Expose `has` method on Cache.

Reviewed By: davidaurelio

Differential Revision: D2862315

fb-gh-sync-id: 03728a2593b477aef3bbfe01d42382893a05ea50

packager/react-packager/src/DependencyResolver/Cache/__tests__/Cache-test.js

@@ -275,4 +275,32 @@ describe('Cache', () => {
       expect(fs.writeFile).toBeCalled();
     });
   });
+
+  describe('check for cache presence', () => {
+    it('synchronously resolves cache presence', () => {
+      fs.stat.mockImpl((file, callback) =>
+        callback(null, {
+          mtime: {
+            getTime: () => {},
+          },
+        })
+      );
+
+      var cache = new Cache({
+        cacheKey: 'cache',
+      });
+      var loaderCb = jest.genMockFn().mockImpl(() =>
+        Promise.resolve('banana')
+      );
+      var file = '/rootDir/someFile';
+
+      return cache
+        .get(file, 'field', loaderCb)
+        .then(() => {
+          expect(cache.has(file)).toBe(true);
+          expect(cache.has(file, 'field')).toBe(true);
+          expect(cache.has(file, 'foo')).toBe(false);
+        });
+    });
+  });
 });

packager/react-packager/src/DependencyResolver/Cache/index.js

@@ -51,7 +51,7 @@ class Cache {
       throw new Error('Use absolute paths');
     }
 
-    var recordP = this._has(filepath, field)
+    var recordP = this.has(filepath, field)
       ? this._data[filepath].data[field]
       : this._set(filepath, field, loaderCb(filepath));
 
@@ -59,7 +59,7 @@ class Cache {
   }
 
   invalidate(filepath) {
-    if (this._has(filepath)) {
+    if (this.has(filepath)) {
       delete this._data[filepath];
     }
   }
@@ -68,7 +68,7 @@ class Cache {
     return this._persistCache();
   }
 
-  _has(filepath, field) {
+  has(filepath, field) {
     return Object.prototype.hasOwnProperty.call(this._data, filepath) &&
       (!field || Object.prototype.hasOwnProperty.call(this._data[filepath].data, field));
   }