Change the way the dynamic host driver function is created

Author: vfeskov

README.md

@@ -64,13 +64,13 @@ Looks like this:
 
 ![img](http://i.imgur.com/1LCZxrg.png)
 
-<a id="makeDynamicHostCanvasDriverExample"></a>
+<a id="canvasDriverExample"></a>
 Or in case the canvas element appears later, for example, when it's created by DOM driver:
 
 ```jsx
 import {run} from '@cycle/rxjs-run';
 import {makeDOMDriver} from '@cycle/dom'
-import {makeDynamicHostCanvasDriver, rect} from 'cycle-canvas';
+import {canvasDriver, rect} from 'cycle-canvas';
 import {Observable} from 'rxjs'
 
 function main (sources) {
@@ -94,7 +94,7 @@ function main (sources) {
 
 const drivers = {
   DOM: makeDOMDriver('body'),
-  Canvas: makeDynamicHostCanvasDriver()
+  Canvas: canvasDriver
 };
 
 run(main, drivers);
@@ -109,7 +109,7 @@ You can find the source for flappy bird [here](https://github.com/cyclejs-commun
 #### Creating a canvas driver
 
 - [`makeCanvasDriver`](#makeCanvasDriver)
-- [`makeDynamicHostCanvasDriver`](#makeDynamicHostCanvasDriver)
+- [`canvasDriver`](#canvasDriver)
 
 #### Drawing shapes and text
 
@@ -181,11 +181,11 @@ const drivers = {
 run(main, drivers);
 ```
 
-### <a id="makeDynamicHostCanvasDriver"></a> `makeDynamicHostCanvasDriver()`
+### <a id="canvasDriver"></a> `canvasDriver`
 
-An alternative factory for the canvas driver function.
+An alternative canvas driver function to be used directly without a factory.
 
-Does not take any arguments, but requires events in the sink to be of this format:
+It requires events in the sink to be of this format:
 ```js
 {
   hostCanvas
@@ -194,7 +194,7 @@ Does not take any arguments, but requires events in the sink to be of this forma
 ```
 where `hostCanvas` is a `<canvas>` DOM element and `rootElement` is the element to draw on the `hostCanvas`.
 
-You can find an [example](#makeDynamicHostCanvasDriverExample) at the top.
+You can find an [example](#canvasDriverExample) at the top.
 
 ## Drawing shapes and text
 

src/canvas-driver.js

@@ -433,29 +433,25 @@ export function makeCanvasDriver (selector, canvasSize = null) {
   return driver
 }
 
-export function makeDynamicHostCanvasDriver () {
-  let driver = function dynamicHostCanvasDriver (sink$) {
-    sink$.addListener({
-      next: ({hostCanvas, rootElement}) => {
-        const context = hostCanvas.getContext('2d')
-
-        const rootElementWithDefaults = getRootElementWithDefaults(hostCanvas, rootElement)
+export function canvasDriver (sink$) {
+  sink$.addListener({
+    next: ({hostCanvas, rootElement}) => {
+      const context = hostCanvas.getContext('2d')
 
-        const instructions = translateVtreeToInstructions(rootElementWithDefaults)
+      const rootElementWithDefaults = getRootElementWithDefaults(hostCanvas, rootElement)
 
-        renderInstructionsToCanvas(instructions, context)
-      },
-      error: e => { throw e },
-      complete: () => null
-    })
+      const instructions = translateVtreeToInstructions(rootElementWithDefaults)
 
-    return adapt(xs.empty())
-  }
+      renderInstructionsToCanvas(instructions, context)
+    },
+    error: e => { throw e },
+    complete: () => null
+  })
 
-  return driver
+  return adapt(xs.empty())
 }
 
-function getRootElementWithDefaults(hostCanvas, rootElement) {
+function getRootElementWithDefaults (hostCanvas, rootElement) {
   const defaults = {
     kind: 'rect',
     x: 0,

test/driver-test.js

@@ -1,5 +1,5 @@
 /* globals describe, it */
-import {translateVtreeToInstructions, renderInstructionsToCanvas, rect, line, arc, text, polygon, image, makeCanvasDriver, makeDynamicHostCanvasDriver} from '../src/canvas-driver'
+import {translateVtreeToInstructions, renderInstructionsToCanvas, rect, line, arc, text, polygon, image, makeCanvasDriver, canvasDriver} from '../src/canvas-driver'
 import assert from 'assert'
 import root from 'window-or-global'
 import {JSDOM} from 'jsdom'
@@ -12,7 +12,7 @@ function methodSpy () {
   const stub = (...args) => {
     called += 1
     callArgs.push(args)
-  };
+  }
 
   stub.callCount = () => called
   stub.callArgs = () => callArgs
@@ -964,8 +964,8 @@ describe('canvasDriver', () => {
     })
   })
 
-  describe('makeDynamicHostCanvasDriver', () => {
-    it('produces a canvas driver, a sink to which must emit hostCanvas DOM element along with rootElement to draw on that canvas', () => {
+  describe('canvasDriver', () => {
+    it('is a canvas driver function, a sink to which must emit hostCanvas DOM element along with rootElement to draw on that hostCanvas', () => {
       const jsdom = new JSDOM('<!DOCTYPE html><html><body><canvas width="100" height="100"></canvas></body></html>')
 
       const actualContextOperations = []
@@ -987,7 +987,7 @@ describe('canvasDriver', () => {
         rootElement
       })
 
-      makeDynamicHostCanvasDriver()(vcanvas$)
+      canvasDriver(vcanvas$)
 
       const expectedContextOperations = [
         {call: 'save', args: []},
@@ -1001,7 +1001,7 @@ describe('canvasDriver', () => {
     })
   })
 
-  function mockContext(operationCallback) {
+  function mockContext (operationCallback) {
     return new Proxy({}, {
       get: (_, methodName) => {
         return (...args) => operationCallback({