Addon-docs: Dynamic source rendering for Vue

addons/docs/package.json

@@ -70,6 +70,7 @@
     "html-tags": "^3.1.0",
     "js-string-escape": "^1.0.1",
     "lodash": "^4.17.15",
+    "prettier": "~2.0.5",
     "prop-types": "^15.7.2",
     "react": "^16.8.3",
     "react-dom": "^16.8.3",
@@ -106,7 +107,6 @@
     "jest-specific-snapshot": "^4.0.0",
     "lit-element": "^2.2.1",
     "lit-html": "^1.0.0",
-    "prettier": "~2.0.5",
     "require-from-string": "^2.0.2",
     "rxjs": "^6.5.4",
     "styled-components": "^5.0.1",

addons/docs/src/frameworks/vue/config.ts

@@ -1,6 +1,7 @@
 import { extractArgTypes } from './extractArgTypes';
 import { extractComponentDescription } from '../../lib/docgen';
 import { prepareForInline } from './prepareForInline';
+import { sourceDecorator } from './sourceDecorator';
 
 export const parameters = {
   docs: {
@@ -10,3 +11,5 @@ export const parameters = {
     extractComponentDescription,
   },
 };
+
+export const decorators = [sourceDecorator];

addons/docs/src/frameworks/vue/sourceDecorator.test.ts

@@ -0,0 +1,77 @@
+/* eslint no-underscore-dangle: ["error", { "allow": ["_vnode"] }] */
+
+import { ComponentOptions } from 'vue';
+import Vue from 'vue/dist/vue';
+import { vnodeToString } from './sourceDecorator';
+
+expect.addSnapshotSerializer({
+  print: (val: any) => val,
+  test: (val) => typeof val === 'string',
+});
+
+const getVNode = (Component: ComponentOptions<any, any, any>) => {
+  const vm = new Vue({
+    render(h: (c: any) => unknown) {
+      return h(Component);
+    },
+  }).$mount();
+
+  return vm.$children[0]._vnode;
+};
+
+describe('vnodeToString', () => {
+  it('basic', () => {
+    expect(
+      vnodeToString(
+        getVNode({
+          template: `<button>Button</button>`,
+        })
+      )
+    ).toMatchInlineSnapshot(`<button >Button</button>`);
+  });
+
+  it('attributes', () => {
+    const MyComponent: ComponentOptions<any, any, any> = {
+      props: ['propA', 'propB', 'propC', 'propD'],
+      template: '<div/>',
+    };
+
+    expect(
+      vnodeToString(
+        getVNode({
+          components: { MyComponent },
+          data(): { props: Record<string, any> } {
+            return {
+              props: {
+                propA: 'propA',
+                propB: 1,
+                propC: null,
+                propD: {
+                  foo: 'bar',
+                },
+              },
+            };
+          },
+          template: `<my-component v-bind="props"/>`,
+        })
+      )
+    ).toMatchInlineSnapshot(
+      `<my-component :propD='{"foo":"bar"}' :propC="null" :propB="1" propA="propA"/>`
+    );
+  });
+
+  it('children', () => {
+    expect(
+      vnodeToString(
+        getVNode({
+          template: `
+          <div>
+            <form>
+              <button>Button</button>
+            </form>
+          </div>`,
+        })
+      )
+    ).toMatchInlineSnapshot(`<div ><form ><button >Button</button></form></div>`);
+  });
+});

