yuanchuan · ianshade · May 5, 2022 · May 6, 2022 · May 9, 2022 · May 10, 2022
diff --git a/lib/is.js b/lib/is.js
@@ -1,4 +1,4 @@
-var fs = require('fs');
+var fs = require('fs-extra');
 var path = require('path');
 var os = require('os');
 
@@ -7,16 +7,13 @@ function matchObject(item, str) {
     === '[object ' + str + ']';
 }
 
-function checkStat(name, fn) {
-  try {
-    return fn(name);
-  } catch (err) {
-    if (/^(ENOENT|EPERM|EACCES)$/.test(err.code)) {
-      if (err.code !== 'ENOENT') {
-        console.warn('Warning: Cannot access %s', name);
-      }
-      return false;
+function checkStat(err) {
+  if (/^(ENOENT|EPERM|EACCES)$/.test(err.code)) {
+    if (err.code !== 'ENOENT') {
+      console.warn('Warning: Cannot access %s', name);
     }
+    return false;
+  } else {
     throw err;
   }
 }
@@ -49,26 +46,28 @@ var is = {
   number: function(item) {
     return matchObject(item, 'Number');
   },
-  exists: function(name) {
-    return fs.existsSync(name);
+  exists: async function(name) {
+    return fs.access(name, fs.constants.F_OK)
+      .then(() => true)
+      .catch(() => false)
   },
-  file: function(name) {
-    return checkStat(name, function(n) {
-      return fs.statSync(n).isFile()
-    });
+  file: async function(name) {
+    return fs.stat(name)
+      .then((stats) => stats.isFile())
+      .catch(checkStat)
   },
   samePath: function(a, b) {
     return path.resolve(a) === path.resolve(b);
   },
-  directory: function(name) {
-    return checkStat(name, function(n) {
-      return fs.statSync(n).isDirectory()
-    });
+  directory: async function(name) {
+    return fs.stat(name)
+      .then((stats) => stats.isDirectory())
+      .catch(checkStat)
   },
   symbolicLink: function(name) {
-    return checkStat(name, function(n) {
-      return fs.lstatSync(n).isSymbolicLink();
-    });
+    return fs.stat(name)
+      .then((stats) => stats.isSymbolicLink())
+      .catch(checkStat)
   },
   windows: function() {
     return os.platform() === 'win32';

diff --git a/lib/watch.d.ts b/lib/watch.d.ts
@@ -21,7 +21,7 @@ declare function watch(pathName: PathName, options: Options) : Watcher;
 declare function watch(pathName: PathName, callback: Callback): Watcher;
 declare function watch(pathName: PathName, options: Options, callback: Callback): Watcher;
 
-type EventType = 'update' | 'remove';
+export type EventType = 'update' | 'remove';
 type Callback = (eventType: EventType, filePath: string) => any;
 type PathName = string | Array<string>;
 type FilterReturn = boolean | symbol;
@@ -60,7 +60,7 @@ type Options = {
   delay ?: number;
 };
 
-declare interface Watcher extends FSWatcher {
+export interface Watcher extends FSWatcher {
   /**
    * Returns `true` if the watcher has been closed.
    */

diff --git a/lib/watch.js b/lib/watch.js
@@ -1,4 +1,4 @@
-var fs = require('fs');
+var fs = require('fs-extra');
 var path = require('path');
 var util = require('util');
 var events = require('events');
@@ -52,15 +52,17 @@ function guard(fn) {
   }
 }
 
-function composeMessage(names) {
-  return names.map(function(n) {
-    return is.exists(n)
+async function composeMessage(names) {
+  const ps = names.map((n) => is.exists(n))
+  const exists = await Promise.all(ps)
+  return names.map((n, index) => {
+    return exists[index]
       ? [EVENT_UPDATE, n]
       : [EVENT_REMOVE, n];
-  });
+  })
 }
 
-function getMessages(cache) {
+async function getMessages(cache) {
   var filtered = unique(cache);
 
   // Saving file from an editor? If so, assuming the
@@ -76,9 +78,13 @@ function getMessages(cache) {
       return c.replace(reg, '');
     }));
     if (dup) {
-      filtered = filtered.filter(function(m) {
+      var existing = filtered.map(function(m) {
         return is.exists(m);
       });
+      await Promise.all(existing);
+      filtered = filtered.filter((v, index) => {
+        return existing[index]
+      })
     }
   }
 
@@ -92,16 +98,18 @@ function debounce(info, fn) {
   if (!is.number(delay)) {
     delay = 200;
   }
-  function handle() {
-    getMessages(cache).forEach(function(msg) {
+  async function handle() {
+    const cacheClone = [...cache]
+    cache = [];
+    timer = null;
+    const messages = await getMessages(cacheClone)
+    messages.forEach(function(msg) {
       msg[1] = Buffer.from(msg[1]);
       if (encoding !== 'buffer') {
         msg[1] = msg[1].toString(encoding);
       }
       fn.apply(null, msg);
     });
-    timer = null;
-    cache = [];
   }
   return function(rawEvt, name) {
     cache.push(name);
@@ -126,27 +134,24 @@ function createDupsFilter() {
   }
 }
 
