diff --git a/src/enforcer.ts b/src/enforcer.ts
index 1ad7db3..91ad530 100644
--- a/src/enforcer.ts
+++ b/src/enforcer.ts
@@ -132,19 +132,15 @@ export class Enforcer {
     this.model = m;
     this.model.printModel();
     this.fm = FunctionMap.loadFunctionMap();
-
-    this.initialize();
-
-    if (this.adapter && (this.adapter instanceof FileAdapter)) {
-      // error intentionally ignored
-      this.loadPolicy();
-    }
   }
 
-  private initialize(): void {
+  public async initialize(): Promise<void> {
     this.enabled = true;
     this.autoSave = true;
     this.autoBuildRoleLinks = true;
+    if (this.adapter) {
+      await this.loadPolicy();
+    }
   }
 
   /**
@@ -222,7 +218,7 @@ export class Enforcer {
    */
   public setWatcher(watcher: Watcher): void {
     this.watcher = watcher;
-    watcher.setUpdateCallback(() => this.loadPolicy());
+    watcher.setUpdateCallback(async () => await this.loadPolicy());
   }
 
   /**
@@ -253,9 +249,9 @@ export class Enforcer {
   /**
    * loadPolicy reloads the policy from file/database.
    */
-  public loadPolicy(): void {
+  public async loadPolicy(): Promise<void> {
     this.model.clearPolicy();
-    this.adapter.loadPolicy(this.model);
+    await this.adapter.loadPolicy(this.model);
 
     this.model.printPolicy();
     if (this.autoBuildRoleLinks) {
@@ -300,11 +296,12 @@ export class Enforcer {
    * savePolicy saves the current policy (usually after changed with
    * Casbin API) back to file/database.
    */
-  public savePolicy(): boolean {
+  public async savePolicy(): Promise<boolean> {
     if (this.isFiltered()) {
       throw new Error('cannot save a filtered policy');
     }
-    if (!this.adapter.savePolicy(this.model)) {
+    const flag = await this.adapter.savePolicy(this.model);
+    if (!flag) {
       return false;
     }
     if (this.watcher) {
@@ -510,7 +507,7 @@ export class Enforcer {
   /**
    * addPolicy adds a rule to the current policy.
    */
-  public addPolicy(sec: string | any[], key?: string, rule?: string[]): boolean {
+  public async addPolicy(sec: string | any[], key?: string, rule?: string[]): Promise<boolean> {
     if (typeof sec === 'string' && key && rule) {
       const ruleAdded = this.model.addPolicy(sec, key, rule);
       if (!ruleAdded) {
@@ -518,7 +515,7 @@ export class Enforcer {
       }
 
       if (this.adapter !== null && this.autoSave) {
-        this.adapter.addPolicy(sec, key, rule);
+        await this.adapter.addPolicy(sec, key, rule);
         if (this.watcher !== null) {
           // error intentionally ignored
           this.watcher.update();
@@ -527,7 +524,7 @@ export class Enforcer {
 
       return ruleAdded;
     } else if (sec instanceof Array) {
-      return this.addNamedPolicy('p', sec);
+      return await this.addNamedPolicy('p', sec);
     } else {
       return false;
     }
@@ -536,7 +533,7 @@ export class Enforcer {
   /**
    * removePolicy removes a rule from the current policy.
    */
-  public removePolicy(sec: string | any[], key?: string, rule?: string[]): boolean {
+  public async removePolicy(sec: string | any[], key?: string, rule?: string[]): Promise<boolean> {
     if (typeof sec === 'string' && key && rule) {
       const ruleRemoved = this.model.removePolicy(sec, key, rule);
       if (!ruleRemoved) {
@@ -544,7 +541,7 @@ export class Enforcer {
       }
 
       if (this.adapter !== null && this.autoSave) {
-        this.adapter.removePolicy(sec, key, rule);
+        await this.adapter.removePolicy(sec, key, rule);
         if (this.watcher !== null) {
           // error intentionally ignored
           this.watcher.update();
@@ -553,7 +550,7 @@ export class Enforcer {
 