addons/docs/src/frameworks/vue/sourceDecorator.ts

@@ -0,0 +1,198 @@
+/* eslint no-underscore-dangle: ["error", { "allow": ["_vnode"] }] */
+
+import { addons, StoryContext } from '@storybook/addons';
+import { logger } from '@storybook/client-logger';
+import prettier from 'prettier/standalone';
+import prettierHtml from 'prettier/parser-html';
+import Vue from 'vue';
+
+import { SourceType, SNIPPET_RENDERED } from '../../shared';
+
+export const skipSourceRender = (context: StoryContext) => {
+  const sourceParams = context?.parameters.docs?.source;
+  const isArgsStory = context?.parameters.__isArgsStory;
+
+  // always render if the user forces it
+  if (sourceParams?.type === SourceType.DYNAMIC) {
+    return false;
+  }
+
+  // never render if the user is forcing the block to render code, or
+  // if the user provides code, or if it's not an args story.
+  return !isArgsStory || sourceParams?.code || sourceParams?.type === SourceType.CODE;
+};
+
+export const sourceDecorator = (storyFn: any, context: StoryContext) => {
+  const story = storyFn();
+
+  // See ../react/jsxDecorator.tsx
+  if (skipSourceRender(context)) {
+    return story;
+  }
+
+  try {
+    // Creating a Vue instance each time is very costly. But we need to do it
+    // in order to access VNode, otherwise vm.$vnode will be undefined.
+    // Also, I couldn't see any notable difference from the implementation with
+    // per-story-cache.
+    // But if there is a more performant way, we should replace it with that ASAP.
+    const vm = new Vue({
+      data() {
+        return {
+          STORYBOOK_VALUES: context.args,
+        };
+      },
+      render(h) {
+        return h(story);
+      },
+    }).$mount();
+
+    const channel = addons.getChannel();
+
+    const storyComponent = getStoryComponent(story.options.STORYBOOK_WRAPS);
+
+    const storyNode = lookupStoryInstance(vm, storyComponent);
+
+    const code = vnodeToString(storyNode._vnode);
+
+    channel.emit(
+      SNIPPET_RENDERED,
+      (context || {}).id,
+      prettier.format(`<template>${code}</template>`, {
+        parser: 'vue',
+        plugins: [prettierHtml],
+        // Because the parsed vnode missing spaces right before/after the surround tag,
+        // we always get weird wrapped code without this option.
+        htmlWhitespaceSensitivity: 'ignore',
+      })
+    );
+  } catch (e) {
+    logger.warn(`Failed to generate dynamic story source: ${e}`);
+  }
+
+  return story;
+};
+
+export function vnodeToString(vnode: Vue.VNode): string {
+  const attrString = [
+    ...(vnode.data?.slot ? ([['slot', vnode.data.slot]] as [string, any][]) : []),
+    ...(vnode.componentOptions?.propsData ? Object.entries(vnode.componentOptions.propsData) : []),
+    ...(vnode.data?.attrs ? Object.entries(vnode.data.attrs) : []),
+  ]
+    .filter(([name], index, list) => list.findIndex((item) => item[0] === name) === index)
+    .map(([name, value]) => stringifyAttr(name, value))
+    .filter(Boolean)
+    .join(' ');
+
+  if (!vnode.componentOptions) {
+    // Non-component elements (div, span, etc...)
+    if (vnode.tag) {
+      if (!vnode.children) {
+        return `<${vnode.tag} ${attrString}/>`;
+      }
+
+      return `<${vnode.tag} ${attrString}>${vnode.children.map(vnodeToString).join('')}</${
+        vnode.tag
+      }>`;
+    }
+
+    // TextNode
+    if (vnode.text) {
+      if (/[<>"&]/.test(vnode.text)) {
+        return `{{\`${vnode.text.replace(/`/g, '\\`')}\`}}`;
+      }
+
+      return vnode.text;
+    }
+
+    // Unknown
+    return '';
+  }
+
+  // Probably users never see the "unknown-component". It seems that vnode.tag
+  // is always set.
+  const tag = vnode.componentOptions.tag || vnode.tag || 'unknown-component';
+
+  if (!vnode.componentOptions.children) {
+    return `<${tag} ${attrString}/>`;
+  }
+
+  return `<${tag} ${attrString}>${vnode.componentOptions.children
+    .map(vnodeToString)
+    .join('')}</${tag}>`;
+}
+
+function stringifyAttr(attrName: string, value?: any): string | null {
+  if (typeof value === 'undefined') {
+    return null;
+  }
+
+  if (value === true) {
+    return attrName;
+  }
+
+  if (typeof value === 'string') {
+    return `${attrName}=${quote(value)}`;
+  }
+
+  // TODO: Better serialization (unquoted object key, Symbol/Classes, etc...)
+  //       Seems like Prettier don't format JSON-look object (= when keys are quoted)
+  return `:${attrName}=${quote(JSON.stringify(value))}`;
+}
+
+function quote(value: string) {
+  return value.includes(`"`) && !value.includes(`'`)
+    ? `'${value}'`
+    : `"${value.replace(/"/g, '&quot;')}"`;
+}
+
+/**
+ * Skip decorators and grab a story component itself.
+ * https://github.com/pocka/storybook-addon-vue-info/pull/113
+ */
+function getStoryComponent(w: any) {
+  let matched = w;
+
+  while (
+    matched &&
+    matched.options &&
+    matched.options.components &&
+    matched.options.components.story &&
+    matched.options.components.story.options &&
+    matched.options.components.story.options.STORYBOOK_WRAPS
+  ) {
+    matched = matched.options.components.story.options.STORYBOOK_WRAPS;
+  }
+  return matched;
+}
+
+interface VueInternal {
+  // We need to access this private property, in order to grab the vnode of the
+  // component instead of the "vnode of the parent of the component".
+  // Probably it's safe to rely on this because vm.$vnode is a reference for this.
+  // https://github.com/vuejs/vue/issues/6070#issuecomment-314389883
+  _vnode: Vue.VNode;
+}
+
+/**
+ * Find the story's instance from VNode tree.
+ */
+function lookupStoryInstance(instance: Vue, storyComponent: any): (Vue & VueInternal) | null {
+  if (
+    instance.$vnode &&
+    instance.$vnode.componentOptions &&
+    instance.$vnode.componentOptions.Ctor === storyComponent
+  ) {
+    return instance as Vue & VueInternal;
+  }
+
+  for (let i = 0, l = instance.$children.length; i < l; i += 1) {
+    const found = lookupStoryInstance(instance.$children[i], storyComponent);
+
+    if (found) {
+      return found;
+    }
+  }
+
+  return null;
+}

addons/docs/src/typings.d.ts

@@ -7,6 +7,7 @@ declare module 'babel-plugin-react-docgen';
 declare module 'require-from-string';
 declare module 'styled-components';
 declare module 'acorn-jsx';
+declare module 'vue/dist/vue';
 
 declare module 'sveltedoc-parser' {
   export function parse(options: any): Promise<any>;