-function getSubDirectories(dir, fn, done = function() {}) {
-  if (is.directory(dir)) {
-    fs.readdir(dir, function(err, all) {
-      if (err) {
-        // don't throw permission errors.
-        if (/^(EPERM|EACCES)$/.test(err.code)) {
-          console.warn('Warning: Cannot access %s.', dir);
-        } else {
-          throw err;
-        }
-      }
-      else {
-        all.forEach(function(f) {
-          var sdir = path.join(dir, f);
-          if (is.directory(sdir)) fn(sdir);
-        });
-        done();
+async function getSubDirectories(dir, fn) {
+  if (!(await is.directory(dir))) return;
+  try {
+    const all = await fs.readdir(dir);
+    const subDirs = all.map(async function(f) {
+      var sdir = path.join(dir, f);
+      if (await (is.directory(sdir))) {
+        fn(sdir);
       }
     });
-  } else {
-    done();
+    return Promise.allSettled(subDirs);
+  } catch(err) {
+    // don't throw permission errors.
+    if (/^(EPERM|EACCES)$/.test(err.code)) {
+      console.warn('Warning: Cannot access %s.', dir);
+    } else {
+      throw err;
+    }
   }
 }
 
@@ -218,7 +223,8 @@ Watcher.prototype.close = function(fullPath) {
     }
     getSubDirectories(fullPath, function(fpath) {
       self.close(fpath);
-    });
+    })
+      .catch((err) => self.emit('error', err))
   }
   else {
     Object.keys(self.watchers).forEach(function(fpath) {
@@ -291,20 +297,23 @@ Watcher.prototype.add = function(watcher, info) {
       hasNativeRecursive(function(has) {
         if (!has) {
           var fullPath = path.resolve(name);
-          // remove watcher on removal
-          if (!is.exists(name)) {
-            self.close(fullPath);
-          }
-          // watch new created directory
-          else {
-            var shouldWatch = is.directory(name)
-              && !self.watchers[fullPath]
-              && shouldNotSkip(name, info.options.filter);
-
-            if (shouldWatch) {
-              self.watchDirectory(name, info.options);
-            }
-          }
+          is.exists(name)
+            .then(async exists => {
+              if (!exists) {
+                // remove watcher on removal
+                self.close(fullPath);
+              } else {
+                // watch new created directory
+                var shouldWatch = !self.watchers[fullPath]
+                  && await is.directory(name)
+                  && shouldNotSkip(name, info.options.filter);
+
+                if (shouldWatch) {
+                  self.watchDirectory(name, info.options);
+                }
+              }
+            })
+            .catch((err) => self.emit('error', err))
         }
       });
     }
@@ -413,7 +422,9 @@ Watcher.prototype.watchDirectory = function(dir, options, fn, counter = nullCoun
         if (shouldNotSkip(d, options.filter)) {
           self.watchDirectory(d, options, null, counter);
         }
-      }, counter());
+      })
+        .then(() => counter())
+        .catch((err) => self.emit('error', err))
     }
 
     done();
@@ -470,12 +481,16 @@ function watch(fpath, options, fn) {
     fpath = fpath.toString();
   }
 
-  if (!is.array(fpath) && !is.exists(fpath)) {
-    process.nextTick(function() {
-      watcher.emit('error',
-        new Error(fpath + ' does not exist.')
-      );
-    });
+  if (!is.array(fpath)) {
+    is.exists(fpath).then((result) => {
+      if (!result) {
+        process.nextTick(function() {
+          watcher.emit('error',
+            new Error(fpath + ' does not exist.')
+          );
+        });
+      }
+    })
   }
 
   if (is.string(options)) {
@@ -513,17 +528,22 @@ function watch(fpath, options, fn) {
     }));
   }
 
-  if (is.file(fpath)) {
-    watcher.watchFile(fpath, options, fn);
-    emitReady(watcher);
-  }
-
-  else if (is.directory(fpath)) {
-    var counter = semaphore(function () {
-      emitReady(watcher);
-    });
-    watcher.watchDirectory(fpath, options, fn, counter);
-  }
+  is.file(fpath)
+    .then((isFile) => {
+      if (isFile) {
+        watcher.watchFile(fpath, options, fn);
+        emitReady(watcher);
+      } else {
+        return is.directory(fpath).then((isDirectory) => {
+          if (!isDirectory) return
+          var counter = semaphore(function () {
+            emitReady(watcher);
+          });
+          watcher.watchDirectory(fpath, options, fn, counter);
+        })
+      }
+    })
+    .catch((err) => self.emit('error', err))
 
   return watcher.expose();
 }

diff --git a/package.json b/package.json
@@ -29,8 +29,10 @@
   "engines": {
     "node": ">=6"
   },
+  "dependencies": {
+    "fs-extra": "^10.1.0"
+  },
   "devDependencies": {
-    "fs-extra": "^7.0.1",
     "mocha": "^5.2.0"
   }
 }