       return ruleRemoved;
     } else if (sec instanceof Array) {
-      return this.removeNamedPolicy('p', sec);
+      return await this.removeNamedPolicy('p', sec);
     } else {
       return false;
     }
@@ -562,7 +559,7 @@ export class Enforcer {
   /**
    * removeFilteredPolicy removes rules based on field filters from the current policy.
    */
-  public removeFilteredPolicy(sec: string | number, key: string | string[], fieldIndex?: number, fieldValues?: string[]): boolean {
+  public async removeFilteredPolicy(sec: string | number, key: string | string[], fieldIndex?: number, fieldValues?: string[]): Promise<boolean> {
     if (typeof sec === 'string' && typeof key === 'string' && fieldIndex && fieldValues instanceof Array) {
       const ruleRemoved = this.model.removeFilteredPolicy(sec, key, fieldIndex, ...fieldValues);
       if (!ruleRemoved) {
@@ -570,7 +567,7 @@ export class Enforcer {
       }
 
       if (this.adapter !== null && this.autoSave) {
-        this.adapter.removeFilteredPolicy(sec, key, fieldIndex, ...fieldValues);
+        await this.adapter.removeFilteredPolicy(sec, key, fieldIndex, ...fieldValues);
         if (this.watcher !== null) {
           // error intentionally ignored
           this.watcher.update();
@@ -579,7 +576,7 @@ export class Enforcer {
 
       return ruleRemoved;
     } else if (typeof sec === 'number' && key instanceof Array) {
-      return this.removeFilteredNamedPolicy('p', sec, key);
+      return await this.removeFilteredNamedPolicy('p', sec, key);
     } else {
       return false;
     }
@@ -806,12 +803,12 @@ export class Enforcer {
    * @param params the "p" policy rule.
    * @return succeeds or not.
    */
-  public addNamedPolicy(ptype: string, params: any[]): boolean {
+  public async addNamedPolicy(ptype: string, params: any[]): Promise<boolean> {
     let ruleAdded = false;
     if (params.length === 1 && params[0] instanceof Array) {
-      ruleAdded = this.addPolicy('p', ptype, params[0]);
+      ruleAdded = await this.addPolicy('p', ptype, params[0]);
     } else {
-      ruleAdded = this.addPolicy('p', ptype, params);
+      ruleAdded = await this.addPolicy('p', ptype, params);
     }
 
     return ruleAdded;
@@ -824,12 +821,12 @@ export class Enforcer {
    * @param params the "p" policy rule.
    * @return succeeds or not.
    */
-  public removeNamedPolicy(ptype: string, params: any[]): boolean {
+  public async removeNamedPolicy(ptype: string, params: any[]): Promise<boolean> {
     let ruleRemoved = false;
     if (params.length === 1 && params[0] instanceof Array) {
-      ruleRemoved = this.removePolicy('p', ptype, params[0]);
+      ruleRemoved = await this.removePolicy('p', ptype, params[0]);
     } else {
-      ruleRemoved = this.removePolicy('p', ptype, params);
+      ruleRemoved = await this.removePolicy('p', ptype, params);
     }
 
     return ruleRemoved;
@@ -844,8 +841,8 @@ export class Enforcer {
    *                    means not to match this field.
    * @return succeeds or not.
    */
-  public removeFilteredNamedPolicy(ptype: string, fieldIndex: number, fieldValues: string[]): boolean {
-    return this.removeFilteredPolicy('p', ptype, fieldIndex, fieldValues);
+  public async removeFilteredNamedPolicy(ptype: string, fieldIndex: number, fieldValues: string[]): Promise<boolean> {
+    return await this.removeFilteredPolicy('p', ptype, fieldIndex, fieldValues);
   }
 
   /**
@@ -880,8 +877,8 @@ export class Enforcer {
    * @param params the "g" policy rule, ptype "g" is implicitly used.
    * @return succeeds or not.
    */
-  public addGroupingPolicy(...params: any[]): boolean {
-    return this.addNamedGroupingPolicy('g', params);
+  public async addGroupingPolicy(...params: any[]): Promise<boolean> {
+    return await this.addNamedGroupingPolicy('g', params);
   }
 
