fs: support BigInt in fs.*stat and fs.watchFile

Add the `bigint: true` option to all the `fs.*stat` methods and
`fs.watchFile`.

PR-URL: https://github.com/nodejs/node/pull/20220
Fixes: https://github.com/nodejs/node/issues/12115
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

3 files changed, 209 insertions, 1 deletions

diff --git a/test/parallel/test-fs-stat-bigint.js b/test/parallel/test-fs-stat-bigint.js
new file mode 100644
index 0000000000..4030a06fae
--- /dev/null
+++ b/test/parallel/test-fs-stat-bigint.js
@@ -0,0 +1,145 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const fs = require('fs');
+const promiseFs = require('fs').promises;
+const path = require('path');
+const tmpdir = require('../common/tmpdir');
+const { isDate } = require('util').types;
+
+common.crashOnUnhandledRejection();
+tmpdir.refresh();
+
+const fn = path.join(tmpdir.path, 'test-file');
+fs.writeFileSync(fn, 'test');
+
+let link;
+if (!common.isWindows) {
+  link = path.join(tmpdir.path, 'symbolic-link');
+  fs.symlinkSync(fn, link);
+}
+
+function verifyStats(bigintStats, numStats) {
+  for (const key of Object.keys(numStats)) {
+    const val = numStats[key];
+    if (isDate(val)) {
+      const time = val.getTime();
+      const time2 = bigintStats[key].getTime();
+      assert(
+        Math.abs(time - time2) < 2,
+        `difference of ${key}.getTime() should < 2.\n` +
+        `Number version ${time}, BigInt version ${time2}n`);
+    } else if (key === 'mode') {
+      // eslint-disable-next-line no-undef
+      assert.strictEqual(bigintStats[key], BigInt(val));
+      assert.strictEqual(
+        bigintStats.isBlockDevice(),
+        numStats.isBlockDevice()
+      );
+      assert.strictEqual(
+        bigintStats.isCharacterDevice(),
+        numStats.isCharacterDevice()
+      );
+      assert.strictEqual(
+        bigintStats.isDirectory(),
+        numStats.isDirectory()
+      );
+      assert.strictEqual(
+        bigintStats.isFIFO(),
+        numStats.isFIFO()
+      );
+      assert.strictEqual(
+        bigintStats.isFile(),
+        numStats.isFile()
+      );
+      assert.strictEqual(
+        bigintStats.isSocket(),
+        numStats.isSocket()
+      );
+      assert.strictEqual(
+        bigintStats.isSymbolicLink(),
+        numStats.isSymbolicLink()
+      );
+    } else if (common.isWindows && (key === 'blksize' || key === 'blocks')) {
+      assert.strictEqual(bigintStats[key], undefined);
+      assert.strictEqual(numStats[key], undefined);
+    } else if (Number.isSafeInteger(val)) {
+      // eslint-disable-next-line no-undef
+      assert.strictEqual(bigintStats[key], BigInt(val));
+    } else {
+      assert(
+        Math.abs(Number(bigintStats[key]) - val) < 1,
+        `${key} is not a safe integer, difference should < 1.\n` +
+        `Number version ${val}, BigInt version ${bigintStats[key]}n`);
+    }
+  }
+}
+
+{
+  const bigintStats = fs.statSync(fn, { bigint: true });
+  const numStats = fs.statSync(fn);
+  verifyStats(bigintStats, numStats);
+}
+
+if (!common.isWindows) {
+  const bigintStats = fs.lstatSync(link, { bigint: true });
+  const numStats = fs.lstatSync(link);
+  verifyStats(bigintStats, numStats);
+}
+
+{
+  const fd = fs.openSync(fn, 'r');
+  const bigintStats = fs.fstatSync(fd, { bigint: true });
+  const numStats = fs.fstatSync(fd);
+  verifyStats(bigintStats, numStats);
+  fs.closeSync(fd);
+}
+
+{
+  fs.stat(fn, { bigint: true }, (err, bigintStats) => {
+    fs.stat(fn, (err, numStats) => {
+      verifyStats(bigintStats, numStats);
+    });
+  });
+}
+
+if (!common.isWindows) {
+  fs.lstat(link, { bigint: true }, (err, bigintStats) => {
+    fs.lstat(link, (err, numStats) => {
+      verifyStats(bigintStats, numStats);
+    });
+  });
+}
+
+{
+  const fd = fs.openSync(fn, 'r');
+  fs.fstat(fd, { bigint: true }, (err, bigintStats) => {
+    fs.fstat(fd, (err, numStats) => {
+      verifyStats(bigintStats, numStats);
+      fs.closeSync(fd);
+    });
+  });
+}
+
+(async function() {
+  const bigintStats = await promiseFs.stat(fn, { bigint: true });
+  const numStats = await promiseFs.stat(fn);
+  verifyStats(bigintStats, numStats);
+})();
+
+if (!common.isWindows) {
+  (async function() {
+    const bigintStats = await promiseFs.lstat(link, { bigint: true });
+    const numStats = await promiseFs.lstat(link);
+    verifyStats(bigintStats, numStats);
+  })();
+}
+
+(async function() {
+  const handle = await promiseFs.open(fn, 'r');
+  const bigintStats = await handle.stat({ bigint: true });
+  const numStats = await handle.stat();
+  verifyStats(bigintStats, numStats);
+  await handle.close();
+})();
diff --git a/test/parallel/test-fs-sync-fd-leak.js b/test/parallel/test-fs-sync-fd-leak.js
index e7107546e5..52e40eb390 100644
--- a/test/parallel/test-fs-sync-fd-leak.js
+++ b/test/parallel/test-fs-sync-fd-leak.js
@@ -40,7 +40,7 @@ fs.writeSync = function() {
   throw new Error('BAM');
 };
 
