feat(internal): readFile

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

src/internal/__tests__/read-file.spec.ts

@@ -0,0 +1,19 @@
+/**
+ * @file Unit Tests - readFile
+ * @module tsconfig-utils/internal/tests/unit/readFile
+ */
+
+import pathe from '@flex-development/pathe'
+import fs from 'node:fs'
+import { URL, pathToFileURL } from 'node:url'
+import testSubject from '../read-file'
+
+describe('unit:internal/readFile', () => {
+  it('should return file content', () => {
+    // Arrange
+    const id: URL = new URL('tsconfig.json', pathToFileURL('.' + pathe.sep))
+
+    // Act + Expect
+    expect(testSubject(id)).to.equal(fs.readFileSync(id, 'utf8'))
+  })
+})

src/internal/index.ts

@@ -5,6 +5,7 @@
 
 export { default as isDirectory } from './is-directory'
 export { default as isFile } from './is-file'
+export { default as readFile } from './read-file'
 export { default as validateFunction } from './validate-function'
 export { default as validateString } from './validate-string'
 export { default as validateURLString } from './validate-url-string'

src/internal/read-file.ts

@@ -0,0 +1,24 @@
+/**
+ * @file Internal - readFile
+ * @module tsconfig-utils/internal/readFile
+ */
+
+import type { NodeError } from '@flex-development/errnode'
+import fs from 'node:fs'
+import type { URL } from 'node:url'
+import validateURLString from './validate-url-string'
+
+/**
+ * Reads the file at the given module `id`.
+ *
+ * @param {URL | string} id - Module id to evaluate
+ * @return {string} File content at `id`
+ * @throws {NodeError<Error | TypeError>} If `id` is not a string or an instance
+ * of {@linkcode URL}, or if error occurs while reading file
+ */
+const readFile = (id: URL | string): string => {
+  validateURLString(id, 'id')
+  return fs.readFileSync(id, 'utf8')
+}
+
+export default readFile