feat(vdom): remove support for null nodes returned from mapIterable()

Useless feature, it is easy to generate next node instead of returning null node.
localvoid · May 31, 2018 · e3c88a5 · e3c88a5
1 parent 5c75401
commit e3c88a5
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Showing 3 changed files with 21 additions and 48 deletions.
diff --git a/packages/ivi/src/vdom/__tests__/vnode_collections_iterator.spec.ts b/packages/ivi/src/vdom/__tests__/vnode_collections_iterator.spec.ts
@@ -1,9 +1,11 @@
-import { mapIterable, VNodeFlags, fragment } from "ivi";
+import { mapIterable, VNodeFlags, fragment, VNode } from "ivi";
 import * as h from "ivi-html";
 
 test(`null`, () => {
   expect(mapIterable(function* () {
-    yield null;
+    if (0) {
+      yield h.div();
+    }
   }())).toBeNull();
 });
 
@@ -37,34 +39,6 @@ test(`two nodes`, () => {
   expect(v2._r).toBeNull();
 });
 
-test(`first null`, () => {
-  const v1 = h.div().k(5);
-
-  const first = mapIterable(function* () {
-    yield null;
-    yield v1;
-  }());
-
-  expect(first).toBe(v1);
-  expect(v1._f & VNodeFlags.KeyedList).toBeTruthy();
-  expect(v1._l).toBe(v1);
-  expect(v1._r).toBeNull();
-});
-
-test(`second null`, () => {
-  const v1 = h.div().k(5);
-
-  const first = mapIterable(function* () {
-    yield v1;
-    yield null;
-  }());
-
-  expect(first).toBe(v1);
-  expect(v1._f & VNodeFlags.KeyedList).toBeTruthy();
-  expect(v1._l).toBe(v1);
-  expect(v1._r).toBeNull();
-});
-
 test(`raise an exception when VNode doesn't have an explicit key (first node)`, () => {
   expect(() => {
     mapIterable((function* () {
@@ -85,7 +59,7 @@ test(`raise an exception when VNode doesn't have an explicit key (second node)`,
 test(`raise an exception when function returns children collection`, () => {
   expect(() => {
     mapIterable(function* () {
-      yield fragment(h.div().k(0), h.div().k(1));
+      yield fragment(h.div().k(0), h.div().k(1)) as VNode;
     }());
   }).toThrowError("singular");
 });
diff --git a/packages/ivi/src/vdom/vnode_collections.ts b/packages/ivi/src/vdom/vnode_collections.ts
@@ -194,29 +194,27 @@ export function mapRange<T>(start: number, end: number, fn: (idx: number) => VNo
  * @param iterable - Iterable iterator
  * @returns Virtual DOM collection
  */
-export function mapIterable<T>(iterable: IterableIterator<VNode<T> | null>): VNode<T> | null {
+export function mapIterable<T>(iterable: IterableIterator<VNode<T>>): VNode<T> | null {
   let first: VNode<any> | null = null;
   let prev: VNode<any> | null = null;
 
   for (const n of iterable) {
-    if (n !== null) {
-      /* istanbul ignore else */
-      if (DEBUG) {
-        if ((n._f & VNodeFlags.Key) === 0) {
-          throw new Error(`VNodes created with a mapIterable() function should have an explicit key`);
-        }
-        if (n._l !== n) {
-          throw new Error(`VNodes created with a mapIterable() function should be a singular nodes`);
-        }
+    /* istanbul ignore else */
+    if (DEBUG) {
+      if ((n._f & VNodeFlags.Key) === 0) {
+        throw new Error(`VNodes created with a mapIterable() function should have an explicit key`);
       }
-      if (prev !== null) {
-        n._l = prev;
-        prev._r = n;
-      } else {
-        first = n;
+      if (n._l !== n) {
+        throw new Error(`VNodes created with a mapIterable() function should be a singular nodes`);
       }
-      prev = n;
     }
+    if (prev !== null) {
+      n._l = prev;
+      prev._r = n;
+    } else {
+      first = n;
+    }
+    prev = n;
   }
 
   if (first !== null) {

diff --git a/packages/ivi/tsconfig.build.module.json b/packages/ivi/tsconfig.build.module.json
@@ -3,6 +3,7 @@
   "compilerOptions": {
     "target": "es5",
     "module": "es2015",
-    "outDir": "dist/module"
+    "outDir": "dist/module",
+    "downlevelIteration": true
   }
 }