Bugfix: thunk function called two times

PR #273

* Separate test blocks with newlines
* Add a 🔴 failing test that highlights the bug, and some other more detailed tests on thunk renderings
* Fix the bug ✅
* Correctly gitignore files in base directory
The existing configuration was ignoring the same filenames in subdirectories, for example `test/thunk.js`
* Remove newlines between test blocks
* Make tests titles more explicative

.gitignore

@@ -30,34 +30,34 @@ node_modules
 *.swp
 
 # Generated JavaScript
-test/browserified.js
-browserified.js
-h.d.ts
-h.js
-h.js.map
-hooks.d.ts
-hooks.js
-hooks.js.map
-htmldomapi.d.ts
-htmldomapi.js
-htmldomapi.js.map
-is.d.ts
-is.js
-is.js.map
-snabbdom.bundle.d.ts
-snabbdom.bundle.js
-snabbdom.bundle.js.map
-snabbdom.d.ts
-snabbdom.js
-snabbdom.js.map
-thunk.d.ts
-thunk.js
-thunk.js.map
-tovnode.d.ts
-tovnode.js
-tovnode.js.map
-vnode.d.ts
-vnode.js
-vnode.js.map
+/test/browserified.js
+/browserified.js
+/h.d.ts
+/h.js
+/h.js.map
+/hooks.d.ts
+/hooks.js
+/hooks.js.map
+/htmldomapi.d.ts
+/htmldomapi.js
+/htmldomapi.js.map
+/is.d.ts
+/is.js
+/is.js.map
+/snabbdom.bundle.d.ts
+/snabbdom.bundle.js
+/snabbdom.bundle.js.map
+/snabbdom.d.ts
+/snabbdom.js
+/snabbdom.js.map
+/thunk.d.ts
+/thunk.js
+/thunk.js.map
+/tovnode.d.ts
+/tovnode.js
+/tovnode.js.map
+/vnode.d.ts
+/vnode.js
+/vnode.js.map
 /modules
 /helpers

src/thunk.ts

@@ -36,6 +36,7 @@ function prepatch(oldVnode: VNode, thunk: VNode): void {
   const oldArgs = old.args, args = cur.args;
   if (old.fn !== cur.fn || (oldArgs as any).length !== (args as any).length) {
     copyToThunk((cur.fn as any).apply(undefined, args), thunk);
+    return;
   }
   for (i = 0; i < (args as any).length; ++i) {
     if ((oldArgs as any)[i] !== (args as any)[i]) {

test/thunk.js

@@ -20,7 +20,7 @@ describe('thunk', function() {
     assert.deepEqual(vnode.data.key, 'num');
     assert.deepEqual(vnode.data.args, [22]);
   });
-  it('only calls render function on data change', function() {
+  it('calls render function once on data change', function() {
     var called = 0;
     function numberInSpan(n) {
       called++;
@@ -30,14 +30,66 @@ describe('thunk', function() {
       thunk('span', 'num', numberInSpan, [1])
     ]);
     var vnode2 = h('div', [
+      thunk('span', 'num', numberInSpan, [2])
+    ]);
+    patch(vnode0, vnode1);
+    assert.equal(called, 1);
+    patch(vnode1, vnode2);
+    assert.equal(called, 2);
+  });
+  it('does not call render function on data unchanged', function() {
+    var called = 0;
+    function numberInSpan(n) {
+      called++;
+      return h('span', {key: 'num'}, 'Number is ' + n);
+    }
+    var vnode1 = h('div', [
       thunk('span', 'num', numberInSpan, [1])
     ]);
-    var vnode3 = h('div', [
-      thunk('span', 'num', numberInSpan, [2])
+    var vnode2 = h('div', [
+      thunk('span', 'num', numberInSpan, [1])
+    ]);
+    patch(vnode0, vnode1);
+    assert.equal(called, 1);
+    patch(vnode1, vnode2);
+    assert.equal(called, 1);
+  });
+  it('calls render function once on data-length change', function() {
+    var called = 0;
+    function numberInSpan(n) {
+      called++;
+      return h('span', {key: 'num'}, 'Number is ' + n);
+    }
+    var vnode1 = h('div', [
+      thunk('span', 'num', numberInSpan, [1])
+    ]);
+    var vnode2 = h('div', [
+      thunk('span', 'num', numberInSpan, [1, 2])
     ]);
     patch(vnode0, vnode1);
+    assert.equal(called, 1);
+    patch(vnode1, vnode2);
+    assert.equal(called, 2);
+  });
+  it('calls render function once on function change', function() {
+    var called = 0;
+    function numberInSpan(n) {
+      called++;
+      return h('span', {key: 'num'}, 'Number is ' + n);
+    }
+    function numberInSpan2(n) {
+      called++;
+      return h('span', {key: 'num'}, 'Number really is ' + n);
+    }
+    var vnode1 = h('div', [
+      thunk('span', 'num', numberInSpan, [1])
+    ]);
+    var vnode2 = h('div', [
+      thunk('span', 'num', numberInSpan2, [1])
+    ]);
+    patch(vnode0, vnode1);
+    assert.equal(called, 1);
     patch(vnode1, vnode2);
-    patch(vnode2, vnode3);
     assert.equal(called, 2);
   });
   it('renders correctly', function() {