Auto-resolve promises in data on request

Author: ericingram

lib/client.js

@@ -143,6 +143,14 @@ Client.prototype.request = function(method, url, data, callback) {
         this.connect();
     }
 
+    // Resolve data as promised
+    var promises = this.promisifyData(data);
+    if (promises.length) {
+        return Promise.all(promises).bind(this).then(function() {
+            this.request(method, url, data, callback);
+        });
+    }
+
     // Prepare url and data for request
     url = url && url.toString ? url.toString() : '';
     data = {$data: data};
@@ -186,6 +194,47 @@ Client.prototype.request = function(method, url, data, callback) {
     });
 };
 
+/**
+ * Resolve and return promises array from data
+ * Only resolve top level object keys
+ *
+ * @param  object data
+ * @return array
+ */
+Client.prototype.promisifyData = function(data) {
+
+    if (!data) {
+      return [];
+    }
+
+    function thenResolvePromisedValue(data, key) {
+        data[key].then(function(val) {
+            data[key] = val;
+        });
+    }
+
+    var promises = [];
+    if (typeof data === 'object') {
+        var keys = Object.keys(data);
+        for (var i = 0; i < keys.length; i++) {
+            var key = keys[i];
+            if (data[key] && data[key].then) {
+                promises.push(data[key]);
+                thenResolvePromisedValue(data, key);
+            }
+        }
+    } else if (data instanceof Array) {
+        for (var i = 0; i < data.length; i++) {
+            if (data[i] && data[i].then) {
+                promises.push(data[i]);
+                thenResolvePromisedValue(data, i);
+            }
+        }
+    }
+
+    return promises;
+};
+
 /**
  * Client response handler
  *

lib/schema.js

@@ -1244,6 +1244,9 @@ Record.prototype.__initLinks = function(links) {
             res.__client.get(url, null, callback);
             return this;
         };
+        if (res[key] === undefined) {
+          return;
+        }
         // record.link.each(...)
         res[key].each = function(callback, then) {
             if (typeof callback !== 'function') return;

test/client.spec.js

@@ -325,6 +325,36 @@ describe('Client', function() {
         assert.strictEqual(calledBack, true);
       });
     });
+
+    it('resolves promised data (object)', function() {
+      var data = {
+        test1: Promise.resolve('hello'),
+        test2: Promise.resolve('world'),
+        test3: 'static'
+      };
+
+      return client.request('get', 'url', data).then(function() {
+        assert.deepEqual(serverRequestStub.args[0][2].$data, {
+          test1: 'hello',
+          test2: 'world',
+          test3: 'static'
+        });
+      });
+    });
+
+    it('resolves promised data (array)', function() {
+      var data = [
+        Promise.resolve('hello'),
+        Promise.resolve('world'),
+        'static'
+      ];
+
+      return client.request('get', 'url', data).then(function() {
+        assert.deepEqual(serverRequestStub.args[0][2].$data, [
+          'hello', 'world', 'static'
+        ]);
+      });
+    });
   });
 
   describe('#respond', function() {
@@ -544,4 +574,4 @@ describe('Client', function() {
       assert(resource instanceof Schema.Record);
     });
   });
-});
+});