Clone the file whenever possible

Fixes #27

fs.js

@@ -48,6 +48,14 @@ export const statSync = path => {
 	}
 };
 
+export const lstatSync = path => {
+	try {
+		return fs.statSync(path);
+	} catch (error) {
+		throw new CopyFileError(`stat \`${path}\` failed: ${error.message}`, {cause: error});
+	}
+};
+
 export const utimesSync = (path, atime, mtime) => {
 	try {
 		return fs.utimesSync(path, atime, mtime);

index.d.ts

@@ -79,6 +79,8 @@ Copy a file.
 @param destination - Where you want the file copied.
 @returns A `Promise` that resolves when the file is copied.
 
+The file is cloned if the `onProgress` option is not passed and the [file system supports it](https://stackoverflow.com/a/76496347/64949).
+
 @example
 ```
 import {copyFile} from 'cp-file';
@@ -95,6 +97,8 @@ Copy a file synchronously.
 @param source - The file you want to copy.
 @param destination - Where you want the file copied.
 
+The file is cloned if the [file system supports it](https://stackoverflow.com/a/76496347/64949).
+
 @example
 ```
 import {copyFileSync} from 'cp-file';

index.js

@@ -1,74 +1,25 @@
 import path from 'node:path';
-import {constants as fsConstants} from 'node:fs';
+import realFS, {constants as fsConstants} from 'node:fs';
+import realFSPromises from 'node:fs/promises';
 import {pEvent} from 'p-event';
 import CopyFileError from './copy-file-error.js';
 import * as fs from './fs.js';
 
-const copyFileAsync = async (source, destination, options) => {
-	let readError;
-	const {size} = await fs.stat(source);
+const resolvePath = (cwd, sourcePath, destinationPath) => ({
+	sourcePath: path.resolve(cwd, sourcePath),
+	destinationPath: path.resolve(cwd, destinationPath),
+});
 
-	const readStream = await fs.createReadStream(source);
-	await fs.makeDirectory(path.dirname(destination), {mode: options.directoryMode});
-	const writeStream = fs.createWriteStream(destination, {flags: options.overwrite ? 'w' : 'wx'});
-
-	const emitProgress = writtenBytes => {
-		if (typeof options.onProgress !== 'function') {
-			return;
-		}
-
-		options.onProgress({
-			sourcePath: path.resolve(source),
-			destinationPath: path.resolve(destination),
-			size,
-			writtenBytes,
-			percent: writtenBytes === size ? 1 : writtenBytes / size,
+const checkSourceIsFile = (stat, source) => {
+	if (!stat.isFile()) {
+		throw Object.assign(new CopyFileError(`EISDIR: illegal operation on a directory '${source}'`), {
+			errno: -21,
+			code: 'EISDIR',
+			source,
 		});
-	};
-
-	readStream.on('data', () => {
-		emitProgress(writeStream.bytesWritten);
-	});
-
-	readStream.once('error', error => {
-		readError = new CopyFileError(`Cannot read from \`${source}\`: ${error.message}`, {cause: error});
-	});
-
-	let shouldUpdateStats = false;
-	try {
-		const writePromise = pEvent(writeStream, 'close');
-		readStream.pipe(writeStream);
-		await writePromise;
-		emitProgress(size);
-		shouldUpdateStats = true;
-	} catch (error) {
-		throw new CopyFileError(`Cannot write to \`${destination}\`: ${error.message}`, {cause: error});
-	}
-
-	if (readError) {
-		throw readError;
-	}
-
-	if (shouldUpdateStats) {
-		const stats = await fs.lstat(source);
-
-		return Promise.all([
-			fs.utimes(destination, stats.atime, stats.mtime),
-			fs.chmod(destination, stats.mode),
-		]);
 	}
 };
 