   /**
@@ -893,12 +890,12 @@ export class Enforcer {
    * @param params the "g" policy rule.
    * @return succeeds or not.
    */
-  public addNamedGroupingPolicy(ptype: string, ...params: any[]): boolean {
+  public async addNamedGroupingPolicy(ptype: string, ...params: any[]): Promise<boolean> {
     let ruleadded = false;
     if (params.length === 1 && params[0] instanceof Array) {
-      ruleadded = this.addPolicy('g', ptype, params[0]);
+      ruleadded = await this.addPolicy('g', ptype, params[0]);
     } else {
-      ruleadded = this.addPolicy('g', ptype, params);
+      ruleadded = await this.addPolicy('g', ptype, params);
     }
 
     if (this.autoBuildRoleLinks) {
@@ -914,8 +911,8 @@ export class Enforcer {
    * @param params the "g" policy rule, ptype "g" is implicitly used.
    * @return succeeds or not.
    */
-  public removeGroupingPolicy(...params: any[]): boolean {
-    return this.removeNamedGroupingPolicy('g', params);
+  public async removeGroupingPolicy(...params: any[]): Promise<boolean> {
+    return await this.removeNamedGroupingPolicy('g', params);
   }
 
   /**
@@ -926,8 +923,8 @@ export class Enforcer {
    *                    means not to match this field.
    * @return succeeds or not.
    */
-  public removeFilteredGroupingPolicy(fieldIndex: number, ...fieldValues: string[]): boolean {
-    return this.removeFilteredNamedGroupingPolicy('g', fieldIndex, ...fieldValues);
+  public async removeFilteredGroupingPolicy(fieldIndex: number, ...fieldValues: string[]): Promise<boolean> {
+    return await this.removeFilteredNamedGroupingPolicy('g', fieldIndex, ...fieldValues);
   }
 
   /**
@@ -937,12 +934,12 @@ export class Enforcer {
    * @param params the "g" policy rule.
    * @return succeeds or not.
    */
-  public removeNamedGroupingPolicy(ptype: string, ...params: any[]): boolean {
+  public async removeNamedGroupingPolicy(ptype: string, ...params: any[]): Promise<boolean> {
     let ruleRemoved = false;
     if (params.length === 1 && params[0] instanceof Array) {
-      ruleRemoved = this.removePolicy('g', ptype, params[0]);
+      ruleRemoved = await this.removePolicy('g', ptype, params[0]);
     } else {
-      ruleRemoved = this.removePolicy('g', ptype, params);
+      ruleRemoved = await this.removePolicy('g', ptype, params);
     }
 
     if (this.autoBuildRoleLinks) {
@@ -960,8 +957,8 @@ export class Enforcer {
    *                    means not to match this field.
    * @return succeeds or not.
    */
-  public removeFilteredNamedGroupingPolicy(ptype: string, fieldIndex: number, ...fieldValues: string[]): boolean {
-    const ruleRemoved = this.removeFilteredPolicy('g', ptype, fieldIndex, fieldValues);
+  public async removeFilteredNamedGroupingPolicy(ptype: string, fieldIndex: number, ...fieldValues: string[]): Promise<boolean> {
+    const ruleRemoved = await this.removeFilteredPolicy('g', ptype, fieldIndex, fieldValues);
     if (this.autoBuildRoleLinks) {
       this.buildRoleLinks();
     }
@@ -1032,8 +1029,8 @@ export class Enforcer {
    * @param role the role.
    * @return succeeds or not.
    */
-  public addRoleForUser(user: string, role: string): boolean {
-    return this.addGroupingPolicy(user, role);
+  public async addRoleForUser(user: string, role: string): Promise<boolean> {
+    return await this.addGroupingPolicy(user, role);
   }
 
   /**
@@ -1044,8 +1041,8 @@ export class Enforcer {
    * @param role the role.
    * @return succeeds or not.
    */
-  public deleteRoleForUser(user: string, role: string): boolean {
-    return this.removeGroupingPolicy(user, role);
+  public async deleteRoleForUser(user: string, role: string): Promise<boolean> {
+    return await this.removeGroupingPolicy(user, role);
   }
 
   /**
@@ -1055,8 +1052,8 @@ export class Enforcer {
    * @param user the user.
    * @return succeeds or not.
    */
-  public deleteRolesForUser(user: string): boolean {
-    return this.removeFilteredGroupingPolicy(0, user);
+  public async deleteRolesForUser(user: string): Promise<boolean> {
+    return await this.removeFilteredGroupingPolicy(0, user);
   }
 
   /**
@@ -1066,8 +1063,8 @@ export class Enforcer {
    * @param user the user.
    * @return succeeds or not.
    */
-  public deleteUser(user: string): boolean {
-    return this.removeFilteredGroupingPolicy(0, user);
+  public async deleteUser(user: string): Promise<boolean> {
+    return await this.removeFilteredGroupingPolicy(0, user);
   }
 
