Merge pull request #1 from primer/alias-rules

Support path aliases via rules.json

README.md

@@ -1,11 +1,16 @@
 # primer/deploy
-This [GitHub Action][github actions] deploys to [Now] and aliases the successful deployment to either:
 
-* The `alias` field in `now.json` if the branch is `master`; or
-* A branch-specific URL in the form `{name}-{branch}.now.sh`, where:
-    * `{name}` is your app's name (in `now.json`, `package.json`, or the name of the directory);
-    * `{branch}` is the part after `refs/heads/` in the `GITHUB_REF` [environment variable](https://developer.github.com/actions/creating-github-actions/accessing-the-runtime-environment/#environment-variables); and
-    * Both strings are normalized in the alias to trim any leading non-alphanumeric characters and replace any sequence of non-alphanumeric characters with a single `-`.
+This [GitHub Action][github actions] deploys to [Now] and aliases the successful deployment to a predictable URL according to the following conditions:
+
+1. We run `now` without any arguments to get the "root" deployment URL, which is generated by Now.
+1. If the branch is `master`, we treat the `alias` field in `now.json` as the production URL and:
+    1. If there is a `rules.json`:
+        * `now alias <deployment> <name>.now.sh` to create a fallback URL for path aliases
+        * `now alias <deployment> <production> -r rules.json` to set up path aliases
+    1. `now alias <deployment> <production>` to alias the production URL.
+1. `now alias <deployment> <name>-<branch>.now.sh` to alias the root deployment to a branch-specific URL.
+
+The app name (`<name>`) and branch (`<branch>`) are both "slugified" to strip invalid characters so that they'll work as URLs. Leading non-word characters are removed, and any sequence of characters that isn't alphanumeric or `-` is replaced with a single `-`. In other words, `@primer/css` becomes `primer-css`, `shawnbot/some_branch` becomes `shawnbot-some-branch`, and so on.
 
 ## Status checks
 Two [status checks] will be listed for this action in your checks: **deploy** is the action's check, and **deploy/alias** is a [commit status] created by the action that reports the URL and links to it via "Details":
@@ -33,7 +38,8 @@ action "deploy" {
 
 To avoid racking up failed deployments, we suggest that you place this action after any linting and test actions.
 
+
 [now]: https://zeit.co/now
 [github actions]: https://github.com/features/actions
 [commit status]: https://developer.github.com/v3/repos/statuses/
-[status checks]: https://help.github.com/articles/about-status-checks/
+[status checks]: https://help.github.com/articles/about-status-checks/

