addon-storysource would throw compile error 'addSourceDecorator is not a function' when import after named export

[jackysee]

Describe the bug
When writing story in CSF with import statement appear after first named export, it will throw compile error.

To Reproduce
Steps to reproduce the behavior:

1. Clone the demo repo https://github.com/jackysee/storysource-order
2. npm install and npm run storybook
3. Open browser http://localhost:6006
4. See error

Expected behavior
It should compile fine. When @storybook/addon-storysource is not installed, the stories can be compiled and shown correctly.

Screenshots

TypeError: addSourceDecorator is not a function
    at Module../src/components/MyButton.stories.js (http://localhost:6006/main.da02c91890c0d533134b.bundle.js:245:14)
    at __webpack_require__ (http://localhost:6006/runtime~main.da02c91890c0d533134b.bundle.js:786:30)
    at fn (http://localhost:6006/runtime~main.da02c91890c0d533134b.bundle.js:151:20)
    at webpackContext (http://localhost:6006/main.da02c91890c0d533134b.bundle.js:95:9)
    at http://localhost:6006/vendors~main.da02c91890c0d533134b.bundle.js:4727:31
    at Array.forEach (<anonymous>)
    at http://localhost:6006/vendors~main.da02c91890c0d533134b.bundle.js:4726:22
    at Array.forEach (<anonymous>)
    at http://localhost:6006/vendors~main.da02c91890c0d533134b.bundle.js:4725:14
    at render (http://localhost:6006/vendors~main.da02c91890c0d533134b.bundle.js:1897:13)

Code snippets

export default { title: "MyButton" };

import MyButton from "./MyButton.vue";
export const button = () => ({
  components: { MyButton },
  template: `<MyButton>Hi</MyButton>`
});

import Icon from "./Icon.vue";
export const WithIcon = () => ({
  components: { MyButton, Icon },
  template: `<MyButton><Icon/>Hello</MyButton>`
});

System:

Environment Info:

  System:
    OS: Linux 4.4 Ubuntu 18.04.3 LTS (Bionic Beaver)
    CPU: (4) x64 Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz
  Binaries:
    Node: 12.13.0 - /tmp/fnm-shell-3449273/bin/node
    Yarn: 1.16.0 - /mnt/c/Users/jackys/scoop/apps/nvm/current/nodejs/nodejs/yarn
    npm: 6.13.6 - /tmp/fnm-shell-3449273/bin/npm
  npmPackages:
    @storybook/addon-actions: ^5.3.4 => 5.3.4
    @storybook/addon-links: ^5.3.4 => 5.3.4
    @storybook/addon-storysource: ^5.3.4 => 5.3.4
    @storybook/addons: ^5.3.4 => 5.3.4
    @storybook/vue: ^5.3.4 => 5.3.4

Additional context
The source as seen in devtools, you can see the addSourceDecorator is put lower than the calling code.

export default {parameters: {"storySource":{"source":"export default { title: \"MyButton\" };\n\nimport MyButton from \"./MyButton.vue\";\n\nexport const button = () => ({\n  components: { MyButton },\n  template: `<MyButton>Hi</MyButton>`\n});\n\nimport Icon from \"./Icon.vue\";\nexport const WithIcon = () => ({\n  components: { MyButton, Icon },\n  template: `<MyButton><Icon/>Hello</MyButton>`\n});\n","locationsMap":{"mybutton--button":{"startLoc":{"col":22,"line":5},"endLoc":{"col":2,"line":8},"startBody":{"col":22,"line":5},"endBody":{"col":2,"line":8}},"mybutton--with-icon":{"startLoc":{"col":24,"line":11},"endLoc":{"col":2,"line":14},"startBody":{"col":24,"line":11},"endBody":{"col":2,"line":14}}}},}, title: "MyButton" };

import MyButton from "./MyButton.vue";

export const button = addSourceDecorator(() => ({
  components: { MyButton },
  template: `<MyButton>Hi</MyButton>`
}), {__STORY__, __ADDS_MAP__,__MAIN_FILE_LOCATION__,__MODULE_DEPENDENCIES__,__LOCAL_DEPENDENCIES__,__SOURCE_PREFIX__,__IDS_TO_FRAMEWORKS__});;

import Icon from "./Icon.vue";

/* eslint-disable */
// @ts-ignore
var withSourceLoader = require('@storybook/source-loader/preview').withSource;
// @ts-ignore
var addSourceDecorator = require("@storybook/source-loader/preview").addSource;
// @ts-ignore
var __SOURCE_PREFIX__ = "/home/jackys/works/storybook/storysource-order/src/components";
// @ts-ignore
var __STORY__ = "export default { title: \"MyButton\" };\n\nimport MyButton from \"./MyButton.vue\";\n\nexport const button = () => ({\n  components: { MyButton },\n  template: `<MyButton>Hi</MyButton>`\n});\n\nimport Icon from \"./Icon.vue\";\nexport const WithIcon = () => ({\n  components: { MyButton, Icon },\n  template: `<MyButton><Icon/>Hello</MyButton>`\n});\n";
// @ts-ignore
var __ADDS_MAP__ = {"mybutton--button":{"startLoc":{"col":22,"line":5},"endLoc":{"col":2,"line":8},"startBody":{"col":22,"line":5},"endBody":{"col":2,"line":8}},"mybutton--with-icon":{"startLoc":{"col":24,"line":11},"endLoc":{"col":2,"line":14},"startBody":{"col":24,"line":11},"endBody":{"col":2,"line":14}}};
// @ts-ignore
var __MAIN_FILE_LOCATION__ = "/MyButton.stories.js";
// @ts-ignore
var __MODULE_DEPENDENCIES__ = [];
// @ts-ignore
var __LOCAL_DEPENDENCIES__ = {};
// @ts-ignore
var __IDS_TO_FRAMEWORKS__ = {};
        

export const WithIcon = addSourceDecorator(() => ({
  components: { MyButton, Icon },
  template: `<MyButton><Icon/>Hello</MyButton>`
}), {__STORY__, __ADDS_MAP__,__MAIN_FILE_LOCATION__,__MODULE_DEPENDENCIES__,__LOCAL_DEPENDENCIES__,__SOURCE_PREFIX__,__IDS_TO_FRAMEWORKS__});

[shilman]

Shiver me timbers!! I just released https://github.com/storybookjs/storybook/releases/tag/v5.3.5 containing PR #9492 that references this issue. Upgrade today to try it out!

Closing this issue. Please re-open if you think there's still more to do.