-const resolvePath = (cwd, sourcePath, destinationPath) => {
-	sourcePath = path.resolve(cwd, sourcePath);
-	destinationPath = path.resolve(cwd, destinationPath);
-
-	return {
-		sourcePath,
-		destinationPath,
-	};
-};
-
 export async function copyFile(sourcePath, destinationPath, options = {}) {
 	if (!sourcePath || !destinationPath) {
 		throw new CopyFileError('`source` and `destination` required');
@@ -83,18 +34,74 @@ export async function copyFile(sourcePath, destinationPath, options = {}) {
 		...options,
 	};
 
-	return copyFileAsync(sourcePath, destinationPath, options);
-}
+	const stats = await fs.lstat(sourcePath);
+	const {size} = stats;
+	checkSourceIsFile(stats, sourcePath);
+	await fs.makeDirectory(path.dirname(destinationPath), {mode: options.directoryMode});
+
+	if (typeof options.onProgress === 'function') {
+		const readStream = await fs.createReadStream(sourcePath);
+		const writeStream = fs.createWriteStream(destinationPath, {flags: options.overwrite ? 'w' : 'wx'});
+
+		const emitProgress = writtenBytes => {
+			options.onProgress({
+				sourcePath: path.resolve(sourcePath),
+				destinationPath: path.resolve(destinationPath),
+				size,
+				writtenBytes,
+				percent: writtenBytes === size ? 1 : writtenBytes / size,
+			});
+		};
+
+		readStream.on('data', () => {
+			emitProgress(writeStream.bytesWritten);
+		});
 
-const checkSourceIsFile = (stat, source) => {
-	if (stat.isDirectory()) {
-		throw Object.assign(new CopyFileError(`EISDIR: illegal operation on a directory '${source}'`), {
-			errno: -21,
-			code: 'EISDIR',
-			source,
+		let readError;
+
+		readStream.once('error', error => {
+			readError = new CopyFileError(`Cannot read from \`${sourcePath}\`: ${error.message}`, {cause: error});
 		});
+
+		let shouldUpdateStats = false;
+		try {
+			const writePromise = pEvent(writeStream, 'close');
+			readStream.pipe(writeStream);
+			await writePromise;
+			emitProgress(size);
+			shouldUpdateStats = true;
+		} catch (error) {
+			throw new CopyFileError(`Cannot write to \`${destinationPath}\`: ${error.message}`, {cause: error});
+		}
+
+		if (readError) {
+			throw readError;
+		}
+
+		if (shouldUpdateStats) {
+			const stats = await fs.lstat(sourcePath);
+
+			return Promise.all([
+				fs.utimes(destinationPath, stats.atime, stats.mtime),
+				fs.chmod(destinationPath, stats.mode),
+			]);
+		}
+	} else {
+		// eslint-disable-next-line no-bitwise
+		const flags = options.overwrite ? fsConstants.COPYFILE_FICLONE : (fsConstants.COPYFILE_FICLONE | fsConstants.COPYFILE_EXCL);
+
+		try {
+			await realFSPromises.copyFile(sourcePath, destinationPath, flags);
+
+			await Promise.all([
+				realFSPromises.utimes(destinationPath, stats.atime, stats.mtime),
+				realFSPromises.chmod(destinationPath, stats.mode),
+			]);
+		} catch (error) {
+			throw new CopyFileError(error.message, {cause: error});
+		}
 	}
-};
+}
 
 export function copyFileSync(sourcePath, destinationPath, options = {}) {
 	if (!sourcePath || !destinationPath) {
@@ -110,20 +117,18 @@ export function copyFileSync(sourcePath, destinationPath, options = {}) {
 		...options,
 	};
 
-	const stat = fs.statSync(sourcePath);
-	checkSourceIsFile(stat, sourcePath);
+	const stats = fs.lstatSync(sourcePath);
+	checkSourceIsFile(stats, sourcePath);
 	fs.makeDirectorySync(path.dirname(destinationPath), {mode: options.directoryMode});
 
