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>

1 files changed, 63 insertions, 0 deletions

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