   /**
@@ -1075,9 +1072,9 @@ export class Enforcer {
    *
    * @param role the role.
    */
-  public deleteRole(role: string) {
-    this.removeFilteredGroupingPolicy(1, role);
-    this.removeFilteredPolicy(0, role);
+  public async deleteRole(role: string): Promise<void> {
+    await this.removeFilteredGroupingPolicy(1, role);
+    await this.removeFilteredPolicy(0, role);
   }
 
   /**
@@ -1087,8 +1084,8 @@ export class Enforcer {
    * @param permission the permission, usually be (obj, act). It is actually the rule without the subject.
    * @return succeeds or not.
    */
-  public deletePermission(...permission: string[]): boolean {
-    return this.removeFilteredPolicy(1, permission);
+  public async deletePermission(...permission: string[]): Promise<boolean> {
+    return await this.removeFilteredPolicy(1, permission);
   }
 
   /**
@@ -1099,9 +1096,9 @@ export class Enforcer {
    * @param permission the permission, usually be (obj, act). It is actually the rule without the subject.
    * @return succeeds or not.
    */
-  public addPermissionForUser(user: string, ...permission: string[]): boolean {
+  public async addPermissionForUser(user: string, ...permission: string[]): Promise<boolean> {
     permission.unshift(user);
-    return this.addPolicy(permission);
+    return await this.addPolicy(permission);
   }
 
   /**
@@ -1112,9 +1109,9 @@ export class Enforcer {
    * @param permission the permission, usually be (obj, act). It is actually the rule without the subject.
    * @return succeeds or not.
    */
-  public deletePermissionForUser(user: string, ...permission: string[]): boolean {
+  public async deletePermissionForUser(user: string, ...permission: string[]): Promise<boolean> {
     permission.unshift(user);
-    return this.removePolicy(permission);
+    return await this.removePolicy(permission);
   }
 
   /**
@@ -1124,8 +1121,8 @@ export class Enforcer {
    * @param user the user.
    * @return succeeds or not.
    */
-  public deletePermissionsForUser(user: string): boolean {
-    return this.removeFilteredPolicy(0, user);
+  public async deletePermissionsForUser(user: string): Promise<boolean> {
+    return await this.removeFilteredPolicy(0, user);
   }
 
   /**
diff --git a/src/persist/adapter.ts b/src/persist/adapter.ts
index f5de9ea..7326d9c 100644
--- a/src/persist/adapter.ts
+++ b/src/persist/adapter.ts
@@ -15,14 +15,14 @@
 import { Model } from '../model';
 
 export interface Adapter {
-  loadPolicy(model: Model): void;
+  loadPolicy(model: Model): Promise<void>;
 
-  savePolicy(model: Model): void;
+  savePolicy(model: Model): Promise<boolean>;
 
-  addPolicy(sec: string, ptype: string, rule: string[]): void;
+  addPolicy(sec: string, ptype: string, rule: string[]): Promise<void>;
 
-  removePolicy(sec: string, ptype: string, rule: string[]): void;
+  removePolicy(sec: string, ptype: string, rule: string[]): Promise<void>;
 
   removeFilteredPolicy(sec: string, ptype: string, fieldIndex: number, ...fieldValues: string[]
-  ): void;
+  ): Promise<void>;
 }
diff --git a/src/persist/defaultFilteredAdapter.ts b/src/persist/defaultFilteredAdapter.ts
index 6da3783..0f5e0e1 100644
--- a/src/persist/defaultFilteredAdapter.ts
+++ b/src/persist/defaultFilteredAdapter.ts
@@ -3,7 +3,7 @@ import { Model } from '../model';
 import { FileAdapter } from './fileAdapter';
 import { Adapter } from './adapter';
 import { Helper } from './helper';
-import { readFileSync } from 'fs';
+import { readFile } from '../util';
 
 export class Filter {
   public g: string[] = [];
@@ -20,14 +20,14 @@ export class DefaultFilteredAdapter extends FileAdapter
   }
 
   // loadPolicy loads all policy rules from the storage.
-  public loadPolicy(model: Model): void {
+  public async loadPolicy(model: Model): Promise<void> {
     this.filtered = false;
-    super.loadPolicy(model);
+    await super.loadPolicy(model);
   }
 
