixture'
+import ERROR from '@tests/fixtures/error.fixture'
+import type { Testcase } from '@tests/utils/types'
+import testSubject from '../ignore-404.util'
+
+/**
+ * @file Functional Tests - ignore404
+ * @module trext/utils/tests/functional/ignore404
+ */
+
+describe('functional:utils/ignore404', () => {
+  type Case = Testcase<string | undefined> & {
+    error: Error | NodeJS.ErrnoException
+    throw: 'throw' | 'not throw'
+    state: string
+  }
+
+  const cases: Case[] = [
+    {
+      error: ERROR,
+      expected: undefined,
+      state: 'promise contains Error',
+      throw: 'not throw'
+    },
+    {
+      error: ERRNO_EXCEPTION,
+      expected: ERRNO_EXCEPTION.code,
+      state: 'promise contains NodeJS.ErrnoException',
+      throw: 'throw'
+    }
+  ]
+
+  it.each<Case>(cases)('should $throw if $state', async testcase => {
+    // Arrange
+    const { error, expected } = testcase
+    let exception: NodeJS.ErrnoException | null = null
+
+    // Act
+    try {
+      await testSubject(new Promise((resolve, reject) => reject(error)))
+    } catch (error) {
+      exception = error as NodeJS.ErrnoException
+    }
+
+    // Expect
+    expect(exception?.code).toBe(expected)
+  })
+})

src/utils/ignore-404.util.ts

@@ -0,0 +1,27 @@
+/**
+ * @file Utilities - ignore404
+ * @module trext/utils/ignore404
+ */
+
+/**
+ * Waits for a promise to complete and rejects **only if** an error is thrown
+ * and the error is **not** a missing file or directory error.
+ *
+ * @template T - Data in promise
+ *
+ * @async
+ * @param {Promise<T>} p - Promise to evaluate
+ * @return {Promise<T | null>} Data in promise or null
+ * @throws {NodeJS.ErrnoException}
+ */
+async function ignore404<T extends any>(p: Promise<T>): Promise<T | null> {
+  try {
+    return await p
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error
+  }
+
+  return null
+}
+
+export default ignore404

src/utils/index.ts

@@ -0,0 +1,6 @@
+/**
+ * @file Entry Point - Utilities
+ * @module trext/utils
+ */
+
+export { default as ignore404 } from './ignore-404.util'