src/__tests__/deploy.js

@@ -0,0 +1,138 @@
+const mockedEnv = require('mocked-env')
+const readJSON = require('../read-json')
+const deploy = require('../deploy')
+const now = require('../now')
+const commitStatus = require('../commit-status')
+
+jest.mock('../now')
+jest.mock('../read-json')
+jest.mock('../commit-status')
+
+commitStatus.mockImplementation(() => Promise.resolve({}))
+
+describe('deploy()', () => {
+  let restoreEnv = () => {}
+  afterEach(() => {
+    restoreEnv()
+    // clear the call data
+    now.mockReset()
+    // restore the original behavior
+    readJSON.mockReset()
+  })
+
+  it('calls now() once when w/o an alias', () => {
+    mockFiles({
+      'package.json': {name: 'foo'},
+      'now.json': {},
+      'rules.json': null
+    })
+
+    const url = 'foo-123.now.sh'
+    now.mockImplementation(() => Promise.resolve(url))
+    mockEnv({GITHUB_REF: ''})
+
+    return deploy().then(res => {
+      expect(now).toHaveBeenCalledTimes(1)
+      expect(now).toHaveBeenCalledWith()
+      expect(res).toEqual({name: 'foo', root: url, url})
+    })
+  })
+
+  it('deploys to a branch alias on branches other than master', () => {
+    mockFiles({
+      'package.json': {name: 'foo'},
+      'now.json': {},
+      'rules.json': null
+    })
+
+    const url = 'foo-123.now.sh'
+    const alias = 'foo-bar.now.sh'
+    now.mockImplementation(() => Promise.resolve(url))
+    mockEnv({GITHUB_REF: 'refs/heads/bar'})
+
+    return deploy().then(res => {
+      expect(now).toHaveBeenCalledTimes(2)
+      expect(now).toHaveBeenNthCalledWith(1)
+      expect(now).toHaveBeenNthCalledWith(2, ['alias', url, alias])
+      expect(res).toEqual({name: 'foo', root: url, alias, url: alias})
+    })
+  })
+
+  it('deploys to the "alias" field from now.json on the master branch', () => {
+    const name = 'hello'
+    const alias = 'hello.world'
+    mockFiles({
+      'package.json': {name},
+      'now.json': {alias},
+      'rules.json': null
+    })
+
+    const root = 'hello-123.now.sh'
+    now.mockImplementation(() => Promise.resolve(root))
+    mockEnv({GITHUB_REF: 'refs/heads/master'})
+
+    return deploy().then(res => {
+      expect(now).toHaveBeenCalledTimes(2)
+      expect(now).toHaveBeenNthCalledWith(1)
+      expect(now).toHaveBeenNthCalledWith(2, ['alias', root, alias])
+      expect(res).toEqual({name, root, url: alias})
+    })
+  })
+
+  it('calls now() two times when there is a rules.json, not on master', () => {
+    const prodAlias = 'foo.now.sh'
+    mockFiles({
+      'package.json': {name: 'foo'},
+      'now.json': {alias: prodAlias},
+      // exists
+      'rules.json': {}
+    })
+
+    const url = 'foo-123.now.sh'
+    const alias = 'foo-bar.now.sh'
+    now.mockImplementation(() => Promise.resolve(url))
+    mockEnv({GITHUB_REF: 'refs/heads/bar'})
+
+    return deploy().then(res => {
+      expect(now).toHaveBeenCalledTimes(2)
+      expect(now).toHaveBeenNthCalledWith(1)
+      expect(now).toHaveBeenNthCalledWith(2, ['alias', url, alias])
+      expect(res).toEqual({name: 'foo', root: url, alias, url: alias})
+    })
+  })
+
+  it('calls now() three times when there is a rules.json, on master', () => {
+    const prodAlias = 'primer.style'
+    mockFiles({
+      'package.json': {name: 'primer-style'},
+      'now.json': {alias: prodAlias},
+      // exists
+      'rules.json': {}
+    })
+
+    const url = 'primer-style-123.now.sh'
+    const alias = 'primer-style.now.sh'
+    now.mockImplementation(() => Promise.resolve(url))
+    mockEnv({GITHUB_REF: 'refs/heads/master'})
+
+    return deploy().then(res => {
+      expect(now).toHaveBeenCalledTimes(3)
+      expect(now).toHaveBeenNthCalledWith(1)
+      expect(now).toHaveBeenNthCalledWith(2, ['alias', url, alias])
+      expect(now).toHaveBeenNthCalledWith(3, ['alias', alias, prodAlias, '-r', 'rules.json'])
+      expect(res).toEqual({name: 'primer-style', root: url, alias, url: prodAlias})
+    })
+  })
+
+  function mockEnv(env) {
+    restoreEnv = mockedEnv(env)
+  }
+
+  function mockFiles(files) {
+    readJSON.mockImplementation(path => {
+      if (path in files) {
+        return files[path]
+      }
+    })
+  }
+})

src/__tests__/get-alias.js

@@ -1,10 +1,7 @@
-const mockedEnv = require('mocked-env')
 const getAlias = require('../get-alias')
 
 describe('getAlias()', () => {
   it('works', () => {
-    const restore = mockedEnv({GITHUB_REF: 'refs/heads/add-foo'})
-    expect(getAlias('@primer/css')).toEqual('primer-css-add-foo.now.sh')
-    restore()
+    expect(getAlias('@primer/css', 'add-foo')).toEqual('primer-css-add-foo.now.sh')
   })
 })

src/__tests__/get-branch.js

@@ -7,4 +7,10 @@ describe('getBranch()', () => {
     expect(getBranch()).toEqual('foo')
     restore()
   })
+
+  it('returns an empty string if GITHUB_REF is unset', () => {
+    const restore = mockedEnv({GITHUB_REF: undefined})
+    expect(getBranch()).toEqual('')
+    restore()
+  })
 })

src/__tests__/now.js

@@ -0,0 +1,32 @@
+const execa = require('execa')
+const mockedEnv = require('mocked-env')
+const now = require('../now')
+
+jest.mock('execa')
+execa.mockImplementation(() => Promise.resolve({stderr: '', stdout: ''}))
+
+describe('now()', () => {
+  let restoreEnv = () => {}
+  afterEach(() => restoreEnv())
+
+  it('throws if process.env.NOW_TOKEN is falsy', () => {
+    mockEnv({NOW_TOKEN: ''})
+    expect(() => now()).toThrow()
+  })
+
+  it('calls `npx now --token=$NOW_TOKEN` with no additional args', () => {
+    mockEnv({NOW_TOKEN: 'xyz'})
+    now()
+    expect(execa).lastCalledWith('npx', ['now', '--token=xyz'], {stderr: 'inherit'})
+  })
+
+  it('calls with additional arguments passed as an array', () => {
+    mockEnv({NOW_TOKEN: 'abc'})
+    now(['foo', 'bar'])
+    expect(execa).lastCalledWith('npx', ['now', '--token=abc', 'foo', 'bar'], {stderr: 'inherit'})
+  })
+
+  function mockEnv(env) {
+    restoreEnv = mockedEnv(env)
+  }
+})

