Add a .getSync() function

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>
electron-userland · Apr 13, 2021 · ea3a364 · ea3a364
1 parent 3f23e43
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Showing 5 changed files with 235 additions and 5 deletions.
diff --git a/README.md b/README.md
@@ -8,7 +8,7 @@ electron-json-storage
 [![Build Status](https://travis-ci.org/electron-userland/electron-json-storage.svg?branch=master)](https://travis-ci.org/electron-userland/electron-json-storage)
 [![Build status](https://ci.appveyor.com/api/projects/status/ulwk1nnh7l8209xg/branch/master?svg=true)](https://ci.appveyor.com/project/electron-userland/electron-json-storage/branch/master)
 
-[Electron](http://electron.atom.io) lacks an easy way to persist and read user settings for your application. `electron-json-storage` implements an API somehow similar to [localStorage](https://developer.mozilla.org/en/docs/Web/API/Window/localStorage) to write and read JSON objects to/from the operating system application data directory, as defined by `app.getPath('userData')`.
+[Electron](http://electron.atom.io) lacks an easy way to persist and read user settings for your application. `electron-json-storage` implements an API somewhat similar to [localStorage](https://developer.mozilla.org/en/docs/Web/API/Window/localStorage) to write and read JSON objects to/from the operating system application data directory, as defined by `app.getPath('userData')`.
 
 Related modules:
 
@@ -35,7 +35,7 @@ When loaded in renderer processes, this module will try to make use of
 
 Electron 10 now [defaults `enableRemoteModule` to
 false](https://www.electronjs.org/docs/breaking-changes#default-changed-enableremotemodule-defaults-to-false),
-which means that `electron-json-storage` will not be able to calculate a data path by default.
+which means that `electron-json-storage` will be able to calculate a data path by default.
 