-  public loadFilteredPolicy(model: Model, filter: Filter): void {
+  public async loadFilteredPolicy(model: Model, filter: Filter): Promise<void> {
     if (!filter) {
-      this.loadPolicy(model);
+      await this.loadPolicy(model);
       return;
     }
 
@@ -35,15 +35,15 @@ export class DefaultFilteredAdapter extends FileAdapter
       throw new Error('invalid file path, file path cannot be empty');
     }
 
-    this.loadFilteredPolicyFile(model, filter, Helper.loadPolicyLine);
+    await this.loadFilteredPolicyFile(model, filter, Helper.loadPolicyLine);
     this.filtered = true;
   }
 
-  private loadFilteredPolicyFile(model: Model, filter: Filter, handler: (line: string, model: Model) => void
-  ) {
-    const bodyBuf = readFileSync(this.filePath);
+  private async loadFilteredPolicyFile(model: Model, filter: Filter, handler: (line: string, model: Model) => void
+  ): Promise<void> {
+    const bodyBuf = await readFile(this.filePath);
     const lines = bodyBuf.toString().split('\n');
-    lines.forEach((n, index) => {
+    lines.forEach((n: string, index: number) => {
       const line = n.trim();
       if (!line || DefaultFilteredAdapter.filterLine(line, filter)) {
         return;
@@ -56,11 +56,12 @@ export class DefaultFilteredAdapter extends FileAdapter
     return this.filtered;
   }
 
-  public savePolicy(model: Model): void {
+  public async savePolicy(model: Model): Promise<boolean> {
     if (this.filtered) {
       throw new Error('cannot save a filtered policy');
     }
-    super.savePolicy(model);
+    await super.savePolicy(model);
+    return true;
   }
 
   private static filterLine(line: string, filter: Filter): boolean {
diff --git a/src/persist/fileAdapter.ts b/src/persist/fileAdapter.ts
index aa46938..0427a5a 100644
--- a/src/persist/fileAdapter.ts
+++ b/src/persist/fileAdapter.ts
@@ -1,8 +1,7 @@
 import { Adapter } from './adapter';
 import { Model } from '../model';
 import { Helper } from './helper';
-import { readFileSync, writeFileSync } from 'fs';
-import { arrayToString } from '../util';
+import { readFile, writeFile, arrayToString } from '../util';
 
 /**
  * FileAdapter is the file adapter for Casbin.
@@ -19,18 +18,18 @@ export class FileAdapter implements Adapter {
     this.filePath = filePath;
   }
 
-  public loadPolicy(model: Model): void {
+  public async loadPolicy(model: Model): Promise<void> {
     if (!this.filePath) {
       // throw new Error('invalid file path, file path cannot be empty');
       return;
     }
-    this.loadPolicyFile(model, Helper.loadPolicyLine);
+    await this.loadPolicyFile(model, Helper.loadPolicyLine);
   }
 
-  private loadPolicyFile(model: Model, handler: (line: string, model: Model) => void) {
-    const bodyBuf = readFileSync(this.filePath);
+  private async loadPolicyFile(model: Model, handler: (line: string, model: Model) => void): Promise<void> {
+    const bodyBuf = await readFile(this.filePath);
     const lines = bodyBuf.toString().split('\n');
-    lines.forEach((n, index) => {
+    lines.forEach((n: string, index: number) => {
       const line = n.trim();
       if (!line) {
         return;
@@ -42,23 +41,23 @@ export class FileAdapter implements Adapter {
   /**
    * addPolicy adds a policy rule to the storage.
    */
-  public addPolicy(sec: string, ptype: string, rule: string[]): void {
+  public async addPolicy(sec: string, ptype: string, rule: string[]): Promise<void> {
     throw new Error('not implemented');
   }
 
   /**
    * savePolicy saves all policy rules to the storage.
    */
-  public savePolicy(model: Model): void {
+  public async savePolicy(model: Model): Promise<boolean> {
     if (!this.filePath) {
       // throw new Error('invalid file path, file path cannot be empty');
-      return;
+      return false;
     }
     let result = '';
 
     const pList = model.model.get('p');
     if (!pList) {
-      return;
+      return false;
     }
     pList.forEach(n => {
       n.policy.forEach(m => {
@@ -70,7 +69,7 @@ export class FileAdapter implements Adapter {
 
     const gList = model.model.get('g');
     if (!gList) {
-      return;
+      return false;
     }
     gList.forEach(n => {
       n.policy.forEach(m => {
@@ -80,24 +79,25 @@ export class FileAdapter implements Adapter {
       });
     });
 
