test: improve test coverage of fs.ReadStream with FileHandle

test/parallel/test-fs-read-stream-file-handle.js

@@ -7,14 +7,14 @@ const tmpdir = require('../common/tmpdir');
 const file = path.join(tmpdir.path, 'read_stream_filehandle_test.txt');
 const input = 'hello world';
 
-let output = '';
 tmpdir.refresh();
 fs.writeFileSync(file, input);
 
-fs.promises.open(file, 'r').then(common.mustCall((handle) => {
+fs.promises.open(file, 'r').then((handle) => {
   handle.on('close', common.mustCall());
   const stream = fs.createReadStream(null, { fd: handle });
 
+  let output = '';
   stream.on('data', common.mustCallAtLeast((data) => {
     output += data;
   }));
@@ -24,42 +24,60 @@ fs.promises.open(file, 'r').then(common.mustCall((handle) => {
   }));
 
   stream.on('close', common.mustCall());
-}));
+}).then(common.mustCall());
 
-fs.promises.open(file, 'r').then(common.mustCall((handle) => {
+fs.promises.open(file, 'r').then((handle) => {
   handle.on('close', common.mustCall());
   const stream = fs.createReadStream(null, { fd: handle });
   stream.on('data', common.mustNotCall());
   stream.on('close', common.mustCall());
 
-  handle.close();
-}));
+  return handle.close();
+}).then(common.mustCall());
 
-fs.promises.open(file, 'r').then(common.mustCall((handle) => {
+fs.promises.open(file, 'r').then((handle) => {
   handle.on('close', common.mustCall());
   const stream = fs.createReadStream(null, { fd: handle });
   stream.on('close', common.mustCall());
 
   stream.on('data', common.mustCall(() => {
     handle.close();
   }));
-}));
+}).then(common.mustCall());
 
-fs.promises.open(file, 'r').then(common.mustCall((handle) => {
+fs.promises.open(file, 'r').then((handle) => {
   handle.on('close', common.mustCall());
   const stream = fs.createReadStream(null, { fd: handle });
   stream.on('close', common.mustCall());
 
   stream.close();
-}));
+}).then(common.mustCall());
 
-fs.promises.open(file, 'r').then(common.mustCall((handle) => {
+fs.promises.open(file, 'r').then((handle) => {
   assert.throws(() => {
     fs.createReadStream(null, { fd: handle, fs });
   }, {
     code: 'ERR_METHOD_NOT_IMPLEMENTED',
     name: 'Error',
     message: 'The FileHandle with fs method is not implemented'
   });
-  handle.close();
-}));
+  return handle.close();
+}).then(common.mustCall());
+
+fs.promises.open(file, 'r').then((handle) => {
+  const { read: originalReadFunction } = handle;
+  handle.read = common.mustCallAtLeast(function read() {
+    return Reflect.apply(originalReadFunction, this, arguments);
+  });
+
+  const stream = fs.createReadStream(null, { fd: handle });
+
+  let output = '';
+  stream.on('data', common.mustCallAtLeast((data) => {
+    output += data;
+  }));
+
+  stream.on('end', common.mustCall(() => {
+    assert.strictEqual(output, input);
+  }));
+}).then(common.mustCall());

test/parallel/test-fs-write-stream-file-handle.js

@@ -9,7 +9,7 @@ const input = 'hello world';
 
 tmpdir.refresh();
 
-fs.promises.open(file, 'w+').then(common.mustCall((handle) => {
+fs.promises.open(file, 'w+').then((handle) => {
   handle.on('close', common.mustCall());
   const stream = fs.createWriteStream(null, { fd: handle });
 
@@ -18,4 +18,27 @@ fs.promises.open(file, 'w+').then(common.mustCall((handle) => {
     const output = fs.readFileSync(file, 'utf-8');
     assert.strictEqual(output, input);
   }));
-}));
+}).then(common.mustCall());
+
+fs.promises.open(file, 'w+').then((handle) => {
+  let calls = 0;
+  const {
+    write: originalWriteFunction,
+    writev: originalWritevFunction
+  } = handle;
+  handle.write = function write() {
+    calls++;
+    return Reflect.apply(originalWriteFunction, this, arguments);
+  };
+  handle.writev = function writev() {
+    calls++;
+    return Reflect.apply(originalWritevFunction, this, arguments);
+  };
+  const stream = fs.createWriteStream(null, { fd: handle });
+
+  stream.end(input);
+  stream.on('close', common.mustCall(() => {
+    assert(calls > 0, 'expected at least one call to fileHandle.write or ' +
+    'fileHandle.writev, got 0');
+  }));
+}).then(common.mustCall());