feat: add reset module (#94)

* feat: add reset module

* reset with people

* add people to data.json

Author: bahmutov

README.md

@@ -96,6 +96,19 @@ $ http POST :3000/merge people:=[]
 // { todos: [...], people: [] }
 ```
 
+## Init reset
+
+If using this middleware from your server, you can clear some resources on startup
+
+```js
+const initJsonServerReset = require('json-server-reset/src/init-reset')
+
+const router = jsonServer.router(dataFilename)
+// list of REST resources to clear on startup
+const clear = ['todos']
+server.use(initJsonServerReset({ db: router.db, clear }))
+```
+
 ### Debugging
 
 Run this module with environment variable

cypress/fixtures/data.json

@@ -1,18 +1,4 @@
 {
-  "todos": [
-    {
-      "id": 1,
-      "title": "first"
-    },
-    {
-      "id": 2,
-      "title": "second"
-    }
-  ],
-  "people": [
-    {
-      "name": "A person 5155",
-      "id": 1
-    }
-  ]
-}
+  "todos": [],
+  "people": []
+}

cypress/fixtures/example-server.js

@@ -1,5 +1,5 @@
 const jsonServer = require('json-server')
-const reset = require('../../src')
+const initJsonServerReset = require('../../src/init-reset')
 const merge = require('../../src/merge')
 const path = require('path')
 const dataFilename = path.join(__dirname, 'data.json')
@@ -16,7 +16,10 @@ server.use(
     readOnly: false,
   }),
 )
-server.use(reset)
+
+// list of REST resources to clear on startup
+const clear = ['todos', 'people']
+server.use(initJsonServerReset({ db: router.db, clear }))
 server.use(merge)
 server.db = router.db
 server.use(router)

package.json

@@ -41,7 +41,7 @@
     "cy:open:4000": "cypress open --config baseUrl=http://localhost:4000",
     "start": "json-server cypress/fixtures/data.json --middlewares ./src/index.js --middlewares ./src/merge",
     "start:server": "node ./cypress/fixtures/example-server",
-    "watch:server": "node --watch ./cypress/fixtures/example-server",
+    "watch:server": "DEBUG=json-server-reset node --watch ./cypress/fixtures/example-server",
     "e2e": "start-server-and-test 3000 cy:run",
     "dev": "start-server-and-test 3000 cy:open",
     "dev2": "start-test start:server 4000 cy:open:4000",

src/index.js

@@ -1,54 +1,3 @@
-const debug = require('debug')('json-server-reset')
-const { isEmptyObject, arraysAreDifferent } = require('./utils')
-
-// adds /reset route to your json-server
-// to use execute POST /reset <JSON state>
-// for example using httpie
-//   http localhost:3000/reset todos=[]
-function jsonServerReset(req, res, next) {
-  if (req.method === 'POST' && req.path === '/reset') {
-    console.log('resetting database')
-    // TODO it would be nice to restore not with an empty object
-    // but with the initial database
-    const data = req.body || {}
-    if (isEmptyObject(data)) {
-      console.error('Resetting with an empty object not allowed')
-      return res.sendStatus(400)
-    }
-    if (Array.isArray(data)) {
-      console.error('Resetting with an array not allowed')
-      return res.sendStatus(400)
-    }
-
-    debug('new data %o', data)
-
-    const currentKeys = Object.keys(req.app.db.getState()).sort()
-    const newKeys = Object.keys(data).sort()
-    debug('existing REST keys %o', currentKeys)
-    debug('new REST keys %o', newKeys)
-    if (arraysAreDifferent(currentKeys, newKeys)) {
-      console.warn(
-        '⚠️ Resetting REST endpoints %s with %s',
-        JSON.stringify(currentKeys),
-        JSON.stringify(newKeys),
-      )
-    }
-
-    req.app.db.setState(data)
-    // and immediately write the database file
-    const p = req.app.db.write()
-    if (p && p.then) {
-      return p.then(() => {
-        debug('have async written updated data to disk')
-        return res.sendStatus(200)
-      })
-    } else {
-      debug('have sync written updated data to disk')
-      return res.sendStatus(200)
-    }
-  }
-  // not a POST /reset
-  next()
-}
+const jsonServerReset = require('./reset')
 
 module.exports = jsonServerReset

src/init-reset.js

@@ -0,0 +1,27 @@
+const debug = require('debug')('json-server-reset')
+const jsonServerReset = require('./reset')
+
+function initJsonServerReset(options = {}) {
+  debug('init options keys %o', Object.keys(options))
+  if (options.db && options.clear) {
+    const db = options.db
+    debug('resources to clear', options.clear)
+    const state = db.getState()
+    let changedState = false
+    Object.keys(state).forEach((key) => {
+      if (options.clear.includes(key)) {
+        debug('clearing %s', key)
+        state[key] = []
+        changedState = true
+      }
+    })
+    if (changedState) {
+      debug('saving updated DB')
+      db.setState(state)
+      db.write()
+    }
+  }
+  return jsonServerReset
+}
+
+module.exports = initJsonServerReset

src/reset.js

@@ -0,0 +1,55 @@
+const debug = require('debug')('json-server-reset')
+const { isEmptyObject, arraysAreDifferent } = require('./utils')
+
+/**
+ * adds the `/reset` route to your json-server
+ * @example http localhost:3000/reset todos=[]
+ * @see https://github.com/bahmutov/json-server-reset
+ */
+function jsonServerReset(req, res, next) {
+  if (req.method === 'POST' && req.path === '/reset') {
+    console.log('resetting database')
+    // TODO it would be nice to restore not with an empty object
+    // but with the initial database
+    const data = req.body || {}
+    if (isEmptyObject(data)) {
+      console.error('Resetting with an empty object not allowed')
+      return res.sendStatus(400)
+    }
+    if (Array.isArray(data)) {
+      console.error('Resetting with an array not allowed')
+      return res.sendStatus(400)
+    }
+
+    debug('new data %o', data)
+
+    const currentKeys = Object.keys(req.app.db.getState()).sort()
+    const newKeys = Object.keys(data).sort()
+    debug('existing REST keys %o', currentKeys)
+    debug('new REST keys %o', newKeys)
+    if (arraysAreDifferent(currentKeys, newKeys)) {
+      console.warn(
+        '⚠️ Resetting REST endpoints %s with %s',
+        JSON.stringify(currentKeys),
+        JSON.stringify(newKeys),
+      )
+    }
+
+    req.app.db.setState(data)
+    // and immediately write the database file
+    const p = req.app.db.write()
+    if (p && p.then) {
+      return p.then(() => {
+        debug('have async written updated data to disk')
+        return res.sendStatus(200)
+      })
+    } else {
+      debug('have sync written updated data to disk')
+      return res.sendStatus(200)
+    }
+  }
+  // not a POST /reset
+  next()
+}
+
+module.exports = jsonServerReset