-	const flags = options.overwrite ? null : fsConstants.COPYFILE_EXCL;
+	// eslint-disable-next-line no-bitwise
+	const flags = options.overwrite ? fsConstants.COPYFILE_FICLONE : (fsConstants.COPYFILE_FICLONE | fsConstants.COPYFILE_EXCL);
 	try {
-		fs.copyFileSync(sourcePath, destinationPath, flags);
+		realFS.copyFileSync(sourcePath, destinationPath, flags);
 	} catch (error) {
-		if (!options.overwrite && error.code === 'EEXIST') {
-			return;
-		}
-
-		throw error;
+		throw new CopyFileError(error.message, {cause: error});
 	}
 
-	fs.utimesSync(destinationPath, stat.atime, stat.mtime);
+	fs.utimesSync(destinationPath, stats.atime, stats.mtime);
+	fs.chmod(destinationPath, stats.mode);
 }

readme.md

@@ -4,7 +4,7 @@
 
 ## Highlights
 
-- Fast by using streams in the async version and [`fs.copyFileSync()`](https://nodejs.org/api/fs.html#fs_fs_copyfilesync_src_dest_flags) in the synchronous version.
+- It's super fast by [cloning](https://stackoverflow.com/questions/71629903/node-js-why-we-should-use-copyfile-ficlone-and-copyfile-ficlone-force-what-is) the file whenever possible.
 - Resilient by using [graceful-fs](https://github.com/isaacs/node-graceful-fs).
 - User-friendly by creating non-existent destination directories for you.
 - Can be safe by turning off [overwriting](#overwrite).
@@ -32,6 +32,8 @@ console.log('File copied');
 
 Returns a `Promise` that resolves when the file is copied.
 
+The file is cloned if the `onProgress` option is not passed and the [file system supports it](https://stackoverflow.com/a/76496347/64949).
+
 ### copyFileSync(source, destination, options?)
 
 #### source
@@ -40,6 +42,8 @@ Type: `string`
 
 The file you want to copy.
 
+The file is cloned if the [file system supports it](https://stackoverflow.com/a/76496347/64949).
+
 #### destination
 
 Type: `string`

test/async.js

@@ -111,16 +111,11 @@ test('do not create `destination` on unreadable `source`', async t => {
 });
 
 test('do not create `destination` directory on unreadable `source`', async t => {
-	const error = await t.throwsAsync(copyFile('node_modules', path.join('subdir', crypto.randomUUID())));
+	const error = await t.throwsAsync(copyFile('node_modules', path.join('temp/subdir', crypto.randomUUID())));
 
 	t.is(error.name, 'CopyFileError', error.message);
 	t.is(error.code, 'EISDIR', error.message);
-
-	t.throws(() => {
-		fs.statSync('subdir');
-	}, {
-		message: /ENOENT/,
-	});
+	t.false(fs.existsSync('subdir'));
 });
 
 test('preserve timestamps', async t => {

test/sync.js

@@ -83,7 +83,14 @@ test('overwrite when options are undefined', t => {
 
 test('do not overwrite when disabled', t => {
 	fs.writeFileSync(t.context.destination, '');
-	copyFileSync('license', t.context.destination, {overwrite: false});
+
+	const error = t.throws(() => {
+		copyFileSync('license', t.context.destination, {overwrite: false});
+	}, {
+		name: 'CopyFileError',
+	});
+
+	t.is(error.code, 'EEXIST');
 	t.is(fs.readFileSync(t.context.destination, 'utf8'), '');
 });
 
@@ -178,7 +185,7 @@ test.failing('rethrow mkdir EACCES errors', t => {
 	fs.mkdirSync.restore();
 });
 
-test.failing('rethrow ENOSPC errors', t => {
+test('rethrow ENOSPC errors', t => {
 	const noSpaceError = buildENOSPC();
 
 	fs.writeFileSync(t.context.source, '');