Merge pull request #168 from nordfjord/remove-promise-swallowing

Break things (followup from #166)

Author: paldepind

README.md

@@ -46,6 +46,7 @@ __Other features__
 
 * Supports the transducer protocol. You can for instance transduce streams with
   [Ramda](http://ramdajs.com/) and [transducers.js](https://github.com/jlongster/transducers.js).
+* Conforms to the fantasy land [monad](https://github.com/fantasyland/fantasy-land#monad) specification
 * [Atomic updates](#atomic-updates).
 
 ## Examples
@@ -647,7 +648,7 @@ var evenNumbers = numbers
   .pipe(filter(isEven));
 ```
 
-### stream.map(f) __Deprecated__
+### stream.map(f)
 
 Returns a new stream identical to the original except every
 value will be passed through `f`.
@@ -666,7 +667,7 @@ var numbers = flyd.stream(0);
 var squaredNumbers = numbers.map(function(n) { return n*n; });
 ```
 
-### stream1.ap(stream2) __Deprecated__
+### stream1.ap(stream2)
 
 `stream1` must be a stream of functions.
 

examples/drag-and-drop/script.js

@@ -1,5 +1,4 @@
 var flyd = require('flyd');
-var flatMap = require('flyd/module/flatmap');
 var takeUntil = require('flyd/module/takeuntil');
 
 document.addEventListener('DOMContentLoaded', function() {
@@ -13,7 +12,7 @@ document.addEventListener('DOMContentLoaded', function() {
   document.addEventListener('mousemove', mousemove);
   document.addEventListener('mouseup', mouseup);
 
-  var mousedrag = flatMap(function(md) {
+  var mousedrag = flyd.chain(function(md) {
     var startX = md.offsetX, startY = md.offsetY;
 
     return takeUntil(flyd.map(function(mm) {

index.d.ts

@@ -128,16 +128,6 @@ declare module 'flyd/module/filter' {
   export = _Filter;
 }
 
-declare module 'flyd/module/flatmap' {
-  type projection<T, V> = (val: T) => flyd.Stream<V>;
-  interface flatMap {
-    <T, V>(project: projection<T, V>, source: flyd.Stream<T>): flyd.Stream<V>;
-    <T, V>(project: projection<T, V>): (source: flyd.Stream<T>) => flyd.Stream<V>;
-  }
-  const _flatMap: flatMap;
-  export = _flatMap;
-}
-
 declare module 'flyd/module/forwardto' {
   interface ForwardTo {
     <T, V>(stream: flyd.Stream<V>, project: (value: V) => T): flyd.Stream<T>;

lib/index.js

@@ -438,7 +438,6 @@ flyd.fromPromise = function fromPromise(p) {
   return s;
 }
 
-/* istanbul ignore next */
 flyd.flattenPromise = function flattenPromise(s) {
   return combine(function(s, self) {
     s().then(self);
@@ -676,12 +675,6 @@ function flushUpdate() {
  * @param {*} value
  */
 function updateStreamValue(s, n) {
-  /* istanbul ignore if  */
-  if (n !== undefined && n !== null && isFunction(n.then)) {
-    console.warn('flyd: Promise swallowing has been deprecated, please see https://github.com/paldepind/flyd#promises for more info');
-    n.then(s);
-    return;
-  }
   s.val = n;
   s.hasVal = true;
   if (inStream === undefined) {

module/flatmap/README.md

@@ -369,26 +369,86 @@ describe('stream', function() {
     });
   });
 
-  describe('promise swallowing', function() {
-    it('pushes result of promise down the stream', function(done) {
-      var s = flyd.fromPromise(Promise.resolve(12));
-      combine(function(s) {
-        assert.equal(s(), 12);
-        done();
-      }, [s]);
+  describe('Promises', function() {
+    describe('fromPromise', function() {
+      it('pushes result of promise down the stream', function(done) {
+        var s = flyd.fromPromise(Promise.resolve(12));
+        combine(function(s) {
+          assert.equal(s(), 12);
+          done();
+        }, [s]);
+      });
+      it('recursively unpacks promise', function(done) {
+        var s = flyd.fromPromise(new Promise(function(res) {
+          setTimeout(function() {
+            res(new Promise(function(res) {
+              setTimeout(res.bind(null, 12));
+            }));
+          }, 20);
+        }));
+        combine(function(s) {
+          assert.equal(s(), 12);
+          done();
+        }, [s]);
+      });
+
+      it('does not process out of order promises', function(done) {
+        var promises = [];
+        var delay = function(ms, val) {
+          var p = new Promise(function(res) {
+            setTimeout(function() {
+              res(val);
+            }, ms)
+          });
+          promises.push(p);
+          return p;
+        };
+
+        var s = stream();
+        var res = s.chain(function(val) {
+          return flyd.fromPromise(delay(val, val));
+        })
+          .pipe(flyd.scan(function(acc, v) {
+            return acc + v;
+          }, 0));
+        s(100)(50)(70)(200);
+
+        Promise.all(promises).then(function() {
+          assert.equal(res(), 200);
+          done();
+        });
+
+      });
     });
-    it('recursively unpacks promise', function(done) {
-      var s = flyd.fromPromise(new Promise(function(res) {
-        setTimeout(function() {
-          res(new Promise(function(res) {
-            setTimeout(res.bind(null, 12));
-          }));
-        }, 20);
-      }));
-      combine(function(s) {
-        assert.equal(s(), 12);
-        done();
-      }, [s]);
+    describe('flattenPromise', function() {
+      it('processes out of order promises', function(done) {
+        var promises = [];
+        var delay = function(ms, val) {
+          var p = new Promise(function(res) {
+            setTimeout(function() {
+              res(val);
+            }, ms)
+          });
+          promises.push(p);
+          return p;
+        };
+
+        var s = stream();
+        var res = s.map(function(val) {
+          return delay(val, val);
+        })
+          .pipe(flyd.flattenPromise)
+          .pipe(flyd.scan(function(acc, v) {
+            return acc + v;
+          }, 0));
+        s(100)(50)(70)(200);
+
+        Promise.all(promises).then(function() {
+          assert.equal(res(), 420);
+          done();
+        });
+
+      });
     });
   });