Fix: Match glob handling to vinyl-fs (fixes gulpjs/gulp#2192)

Author: James Quigley

index.js

@@ -4,6 +4,8 @@ var chokidar = require('chokidar');
 var debounce = require('just-debounce');
 var asyncDone = require('async-done');
 var defaults = require('object.defaults/immutable');
+var isNegatedGlob = require('is-negated-glob');
+var anymatch = require('anymatch');
 
 var defaultOpts = {
   delay: 200,
@@ -24,6 +26,10 @@ function hasErrorListener(ee) {
   return listenerCount(ee, 'error') !== 0;
 }
 
+function exists(val) {
+  return val != null;
+}
+
 function watch(glob, options, cb) {
   if (typeof options === 'function') {
     cb = options;
@@ -36,10 +42,51 @@ function watch(glob, options, cb) {
     opt.events = [opt.events];
   }
 
+  if (Array.isArray(glob)) {
+    // We slice so we don't mutate the passed globs array
+    glob = glob.slice();
+  } else {
+    glob = [glob];
+  }
+
   var queued = false;
   var running = false;
 
-  var watcher = chokidar.watch(glob, opt);
+  // These use sparse arrays to keep track of the index in the
+  // original globs array
+  var positives = new Array(glob.length);
+  var negatives = new Array(glob.length);
+
+  // Reverse the glob here so we don't end up with a positive
+  // and negative glob in position 0 after a reverse
+  glob.reverse().forEach(sortGlobs);
+
+  function sortGlobs(globString, index) {
+    var result = isNegatedGlob(globString);
+    if (result.negated) {
+      negatives[index] = result.pattern;
+    } else {
+      positives[index] = result.pattern;
+    }
+  }
+
+  function shouldBeIgnored(path) {
+    var positiveMatch = anymatch(positives, path, true);
+    var negativeMatch = anymatch(negatives, path, true);
+    // If negativeMatch is -1, that means it was never negated
+    if (negativeMatch === -1) {
+      return false;
+    }
+
+    // If the negative is "less than" the positive, that means
+    // it came later in the glob array before we reversed them
+    return negativeMatch < positiveMatch;
+  }
+
+  var toWatch = positives.filter(exists);
+
+  opt.ignored = shouldBeIgnored;
+  var watcher = chokidar.watch(toWatch, opt);
 
   function runComplete(err) {
     running = false;

package.json

@@ -21,8 +21,10 @@
     "coveralls": "npm run cover && istanbul-coveralls"
   },
   "dependencies": {
+    "anymatch": "^2.0.0",
     "async-done": "^1.2.0",
     "chokidar": "^2.0.0",
+    "is-negated-glob": "^1.0.0",
     "just-debounce": "^1.0.0",
     "object.defaults": "^1.1.0"
   },

test/index.js

@@ -22,6 +22,8 @@ describe('glob-watcher', function() {
   var outFile2 = path.join(outDir, 'added.js');
   var globPattern = '**/*.js';
   var outGlob = normalizePath(path.join(outDir, globPattern));
+  var singleAdd = normalizePath(path.join(outDir, 'changed.js'));
+  var ignoreGlob = '!' + singleAdd;
 
   function changeFile() {
     fs.writeFileSync(outFile1, 'hello changed');
@@ -279,4 +281,42 @@ describe('glob-watcher', function() {
       setTimeout(done, 500);
     });
   });
+
+  it('can ignore a glob after it has been added', function(done) {
+    watcher = watch([outGlob, ignoreGlob]);
+
+    watcher.once('change', function(filepath) {
+      // It should never reach here
+      expect(filepath).toNotExist();
+      done();
+    });
+
+    // We default `ignoreInitial` to true, so always wait for `on('ready')`
+    watcher.on('ready', changeFile);
+
+    setTimeout(done, 1500);
+  });
+
+  it('can re-add a glob after it has been negated', function(done) {
+    watcher = watch([outGlob, ignoreGlob, singleAdd]);
+
+    watcher.once('change', function(filepath) {
+      expect(filepath).toEqual(singleAdd);
+      done();
+    });
+
+    // We default `ignoreInitial` to true, so always wait for `on('ready')`
+    watcher.on('ready', changeFile);
+  });
+
+  it('does not mutate the globs array', function(done) {
+    var globs = [outGlob, ignoreGlob, singleAdd];
+    watcher = watch(globs);
+
+    expect(globs[0]).toEqual(outGlob);
+    expect(globs[1]).toEqual(ignoreGlob);
+    expect(globs[2]).toEqual(singleAdd);
+
+    done();
+  });
 });