feat(gatsby-page-utils): extract logic for watching a directory from gatsby-page-creator so can reuse for custom page creation

packages/gatsby-page-utils/.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": [["babel-preset-gatsby-package", { "browser": true }]]
+}

packages/gatsby-page-utils/.gitignore

@@ -0,0 +1,32 @@
+# Logs
+logs
+*.log
+
+# Runtime data
+pids
+*.pid
+*.seed
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directory
+# https://www.npmjs.org/doc/misc/npm-faq.html#should-i-check-my-node_modules-folder-into-git
+node_modules
+
+decls
+dist
+
+/*.js

packages/gatsby-page-utils/README.md

@@ -0,0 +1,96 @@
+# gatsby-page-utils
+
+## Usage
+
+```sh
+npm install gatsby-page-utils
+```
+
+### Example
+
+```js
+const {
+  createPath,
+  ignorePath,
+  validatePath,
+  watchDirectory,
+} = require(`gatsby-page-utils`)
+
+// ...
+
+const pagesDirectory = "/pages"
+watchDirectory(
+  pagesDirectory,
+  "**/*.{js, jsx}",
+  addedPath => {
+    // Filter out special components that shouldn't be made into
+    // pages.
+    if (!validatePath(addedPath)) {
+      return
+    }
+
+    // Filter out anything matching the given ignore patterns and options
+    if (ignorePath(addedPath, "*/connexion")) {
+      return
+    }
+
+    // Create page object
+    const createdPath = createPath(addedPath)
+    const page = {
+      path: createdPath,
+      component: systemPath.join(pagesDirectory, addedPath),
+    }
+
+    // Add page
+    createPage(page)
+  },
+  removedPath => {
+    // Delete the page for the now deleted component.
+    const componentPath = systemPath.join(pagesDirectory, removedPath)
+    store.getState().pages.forEach(page => {
+      if (page.component === componentPath) {
+        deletePage({
+          path: createPath(removedPath),
+          component: componentPath,
+        })
+      }
+    })
+  }
+)
+```
+
+#### watchDirectory
+
+Watch activity on a directory and call functions each time a file is added or removed
+
+| property      | description                                     | type     |
+| ------------- | ----------------------------------------------- | -------- |
+| path          | Directory path in which pages are stored        | String   |
+| glob          | A glob that select files to watch               | String   |
+| onNewFile     | A function called each time a new file is added | Function |
+| onRemovedFile | A function called each time a file is removed   | Function |
+
+#### createPath
+
+Create a page path from a file path. It returns the page path.
+
+| property | description | type   |
+| -------- | ----------- | ------ |
+| path     | File path   | String |
+
+#### validatePath
+
+Validate a file path. It veryfies that it doesn't contains specific characters or strings. It returns `true` if path is valid otherwise it returns `false`.
+
+| property | description | type   |
+| -------- | ----------- | ------ |
+| path     | File path   | String |
+
+#### ignorePath
+
+Determines if path should be ignored regarding of a ignore pattern passed as parameter. It returns `true` if the passed path should be ignored otherwise it returns `false`.
+
+| property | description                       | type    |
+| -------- | --------------------------------- | ------- |
+| path     | File path                         | String  |
+| ignore   | A pattern to match with file path | (Object | String | Array) |

packages/gatsby-page-utils/package.json

@@ -0,0 +1,39 @@
+{
+  "name": "gatsby-page-utils",
+  "version": "0.0.1",
+  "description": "Gatsby library that helps creating pages",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "babel src --out-dir dist/ --ignore **/__tests__",
+    "watch": "babel -w src --out-dir dist/ --ignore **/__tests__",
+    "prepare": "cross-env NODE_ENV=production npm run build"
+  },
+  "keywords": [
+    "gatsby"
+  ],
+  "author": "Yvonnick FRIN <frin.yvonnick@gmail.com>",
+  "license": "MIT",
+  "repository": "https://github.com/gatsbyjs/gatsby/tree/master/packages/gatsby-page-utils",
+  "dependencies": {
+    "@babel/runtime": "^7.0.0",
+    "bluebird": "^3.5.0",
+    "chokidar": "2.1.2",
+    "fs-exists-cached": "^1.0.0",
+    "glob": "^7.1.1",
+    "lodash": "^4.17.10",
+    "micromatch": "^3.1.10",
+    "slash": "^1.0.0"
+  },
+  "devDependencies": {
+    "@babel/cli": "^7.0.0",
+    "@babel/core": "^7.0.0",
+    "babel-preset-gatsby-package": "^0.1.4",
+    "cross-env": "^5.0.5"
+  },
+  "peerDependencies": {
+    "gatsby": "^2.0.0"
+  },
+  "files": [
+    "dist/*"
+  ]
+}

packages/gatsby-plugin-page-creator/src/__tests__/__snapshots__/gatsby-node.js.snap → packages/gatsby-page-utils/src/__tests__/__snapshots__/create-path.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`JavaScript page creator create-path should create unix paths 1`] = `
+exports[`create-path should create unix paths 1`] = `
 Array [
   "/b/c/de/",
   "/bee/",

packages/gatsby-page-utils/src/__tests__/create-path.js

@@ -0,0 +1,9 @@
+const createPath = require(`../create-path`)
+
+describe(`create-path`, () => {
+  it(`should create unix paths`, () => {
+    const paths = [`b/c/de`, `bee`, `b/d/c/`]
+
+    expect(paths.map(p => createPath(p))).toMatchSnapshot()
+  })
+})

packages/gatsby-plugin-page-creator/src/__tests__/gatsby-node.js → packages/gatsby-page-utils/src/__tests__/validate-path.js

