if page's matchPath is altered, loader.js cannot find the page

[alpgumus]

Description

If page's matchPath property is altered in gatsby-node.js, loader.js is not able to find the page in development mode.

Steps to reproduce

in gatsby-node.js, change matchPath of a page:

exports.onCreatePage = ({ page, actions }) => {
  const { createPage } = actions
  if (page.path === `/mypage/`) {
    page.matchPath = `/mypath/*`
    createPage(page)
  } 
}

Expected result

When you browse to /mypath mypage should display

Actual result

In development mode, it is not able to find the page, and showing 404

Check this note: note by pieh by @pieh

There is no need to findPage here as page is already in scope or do findPage by matchPath if it is set

// loader.js
if (process.env.NODE_ENV !== `production`) {
        const page = findPage(path)
        const pageResources = {
          component: syncRequires.components[page.componentChunkName],
          page,
        }
...
}

Environment

System:
OS: macOS Sierra 10.12.6
CPU: x64 Intel(R) Core(TM) i5-5287U CPU @ 2.90GHz
Shell: 5.2 - /bin/zsh
Binaries:
Node: 9.7.1 - ~/.nvm/versions/node/v9.7.1/bin/node
Yarn: 1.5.1 - /usr/local/bin/yarn
npm: 6.0.0 - ~/.nvm/versions/node/v9.7.1/bin/npm
Browsers:
Chrome: 67.0.3396.99
Firefox: 57.0.4
Safari: 11.0.1
npmPackages:
gatsby: 2.0.1 => 2.0.1
gatsby-cli: 2.0.1 => 2.0.1

[kakadiadarpan]

Thanks for the quick PR @alpgumus 😄

[pieh]

Should be fixed in gatsby@2.0.4