From f5a462f4a8ba223af1e924577617431bae902c86 Mon Sep 17 00:00:00 2001
From: Unknown <bdistin@gmail.com>
Date: Wed, 9 May 2018 11:48:30 -0500
Subject: [PATCH 1/4] fs/promises: ensure options.flag is defaulted to 'r' in
 readFile

When passing {} or { encoding: 'utf8' } as options to readFile, the
flag is not defaulted to 'r' unlike normal fs. This fix makes
(fs/promises).readFile() act consistently with fs.readFile().
---
 lib/internal/fs/promises.js                     |  3 ++-
 .../parallel/test-fs-promises-readfile-empty.js | 17 +++++++++++++++++
 test/parallel/test-fs-readfile-empty.js         |  4 ++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-fs-promises-readfile-empty.js

diff --git a/lib/internal/fs/promises.js b/lib/internal/fs/promises.js
index 0857fd2ffff506..262aed8f31c36f 100644
--- a/lib/internal/fs/promises.js
+++ b/lib/internal/fs/promises.js
@@ -463,11 +463,12 @@ async function appendFile(path, data, options) {
 
 async function readFile(path, options) {
   options = getOptions(options, { flag: 'r' });
+  const flag = options.flag || 'r';
 
   if (path instanceof FileHandle)
     return readFileHandle(path, options);
 
-  const fd = await open(path, options.flag, 0o666);
+  const fd = await open(path, flag, 0o666);
   return readFileHandle(fd, options).finally(fd.close.bind(fd));
 }
 
diff --git a/test/parallel/test-fs-promises-readfile-empty.js b/test/parallel/test-fs-promises-readfile-empty.js
new file mode 100644
index 00000000000000..ef15a2681123c6
--- /dev/null
+++ b/test/parallel/test-fs-promises-readfile-empty.js
@@ -0,0 +1,17 @@
+'use strict';
+require('../common');
+
+const assert = require('assert');
+const { promises: fs } = require('fs');
+const fixtures = require('../common/fixtures');
+
+const fn = fixtures.path('empty.txt');
+
+fs.readFile(fn)
+  .then(assert.ok);
+
+fs.readFile(fn, 'utf8')
+  .then(assert.strictEqual.bind(this, ''));
+
+fs.readFile(fn, { encoding: 'utf8' })
+  .then(assert.strictEqual.bind(this, ''));
diff --git a/test/parallel/test-fs-readfile-empty.js b/test/parallel/test-fs-readfile-empty.js
index 21f99fc6be24ba..36eccfb1162713 100644
--- a/test/parallel/test-fs-readfile-empty.js
+++ b/test/parallel/test-fs-readfile-empty.js
@@ -38,5 +38,9 @@ fs.readFile(fn, 'utf8', function(err, data) {
   assert.strictEqual('', data);
 });
 
+fs.readFile(fn, { encoding: 'utf8' }, function(err, data) {
+  assert.strictEqual('', data);
+});
+
 assert.ok(fs.readFileSync(fn));
 assert.strictEqual('', fs.readFileSync(fn, 'utf8'));

From 26bce853b4a2ca643b1e80af4da80cdd067f0794 Mon Sep 17 00:00:00 2001
From: Unknown <bdistin@gmail.com>
Date: Sun, 27 May 2018 09:51:46 -0500
Subject: [PATCH 2/4] test: requested change

fail on unhandled rejection
---
 test/parallel/test-fs-promises-readfile-empty.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/parallel/test-fs-promises-readfile-empty.js b/test/parallel/test-fs-promises-readfile-empty.js
index ef15a2681123c6..49e16aca153e65 100644
--- a/test/parallel/test-fs-promises-readfile-empty.js
+++ b/test/parallel/test-fs-promises-readfile-empty.js
@@ -7,6 +7,8 @@ const fixtures = require('../common/fixtures');
 
 const fn = fixtures.path('empty.txt');
 
+common.crashOnUnhandledRejection();
+
 fs.readFile(fn)
   .then(assert.ok);
 

From ca44fc29fd2b7efb11bd6801b2971df6146724a1 Mon Sep 17 00:00:00 2001
From: Unknown <bdistin@gmail.com>
Date: Sun, 27 May 2018 11:07:11 -0500
Subject: [PATCH 3/4] test: fix requested change

common was required, but not assigned to common in order for the requested change to work.
---
 test/parallel/test-fs-promises-readfile-empty.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/parallel/test-fs-promises-readfile-empty.js b/test/parallel/test-fs-promises-readfile-empty.js
index 49e16aca153e65..24c17655c62135 100644
--- a/test/parallel/test-fs-promises-readfile-empty.js
+++ b/test/parallel/test-fs-promises-readfile-empty.js
@@ -1,5 +1,5 @@
 'use strict';
-require('../common');
+const common = require('../common');
 
 const assert = require('assert');
 const { promises: fs } = require('fs');

From 543f29729872befed736ce758fc1d3fff829dadc Mon Sep 17 00:00:00 2001
From: Unknown <bdistin@gmail.com>
Date: Mon, 28 May 2018 09:43:08 -0500
Subject: [PATCH 4/4] fs: return string on empty fs.promises.readFile() when
 encoding provided

fs: return string on empty fs.promises.readfile when encoding provided

fs.promises.readfile() would provide a buffer whenever an empty file
is read, when it should have returned an empty string when encoding
is provided.
---
 lib/internal/fs/promises.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/internal/fs/promises.js b/lib/internal/fs/promises.js
index 262aed8f31c36f..c08900289cc0d7 100644
--- a/lib/internal/fs/promises.js
+++ b/lib/internal/fs/promises.js
@@ -139,7 +139,7 @@ async function readFileHandle(filehandle, options) {
   }
 
   if (size === 0)
-    return Buffer.alloc(0);
+    return options.encoding ? '' : Buffer.alloc(0);
 
   if (size > kMaxLength)
     throw new ERR_FS_FILE_TOO_LARGE(size);