@@ -1,7 +1,6 @@
 const validatePath = require(`../validate-path`)
-const createPath = require(`../create-path`)
 
-describe(`JavaScript page creator`, () => {
+describe(`validatePath`, () => {
   it(`includes the correct file types`, () => {
     const validFiles = [
       { path: `test1.js` },
@@ -116,12 +115,4 @@ describe(`JavaScript page creator`, () => {
       validFiles
     )
   })
-
-  describe(`create-path`, () => {
-    it(`should create unix paths`, () => {
-      const paths = [`b/c/de`, `bee`, `b/d/c/`]
-
-      expect(paths.map(p => createPath(p))).toMatchSnapshot()
-    })
-  })
 })

packages/gatsby-plugin-page-creator/src/create-path.js → packages/gatsby-page-utils/src/create-path.js

@@ -1,5 +1,5 @@
 // @flow
-import path from "path"
+const path = require(`path`)
 
 module.exports = (filePath: string): string => {
   const { dir, name } = path.parse(filePath)

packages/gatsby-page-utils/src/index.js

@@ -0,0 +1,6 @@
+module.exports = {
+  validatePath: require(`./validate-path`),
+  createPath: require(`./create-path`),
+  ignorePath: require(`./ignore-path`),
+  watchDirectory: require(`./watch-directory`),
+}

packages/gatsby-page-utils/src/watch-directory.js

@@ -0,0 +1,18 @@
+const Promise = require(`bluebird`)
+const chokidar = require(`chokidar`)
+const slash = require(`slash`)
+
+module.exports = async (path, glob, onNewFile, onRemovedFile) =>
+  new Promise((resolve, reject) => {
+    chokidar
+      .watch(glob, { cwd: path })
+      .on(`add`, path => {
+        path = slash(path)
+        onNewFile(path)
+      })
+      .on(`unlink`, path => {
+        path = slash(path)
+        onRemovedFile(path)
+      })
+      .on(`ready`, () => resolve())
+  })

packages/gatsby-plugin-page-creator/package.json

@@ -21,12 +21,11 @@
   "dependencies": {
     "@babel/runtime": "^7.0.0",
     "bluebird": "^3.5.0",
-    "chokidar": "2.1.2",
     "fs-exists-cached": "^1.0.0",
+    "gatsby-page-utils": "^0.0.1",
     "glob": "^7.1.1",
     "lodash": "^4.17.10",
-    "micromatch": "^3.1.10",
-    "slash": "^1.0.0"
+    "micromatch": "^3.1.10"
   },
   "devDependencies": {
     "@babel/cli": "^7.0.0",

packages/gatsby-plugin-page-creator/src/gatsby-node.js

@@ -1,16 +1,17 @@
 const globCB = require(`glob`)
 const Promise = require(`bluebird`)
 const _ = require(`lodash`)
-const chokidar = require(`chokidar`)
 const systemPath = require(`path`)
 const existsSync = require(`fs-exists-cached`).sync
 
 const glob = Promise.promisify(globCB)
 
-const createPath = require(`./create-path`)
-const validatePath = require(`./validate-path`)
-const ignorePath = require(`./ignore-path`)
-const slash = require(`slash`)
+const {
+  createPath,
+  validatePath,
+  ignorePath,
+  watchDirectory,
+} = require(`gatsby-page-utils`)
 
 // Path creator.
 // Auto-create pages.
@@ -56,31 +57,29 @@ exports.createPagesStatefully = async (
   let files = await glob(pagesGlob, { cwd: pagesPath })
   files.forEach(file => _createPage(file, pagesDirectory, createPage, ignore))
 
-  // Listen for new component pages to be added or removed.
-  chokidar
-    .watch(pagesGlob, { cwd: pagesPath })
-    .on(`add`, path => {
-      path = slash(path)
-      if (!_.includes(files, path)) {
-        _createPage(path, pagesDirectory, createPage, ignore)
-        files.push(path)
+  watchDirectory(
+    pagesPath,
+    pagesGlob,
+    addedPath => {
+      if (!_.includes(files, addedPath)) {
+        _createPage(addedPath, pagesDirectory, createPage, ignore)
+        files.push(addedPath)
       }
-    })
-    .on(`unlink`, path => {
-      path = slash(path)
+    },
+    removedPath => {
       // Delete the page for the now deleted component.
+      const componentPath = systemPath.join(pagesDirectory, removedPath)
       store.getState().pages.forEach(page => {
-        const componentPath = systemPath.join(pagesDirectory, path)
         if (page.component === componentPath) {
           deletePage({
-            path: createPath(path),
+            path: createPath(removedPath),
             component: componentPath,
           })
         }
       })
-      files = files.filter(f => f !== path)
-    })
-    .on(`ready`, () => doneCb())
+      files = files.filter(f => f !== removedPath)
+    }
+  ).then(() => doneCb())
 }
 const _createPage = (filePath, pagesDirectory, createPage, ignore) => {
   // Filter out special components that shouldn't be made into