src/__tests__/read-json.js

@@ -0,0 +1,12 @@
+const readJSON = require('../read-json')
+
+describe('readJSON()', () => {
+  it('reads package.json from the cwd', () => {
+    const pkg = readJSON('package.json')
+    expect(pkg instanceof Object).toBe(true)
+  })
+
+  it('returns undefined for non-existent files', () => {
+    expect(readJSON('x.json')).toBe(undefined)
+  })
+})

src/deploy.js

@@ -1,26 +1,63 @@
 const {dirname} = require('path')
-const now = require('./now')
-const getAlias = require('./get-alias')
+const getBranch = require('./get-branch')
 const commitStatus = require('./commit-status')
+const getBranchAlias = require('./get-alias')
+const now = require('./now')
+const readJSON = require('./read-json')
+
+module.exports = function deploy() {
+  const nowJson = readJSON('now.json') || {}
+  const packageJson = readJSON('package.json') || {}
+  const rulesJson = readJSON('rules.json')
 
-module.exports = function deploy(args) {
-  const nowJson = require('./now-json')
-  const packageJson = require('./package-json')
   const name = nowJson.name || packageJson.name || dirname(process.cwd())
+  const branch = getBranch(name)
+
   console.log(`[deploy] deploying "${name}" with now...`)
-  return now(args)
+  return now()
     .then(url => {
-      console.log(`[deploy] deployed to: ${url}`)
-      return {name, root: url, url}
+      if (url) {
+        // console.log(`[deploy] deployed to: ${url}`)
+        return {
+          name,
+          root: url,
+          url
+        }
+      } else {
+        throw new Error(`Unable to get deployment URL from now: ${url}`)
+      }
     })
     .then(res => {
       const {url} = res
-      const alias = getAlias(name)
-      if (alias) {
-        res.url = alias
-        return now(['alias', ...args, url, alias])
-          .then(() => commitStatus(alias))
+      const prodAlias = nowJson.alias
+      if (branch === 'master' && !rulesJson) {
+        res.url = prodAlias
+        return now(['alias', url, prodAlias])
+          .then(() => commitStatus(prodAlias))
+          .then(() => res)
+      }
+      const branchAlias = getBranchAlias(name, branch)
+      if (branchAlias) {
+        res.url = res.alias = branchAlias
+        return now(['alias', url, branchAlias])
+          .then(() => commitStatus(branchAlias))
+          .then(() => {
+            if (branch === 'master' && rulesJson) {
+              const {alias} = res
+              if (!prodAlias) {
+                console.warn(`[deploy] no alias field in now.json!`)
+                return res
+              } else if (prodAlias === alias) {
+                console.warn(`[deploy] already aliased to production URL: ${alias}; skipping rules.json`)
+                return res
+              }
+              res.url = prodAlias
+              return now(['alias', alias, prodAlias, '-r', 'rules.json']).then(() => commitStatus(prodAlias))
+            }
+          })
           .then(() => res)
+      } else {
+        return res
       }
     })
 }

src/get-alias.js

@@ -1,9 +1,7 @@
-const getBranch = require('./get-branch')
 const slug = require('./slug')
 
-module.exports = function getAlias(name) {
+module.exports = function getAlias(name, branch) {
   const nameSlug = slug(name)
-  const branch = getBranch()
 
   if (branch === 'master') {
     return `${nameSlug}.now.sh`

src/now.js

@@ -5,5 +5,6 @@ module.exports = function now(args = []) {
   if (!NOW_TOKEN) {
     throw new Error(`The NOW_TOKEN env var is required`)
   }
-  return execa('npx', ['now', `--token=${NOW_TOKEN}`, ...args], {stderr: 'inherit'}).then(res => res.stdout)
+  const nowArgs = ['now', `--token=${NOW_TOKEN}`, ...args]
+  return execa('npx', nowArgs, {stderr: 'inherit'}).then(res => res.stdout)
 }

src/read-json.js

@@ -0,0 +1,7 @@
+const {resolve} = require('path')
+const {existsSync} = require('fs')
+
+module.exports = function readJSON(path) {
+  const resolved = resolve(process.cwd(), path)
+  return existsSync(resolved) ? require(resolved) : undefined
+}