-process.binding('fs').fstat = function(fd, _, ctx) {
+process.binding('fs').fstat = function(fd, bigint, _, ctx) {
   ctx.errno = uv.UV_EBADF;
   ctx.syscall = 'fstat';
 };
diff --git a/test/parallel/test-fs-watchfile-bigint.js b/test/parallel/test-fs-watchfile-bigint.js
new file mode 100644
index 0000000000..89cefd12e0
--- /dev/null
+++ b/test/parallel/test-fs-watchfile-bigint.js
@@ -0,0 +1,63 @@
+'use strict';
+const common = require('../common');
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+
+const tmpdir = require('../common/tmpdir');
+
+const enoentFile = path.join(tmpdir.path, 'non-existent-file');
+const expectedStatObject = new fs.Stats(
+  0n,                                        // dev
+  0n,                                        // mode
+  0n,                                        // nlink
+  0n,                                        // uid
+  0n,                                        // gid
+  0n,                                        // rdev
+  common.isWindows ? undefined : 0n,         // blksize
+  0n,                                        // ino
+  0n,                                        // size
+  common.isWindows ? undefined : 0n,         // blocks
+  0n,                                        // atim_msec
+  0n,                                        // mtim_msec
+  0n,                                        // ctim_msec
+  0n                                         // birthtim_msec
+);
+
+tmpdir.refresh();
+
+// If the file initially didn't exist, and gets created at a later point of
+// time, the callback should be invoked again with proper values in stat object
+let fileExists = false;
+const options = { interval: 0, bigint: true };
+
+const watcher =
+  fs.watchFile(enoentFile, options, common.mustCall((curr, prev) => {
+    if (!fileExists) {
+      // If the file does not exist, all the fields should be zero and the date
+      // fields should be UNIX EPOCH time
+      assert.deepStrictEqual(curr, expectedStatObject);
+      assert.deepStrictEqual(prev, expectedStatObject);
+      // Create the file now, so that the callback will be called back once the
+      // event loop notices it.
+      fs.closeSync(fs.openSync(enoentFile, 'w'));
+      fileExists = true;
+    } else {
+      // If the ino (inode) value is greater than zero, it means that the file
+      // is present in the filesystem and it has a valid inode number.
+      assert(curr.ino > 0n);
+      // As the file just got created, previous ino value should be lesser than
+      // or equal to zero (non-existent file).
+      assert(prev.ino <= 0n);
+      // Stop watching the file
+      fs.unwatchFile(enoentFile);
+      watcher.stop();  // stopping a stopped watcher should be a noop
+    }
+  }, 2));
+
+// 'stop' should only be emitted once - stopping a stopped watcher should
+// not trigger a 'stop' event.
+watcher.on('stop', common.mustCall(function onStop() {}));
+
+watcher.start();  // starting a started watcher should be a noop