 The solution is to manually call `storage.setDataPath()` before reading or
 writing any values or setting `enableRemoteModule` to `true`.
@@ -49,6 +49,7 @@ Documentation
     * [.setDataPath(directory)](#module_storage.setDataPath)
     * [.getDataPath()](#module_storage.getDataPath) ⇒ <code>String</code>
     * [.get(key, [options], callback)](#module_storage.get)
+    * [.getSync(key, [options])](#module_storage.getSync)
     * [.getMany(keys, [options], callback)](#module_storage.getMany)
     * [.getAll([options], callback)](#module_storage.getAll)
     * [.set(key, json, [options], callback)](#module_storage.set)
@@ -142,6 +143,28 @@ storage.get('foobar', function(error, data) {
   console.log(data);
 });
 ```
+<a name="module_storage.getSync"></a>
+
+### storage.getSync(key, [options])
+See `.get()`.
+
+**Kind**: static method of [<code>storage</code>](#module_storage)  
+**Summary**: Read user data (sync)  
+**Access**: public  
+
+| Param | Type | Description |
+| --- | --- | --- |
+| key | <code>String</code> | key |
+| [options] | <code>Object</code> | options |
+| [options.dataPath] | <code>String</code> | data path |
+
+**Example**  
+```js
+const storage = require('electron-json-storage');
+
+var data = storage.getSync('foobar');
+console.log(data);
+```
 <a name="module_storage.getMany"></a>
 
 ### storage.getMany(keys, [options], callback)

diff --git a/doc/README.hbs b/doc/README.hbs
@@ -8,7 +8,7 @@ electron-json-storage
 [![Build Status](https://travis-ci.org/electron-userland/electron-json-storage.svg?branch=master)](https://travis-ci.org/electron-userland/electron-json-storage)
 [![Build status](https://ci.appveyor.com/api/projects/status/ulwk1nnh7l8209xg/branch/master?svg=true)](https://ci.appveyor.com/project/electron-userland/electron-json-storage/branch/master)
 
-[Electron](http://electron.atom.io) lacks an easy way to persist and read user settings for your application. `electron-json-storage` implements an API somehow similar to [localStorage](https://developer.mozilla.org/en/docs/Web/API/Window/localStorage) to write and read JSON objects to/from the operating system application data directory, as defined by `app.getPath('userData')`.
+[Electron](http://electron.atom.io) lacks an easy way to persist and read user settings for your application. `electron-json-storage` implements an API somewhat similar to [localStorage](https://developer.mozilla.org/en/docs/Web/API/Window/localStorage) to write and read JSON objects to/from the operating system application data directory, as defined by `app.getPath('userData')`.
 
 Related modules:
 

diff --git a/lib/lock.js b/lib/lock.js
@@ -58,7 +58,7 @@ exports.lock = function(file, callback, times) {
   lockFile.lock(file, lockOptions, function(error) {
     if (error && error.code === 'EPERM' && times < 10) {
       setTimeout(function() {
-        exports.unlock(file, callback, times + 1);
+        exports.lock(file, callback, times + 1);
       }, 1000);
       return;
     }
@@ -68,7 +68,31 @@ exports.lock = function(file, callback, times) {
 };
 
 /**
- * @summary Unlock a lock file
+ * @summary Create a lock file (sync)
+ * @function
+ * @public
+ *
+ * @param {String} file - lock file
+ *
+ * @example
+ * lock.lockSync('foo.lock');
+ */
+exports.lockSync = function(file, times) {
+  times = times || 0;
+
+  try {
+    lockFile.lockSync(file, lockOptions);
+  } catch (error) {
+    if (error && error.code === 'EPERM' && times < 10) {
+      return exports.lockSync(file, times + 1);
+    }
+
+    throw error;
+  }
+};
+
+/**
+ * @summary Unlock a locked file
  * @function
  * @public
  *
@@ -96,3 +120,27 @@ exports.unlock = function(file, callback, times) {
     return callback(error);
   });
 };
+
+/**
+ * @summary Unlock a locked file (sync)
+ * @function
+ * @public
+ *
+ * @param {String} file - lock file
+ *
+ * @example
+ * lock.unlockSync('foo.lock');
+ */
+exports.unlockSync = function(file, times) {
+  times = times || 0;
+
+  try {
+    lockFile.unlockSync(file);
+  } catch (error) {
+    if (error && error.code === 'EPERM' && times < 10) {
+      return exports.unlockSync(file, times + 1);
+    }
+
+    throw error;
+  }
+};
diff --git a/lib/storage.js b/lib/storage.js
@@ -61,6 +61,23 @@ const readFile = function(fileName, callback, times) {
   });
 };
 
+const readFileSync = function(fileName, times) {
+  times = times || 0;
+  try {
+    return fs.readFileSync(fileName);
+  } catch (error) {
+    if (error.code === 'ENOENT') {
+      return JSON.stringify({});
+    }
+
+    if (error.code === 'EPERM' && times < 10) {
+      return readFileSync(fileName, times + 1);
+    }
+
+    throw error;
+  }
+};
+
 /**
  * @summary Get the default data path
  * @function
@@ -193,6 +210,52 @@ exports.get = function(key, options, callback) {
   });
 };
 
+/**
+ * @summary Read user data (sync)
+ * @function
+ * @public
+ *
+ * @description
+ * See `.get()`.
+ *
+ * @param {String} key - key
+ * @param {Object} [options] - options
+ * @param {String} [options.dataPath] - data path
+ *
+ * @example
+ * const storage = require('electron-json-storage');
+ *
+ * var data = storage.getSync('foobar');
+ * console.log(data);
+ */
+exports.getSync = function(key, options) {
+  options = options || {};
+  var fileName = utils.getFileName(key, {
+    dataPath: options.dataPath
+  });
+
+  mkdirp.sync(path.dirname(fileName));
+
+  try {
+    lock.lockSync(utils.getLockFileName(fileName));
+  } catch (error) {
+    if (error && error.code === 'EEXIST') {
+      return exports.getSync(key, options);
+    }
+
+    throw error;
+  }
+
+  var object = readFileSync(fileName);
+  lock.unlockSync(utils.getLockFileName(fileName));
+
+  try {
