From ce4ac15850d3f8596de1ac78701e899f21019165 Mon Sep 17 00:00:00 2001
From: Daniil Demidovich <ddemidovich@staply.ru>
Date: Tue, 22 Sep 2020 13:44:58 +0300
Subject: [PATCH] lib: fix readFile flag option typo
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PR-URL: https://github.com/nodejs/node/pull/35292
Reviewed-By: Andrey Pechkurov <apechkurov@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Masashi Hirano <shisama07@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
---
 lib/fs.js                               |  2 +-
 test/parallel/test-fs-readfile-flags.js | 51 +++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-fs-readfile-flags.js

diff --git a/lib/fs.js b/lib/fs.js
index c570a8c9f4fc2e..8e26339e215c89 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -322,7 +322,7 @@ function readFile(path, options, callback) {
     return;
   }
 
-  const flagsNumber = stringToFlags(options.flags);
+  const flagsNumber = stringToFlags(options.flag);
   path = getValidatedPath(path);
 
   const req = new FSReqCallback();
diff --git a/test/parallel/test-fs-readfile-flags.js b/test/parallel/test-fs-readfile-flags.js
new file mode 100644
index 00000000000000..2aceee25506419
--- /dev/null
+++ b/test/parallel/test-fs-readfile-flags.js
@@ -0,0 +1,51 @@
+'use strict';
+
+// Test of fs.readFile with different flags.
+const common = require('../common');
+const fs = require('fs');
+const assert = require('assert');
+const path = require('path');
+const tmpdir = require('../common/tmpdir');
+
+tmpdir.refresh();
+
+{
+  const emptyFile = path.join(tmpdir.path, 'empty.txt');
+  fs.closeSync(fs.openSync(emptyFile, 'w'));
+
+  fs.readFile(
+    emptyFile,
+    // With `a+` the file is created if it does not exist
+    { encoding: 'utf8', flag: 'a+' },
+    common.mustCall((err, data) => { assert.strictEqual(data, ''); })
+  );
+
+  fs.readFile(
+    emptyFile,
+    // Like `a+` but fails if the path exists.
+    { encoding: 'utf8', flag: 'ax+' },
+    common.mustCall((err, data) => { assert.strictEqual(err.code, 'EEXIST'); })
+  );
+}
+
+{
+  const willBeCreated = path.join(tmpdir.path, 'will-be-created');
+
+  fs.readFile(
+    willBeCreated,
+    // With `a+` the file is created if it does not exist
+    { encoding: 'utf8', flag: 'a+' },
+    common.mustCall((err, data) => { assert.strictEqual(data, ''); })
+  );
+}
+
+{
+  const willNotBeCreated = path.join(tmpdir.path, 'will-not-be-created');
+
+  fs.readFile(
+    willNotBeCreated,
+    // Default flag is `r`. An exception occurs if the file does not exist.
+    { encoding: 'utf8' },
+    common.mustCall((err, data) => { assert.strictEqual(err.code, 'ENOENT'); })
+  );
+}