IndexedDB handler for CRUD operations

idbAPI.js

/*
  Minified: ~1Kb
  Author: Mariano Paulin - marianopaulin.com
  Description: IndexedDB(idb) javascript promise-based handler to perform simple CRUD operations with key-value data
  Tested: Most recent versions of popular browsers, compatible with service workers
  Reference: https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB
  Test, examples and docs: (at the bottom)
  
*/

//SCRIPT

function idbAPI(dbname,version,upgradeFn){// IndexedDB API for CRUD operations: Create(put), Read(get), Update(update), and Delete(delete)
  var idb = indexedDB || mozIndexedDB || webkitIndexedDB || msIndexedDB,
      dbPromise = new Promise((resolve,reject)=>{
        var dbp = idb.open(dbname,version);
        dbp.onupgradeneeded=(event)=>upgradeFn(dbp.result)
        dbp.onsuccess = (event)=>resolve(dbp.result);
        dbp.onerror = (event)=>reject(event.target);
    }),
    handleRequest = (request)=>{
      return new Promise((resolve,reject)=>{
        request.onerror = (event)=>{reject(event)};
        request.onsuccess = (event)=>{resolve(event.target.result)}
      })
    },
    check=(data)=>{
      return new Promise((resolve,reject)=>{
        if(data instanceof Object && data.key!==undefined)return resolve();
        reject('<data> must be or contain an object like {key:string,..}')
      })
    },
    validateInputData = (data)=>{
      if(data instanceof Array){
        return Promise.all(data.map((dt)=>{return check(dt)}))
      }
      return check(data)
    },
    getDBPromise=()=>{
      return dbPromise
    },
    isArray=(data)=>{
      return data instanceof Array;
    },
    getObjectStore=(db,storeName,readwrite)=>{
      return db.transaction([storeName],(readwrite)?"readwrite":undefined).objectStore(storeName)
    },
    /* METHODS */
    get = (storeName,key)=>{//get key or [keys]
      return dbPromise.then(db=>{
        var objectStore =  getObjectStore(db,storeName)
        if(isArray(key)){//multiple get operations
          return Promise.all(key.map((key)=>{return handleRequest(objectStore.get(key))}))
        }
        return handleRequest(objectStore.get(key))
      })
    },
    put = (storeName,data)=>{//write or replace the current value for a single or multiple keys
      //if <data> is {key:string,..}
      //if <data> is [{key:string,..},{key:string,..}]
      return validateInputData(data)
      .then(getDBPromise)
      .then(db=>{
        var objectStore = getObjectStore(db,storeName,1)
        if(isArray(data))return Promise.all(data.map((data)=>{return handleRequest(objectStore.put(data))}))
        return handleRequest(objectStore.put(data));
      })
    },
    update = (storeName,data)=>{//update the current value for the key or add it
      //<data> is {key:string,..}
      return validateInputData(data)
      .then(getDBPromise)
      .then(db=>{
        var objectStore = getObjectStore(db,storeName,1);
        handleRequest(objectStore.get(data.key)).then(dbdata=>{
          if(dbdata){//if already exists, merge properties
            Object.assign(dbdata,data)
          }
          return handleRequest(objectStore.put(dbdata));
        })
      })
    },
    deletefn = (storeName,key)=>{//deletes the value of a given key or [keys]
      //<key> is string
      //<key> is [string,..]
      return getDBPromise()
      .then(db=>{
        var objectStore = getObjectStore(db,storeName,1)
        if(key instanceof Array){//multiple get operations
          return Promise.all(key.map((key)=>{return handleRequest(objectStore.delete(key))}))
        }
        return handleRequest(objectStore.delete(key));
      })
    };
  return {
    promise:dbPromise,
    get:get,
    put:put,
    update:update,
    delete:deletefn
  }
}


//USAGE AND TEST///////////////////

function upgradeFn(db){//
  if (!db.objectStoreNames.contains('myStore')) {
		  db.createObjectStore('myStore',{keyPath:"key"})
		}
}
var midb = new idbAPI('dataBaseName',1,upgradeFn)
midb.put('myStore',[{key:'key1',a:8},{key:'key2',a:9}])//put multiple
.then(()=>{
  console.log('multiple keys added (key1, key2)')
  return midb.put('myStore',{key:'key3',a:10})//put simple
})
.then((d)=>{
  console.log('single key added (key3)')
  return midb.update('myStore',{key:'key3',a:11,b:true})
})
.then((d)=>{
  console.log('key3 updated')
  return midb.get('myStore','key2')//get single key
})
.then(res=>{
  console.log('key2 value:',res)
  return midb.delete('myStore','key2')//delete single key
})
.then(()=>{
  console.log('key2 was deleted')
  return midb.get('myStore',['key1','key3'])//get multiple keys
})
.then(res=>{
    console.log('multiget values (key1, key3)',res)
})