feat(compiler-sfc): transform srcset (#501)

packages/compiler-sfc/__tests__/__snapshots__/templateTransformSrcset.spec.ts.snap

@@ -0,0 +1,49 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`compiler sfc: transform srcset transform srcset 1`] = `
+"import { createVNode, createBlock, Fragment, openBlock } from \\"vue\\"
+import _imports_0 from './logo.png'
+
+
+const _hoisted_1 = _imports_0
+const _hoisted_2 = _imports_0 + '2x'
+const _hoisted_3 = _imports_0 + '2x'
+const _hoisted_4 = _imports_0 + ', ' + _imports_0 + '2x'
+const _hoisted_5 = _imports_0 + '2x, ' + _imports_0
+const _hoisted_6 = _imports_0 + '2x, ' + _imports_0 + '3x'
+const _hoisted_7 = _imports_0 + ', ' + _imports_0 + '2x, ' + _imports_0 + '3x'
+
+export default function render() {
+  const _ctx = this
+  return (openBlock(), createBlock(Fragment, null, [
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_1
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_2
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_3
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_4
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_5
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_6
+    }),
+    createVNode(\\"img\\", {
+      src: \\"./logo.png\\",
+      srcset: _hoisted_7
+    })
+  ]))
+}"
+`;

packages/compiler-sfc/__tests__/templateTransformSrcset.spec.ts

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+import { generate, parse, transform } from '@vue/compiler-core'
+import { transformSrcset } from '../src/templateTransformSrcset'
+import { transformElement } from '../../compiler-core/src/transforms/transformElement'
+import { transformBind } from '../../compiler-core/src/transforms/vBind'
+
+function compileWithSrcset(template: string) {
+  const ast = parse(template)
+  transform(ast, {
+    nodeTransforms: [transformSrcset, transformElement],
+    directiveTransforms: {
+      bind: transformBind
+    }
+  })
+  return generate(ast, { mode: 'module' })
+}
+
+describe('compiler sfc: transform srcset', () => {
+  test('transform srcset', () => {
+    const result = compileWithSrcset(`
+			<img src="./logo.png" srcset="./logo.png"/>
+			<img src="./logo.png" srcset="./logo.png 2x"/>
+			<img src="./logo.png" srcset="./logo.png 2x"/>
+			<img src="./logo.png" srcset="./logo.png, ./logo.png 2x"/>
+			<img src="./logo.png" srcset="./logo.png 2x, ./logo.png"/>
+			<img src="./logo.png" srcset="./logo.png 2x, ./logo.png 3x"/>
+			<img src="./logo.png" srcset="./logo.png, ./logo.png 2x, ./logo.png 3x"/>
+		`)
+
+    expect(result.code).toMatchSnapshot()
+  })
+})