+    return JSON.parse(object);
+  } catch (error) {
+    throw new Error('Invalid data: ' + object);
+  }
+};
+
 /**
  * @summary Read many user data keys
  * @function

diff --git a/tests/storage.spec.js b/tests/storage.spec.js
@@ -160,6 +160,13 @@ describe('Electron JSON Storage', function() {
       });
     });
 
+    it('should yield an error if no key (sync)', function(done) {
+      chai.expect(() => {
+        storage.getSync(null);
+      }).to.throw('Missing key');
+      done();
+    });
+
     it('should yield an error if key is not a string', function(done) {
       storage.get(123, function(error, data) {
         chai.expect(error).to.be.an.instanceof(Error);
@@ -169,6 +176,13 @@ describe('Electron JSON Storage', function() {
       });
     });
 
+    it('should yield an error if key is not a string (sync)', function(done) {
+      chai.expect(() => {
+        storage.getSync(123);
+      }).to.throw('Invalid key');
+      done();
+    });
+
     it('should yield an error if key is a blank string', function(done) {
       storage.get('    ', function(error, data) {
         chai.expect(error).to.be.an.instanceof(Error);
@@ -178,6 +192,13 @@ describe('Electron JSON Storage', function() {
       });
     });
 
+    it('should yield an error if key is a blank string (sync)', function(done) {
+      chai.expect(() => {
+        storage.getSync('     ');
+      }).to.throw('Invalid key');
+      done();
+    });
+
     describe('given the user data path does not exist', function() {
 
       beforeEach(function(done) {
@@ -196,6 +217,12 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should return an empty object for any key (sync)', function(done) {
+        var data = storage.getSync('foobarbaz');
+        chai.expect(data).to.deep.equal({});
+        done();
+      });
+
     });
 
     describe('given the same key stored in multiple data paths', function(done) {
@@ -233,6 +260,15 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should initially return the key in the default location (sync)', function(done) {
+        var data = storage.getSync('foo');
+        chai.expect(data).to.deep.equal({
+          location: 'default'
+        });
+
+        done();
+      });
+
       it('should return the new value given the right data path', function(done) {
         storage.setDataPath(this.newDataPath);
         storage.get('foo', function(error, data) {
@@ -245,6 +281,16 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should return the new value given the right data path (sync)', function(done) {
+        storage.setDataPath(this.newDataPath);
+        var data = storage.getSync('foo');
+        chai.expect(data).to.deep.equal({
+          location: 'new'
+        });
+
+        done();
+      });
+
       it('should return nothing given the wrong data path', function(done) {
         if (os.platform() === 'win32') {
           storage.setDataPath('C:\\tmp\\electron-json-storage');
@@ -263,6 +309,25 @@ describe('Electron JSON Storage', function() {
           done();
         });
       });
+
+      it('should return nothing given the wrong data path (sync)', function(done) {
+        if (os.platform() === 'win32') {
+          storage.setDataPath('C:\\tmp\\electron-json-storage');
+        } else {
+          storage.setDataPath('/tmp/electron-json-storage');
+        }
+
+        async.waterfall([
+          storage.clear,
+          function(callback) {
+            callback(null, storage.getSync('foo'));
+          }
+        ], function(error, data) {
+          chai.expect(error).to.not.exist;
+          chai.expect(data).to.deep.equal({});
+          done();
+        });
+      });
     });
 
     describe('given stored keys with a colon', function() {
@@ -301,6 +366,12 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should yield the data (sync)', function(done) {
+        var data = storage.getSync('foo');
+        chai.expect(data).to.deep.equal({ data: 'hello world' });
+        done();
+      });
+
       it('should yield the data if explicitly passing the extension', function(done) {
         storage.get('foo.json', function(error, data) {
           chai.expect(error).to.not.exist;
@@ -309,6 +380,12 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should yield the data if explicitly passing the extension (sync)', function(done) {
+        var data = storage.getSync('foo.json');
+        chai.expect(data).to.deep.equal({ data: 'hello world' });
+        done();
+      });
+
       it('should yield an empty object given an incorrect key', function(done) {
         storage.get('foobarbaz', function(error, data) {
           chai.expect(error).to.not.exist;
@@ -317,6 +394,12 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should yield an empty object given an incorrect key (sync)', function(done) {
+        var data = storage.getSync('foobarbaz');
+        chai.expect(data).to.deep.equal({});
+        done();
+      });
+
     });
 
     describe('given invalid stored JSON', function() {
@@ -340,6 +423,13 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should yield an error (sync)', function(done) {
+        chai.expect(() => {
+          return storage.getSync('foo');
+        }).to.throw('Invalid data: Foo{bar}123');
+        done();
+      });
+
     });
 
     describe('given a non-existent user data path', function() {
@@ -365,6 +455,12 @@ describe('Electron JSON Storage', function() {
         });
       });
 
+      it('should return an empty object for any key (sync)', function(done) {
+        var result = storage.getSync('foo');
+        chai.expect(result).to.deep.equal({});
+        done();
+      });
+
     });
 
   });