Updated rxjs version and fixed the type error issue

package.json

@@ -39,7 +39,7 @@
   },
   "peerDependencies": {
     "reflect-metadata": ">=0.1.3",
-    "rxjs": ">=5.2.0"
+    "rxjs": ">=6"
   },
   "devDependencies": {
     "@angular/animations": "^4.4.3",
@@ -71,7 +71,8 @@
     "karma-webpack": "^2.0.3",
     "reflect-metadata": "^0.1.3",
     "rimraf": "^2.6.2",
-    "rxjs": "5.4.2",
+    "rxjs": "6",
+    "rxjs-compat": "6",
     "sourcemap-istanbul-instrumenter-loader": "^0.2.0",
     "ts-loader": "^2.3.7",
     "tslint": "^5.7.0",

src/models/json-api.model.ts

@@ -1,6 +1,6 @@
 import find from 'lodash-es/find';
 import includes from 'lodash-es/includes';
-import { Observable } from 'rxjs/Observable';
+import { Observable } from 'rxjs';
 import { JsonApiDatastore, ModelType } from '../services/json-api-datastore.service';
 import { ModelConfig } from '../interfaces/model-config.interface';
 import * as _ from 'lodash';

src/services/json-api-datastore.service.ts

@@ -1,12 +1,9 @@
 import { Injectable } from '@angular/core';
 import { HttpClient, HttpHeaders, HttpResponse, HttpErrorResponse } from '@angular/common/http';
 import find from 'lodash-es/find';
-import { Observable } from 'rxjs/Observable';
+import { map, catchError } from 'rxjs/operators';
+import { throwError, of, Observable } from 'rxjs';
 import { ErrorObservable } from 'rxjs/observable/ErrorObservable';
-import 'rxjs/add/operator/map';
-import 'rxjs/add/operator/catch';
-import 'rxjs/add/observable/throw';
-import 'rxjs/add/observable/of';
 import { JsonApiModel } from '../models/json-api.model';
 import { ErrorResponse } from '../models/error-response.model';
 import { JsonApiQueryData } from '../models/json-api-query-data';
@@ -32,9 +29,8 @@ export class JsonApiDatastore {
     if (this.datastoreConfig.overrides
     && this.datastoreConfig.overrides.getDirtyAttributes) {
       return this.datastoreConfig.overrides.getDirtyAttributes;
-    } else {
-      return JsonApiDatastore.getDirtyAttributes;
     }
+    return JsonApiDatastore.getDirtyAttributes;
   }
 
   protected config: DatastoreConfig;
@@ -51,8 +47,10 @@ export class JsonApiDatastore {
     const requestHeaders: HttpHeaders = this.buildHeaders(headers);
     const url: string = this.buildUrl(modelType, params, undefined, customUrl);
     return this.http.get(url, { headers: requestHeaders })
-      .map((res: any) => this.extractQueryData(res, modelType))
-      .catch((res: any) => this.handleError(res));
+      .pipe(
+        map((res: any) => this.extractQueryData(res, modelType)),
+        catchError((res: any) => this.handleError(res))
+      );
   }
 
   findAll<T extends JsonApiModel>(
@@ -65,8 +63,10 @@ export class JsonApiDatastore {
     const url: string = this.buildUrl(modelType, params, undefined, customUrl);
 
     return this.http.get(url, { headers: requestHeaders })
-      .map((res: any) => this.extractQueryData(res, modelType, true))
-      .catch((res: any) => this.handleError(res));
+      .pipe(
+        map((res: any) => this.extractQueryData(res, modelType, true)),
+        catchError((res: any) => this.handleError(res))
+      );
   }
 
   findRecord<T extends JsonApiModel>(
@@ -80,8 +80,10 @@ export class JsonApiDatastore {
     const url: string = this.buildUrl(modelType, params, id, customUrl);
 
     return this.http.get(url, { headers: requestHeaders, observe: 'response' })
-      .map((res) => this.extractRecordData(res, modelType))
-      .catch((res: any) => this.handleError(res));
+      .pipe(
+        map((res) => this.extractRecordData(res, modelType)),
+        catchError((res: any) => this.handleError(res))
+      );
   }
 
   createRecord<T extends JsonApiModel>(modelType: ModelType<T>, data?: any): T {
@@ -135,16 +137,17 @@ export class JsonApiDatastore {
     }
 
     return httpCall
-      .map((res) => [200, 201].indexOf(res.status) !== -1 ? this.extractRecordData(res, modelType, model) : model)
-      .catch((res) => {
-        if (res == null) {
-          return Observable.of(model);
-        }
-
-        return this.handleError(res);
-      })
-      .map((res) => this.resetMetadataAttributes(res, attributesMetadata, modelType))
-      .map((res) => this.updateRelationships(res, relationships));
+      .pipe(
+        map((res) => [200, 201].indexOf(res.status) !== -1 ? this.extractRecordData(res, modelType, model) : model),
+        catchError((res) => {
+          if (res == null) {
+            return of(model);
+          }
+          return this.handleError(res);
+        }),
+        map((res) => this.resetMetadataAttributes(res, attributesMetadata, modelType)),
+        map((res) => this.updateRelationships(res, relationships))
+      );
   }
 
 
@@ -158,7 +161,10 @@ export class JsonApiDatastore {
     const requestHeaders: HttpHeaders = this.buildHeaders(headers);
     const url: string = this.buildUrl(modelType, null, id, customUrl);
 
-    return this.http.delete(url, { headers: requestHeaders }).catch((res: HttpErrorResponse) => this.handleError(res));
+    return this.http.delete(url, { headers: requestHeaders })
+      .pipe(
+        catchError((res: HttpErrorResponse) => this.handleError(res))
+      );
   }
 
   peekRecord<T extends JsonApiModel>(modelType: ModelType<T>, id: string): T | null {
@@ -316,7 +322,7 @@ export class JsonApiDatastore {
     return deserializedModel;
   }
 
-  protected handleError(error: any): ErrorObservable {
+  protected handleError(error: any): ErrorObservable<any> {
 
     if (
       error instanceof HttpErrorResponse &&
@@ -326,11 +332,11 @@ export class JsonApiDatastore {
     ) {
       const errors: ErrorResponse = new ErrorResponse(error.error.errors);
       console.error(error, errors);
-      return Observable.throw(errors);
+      return throwError(errors);
     }
 
     console.error(error);
-    return Observable.throw(error);
+    return throwError(error);
   }
 
   protected parseMeta(body: any, modelType: ModelType<JsonApiModel>): any {