-    this.savePolicyFile(result.trim());
+    await this.savePolicyFile(result.trim());
+    return true;
   }
 
-  private savePolicyFile(text: string) {
-    writeFileSync(this.filePath, text);
+  private async savePolicyFile(text: string): Promise<void> {
+    await writeFile(this.filePath, text);
   }
 
   /**
    * removePolicy removes a policy rule from the storage.
    */
-  public removePolicy(sec: string, ptype: string, rule: string[]): void {
+  public async removePolicy(sec: string, ptype: string, rule: string[]): Promise<void> {
     throw new Error('not implemented');
   }
 
   /**
    * removeFilteredPolicy removes policy rules that match the filter from the storage.
    */
-  public removeFilteredPolicy(sec: string, ptype: string, fieldIndex: number, ...fieldValues: string[]): void {
+  public async removeFilteredPolicy(sec: string, ptype: string, fieldIndex: number, ...fieldValues: string[]): Promise<void> {
     throw new Error('not implemented');
   }
 }
diff --git a/src/persist/filteredAdapter.ts b/src/persist/filteredAdapter.ts
index 9555cd1..924f0e6 100644
--- a/src/persist/filteredAdapter.ts
+++ b/src/persist/filteredAdapter.ts
@@ -3,7 +3,7 @@ import { Adapter } from './adapter';
 
 export interface FilteredAdapter extends Adapter {
   // loadFilteredPolicy loads only policy rules that match the filter.
-  loadFilteredPolicy(model: Model, filter: any): void;
+  loadFilteredPolicy(model: Model, filter: any): Promise<void>;
   // isFiltered returns true if the loaded policy has been filtered.
   isFiltered(): boolean;
 }
diff --git a/src/util/util.ts b/src/util/util.ts
index e06969c..482e535 100644
--- a/src/util/util.ts
+++ b/src/util/util.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import * as _ from 'lodash';
+import * as fs from 'fs';
 
 // escapeAssertion escapes the dots in the assertion,
 // because the expression evaluation doesn't support such variable names.
@@ -58,6 +59,30 @@ function setEquals(a: string[], b: string[]): boolean {
   return _.isEqual(_.sortedUniq(a), _.sortedUniq(b));
 }
 
+// readFile return a promise for readFile.
+function readFile(path: string, encoding?: string): any {
+  return new Promise((resolve, reject) => {
+    fs.readFile(path, encoding || 'utf8', (error, data) => {
+      if (error) {
+        reject(error);
+      }
+      resolve(data);
+    });
+  });
+}
+
+// writeFile return a promise for writeFile.
+function writeFile(path: string, file: string, encoding?: string): any {
+  return new Promise((resolve, reject) => {
+    fs.writeFile(path, file, encoding || 'utf8', (error) => {
+      if (error) {
+        reject(error);
+      }
+      resolve(true);
+    });
+  });
+}
+
 export {
   escapeAssertion,
   removeComments,
@@ -66,5 +91,7 @@ export {
   arrayRemoveDuplicates,
   arrayToString,
   paramsToString,
-  setEquals
+  setEquals,
+  readFile,
+  writeFile
 };
diff --git a/test/enforcer.test.ts b/test/enforcer.test.ts
index 3fe45bf..c18c04b 100644
--- a/test/enforcer.test.ts
+++ b/test/enforcer.test.ts
@@ -19,7 +19,7 @@ function testEnforce(e: Enforcer, sub: string, obj: string, act: string, res: bo
   expect(e.enforce(sub, obj, act)).toBe(res);
 }
 
-test('TestKeyMatchModelInMemory', () => {
+test('TestKeyMatchModelInMemory', async () => {
   const m = Enforcer.newModel();
   m.addDef('r', 'r', 'sub, obj, act');
   m.addDef('p', 'p', 'sub, obj, act');
@@ -29,6 +29,7 @@ test('TestKeyMatchModelInMemory', () => {
   const a = new FileAdapter('examples/keymatch_policy.csv');
 
   let e = new Enforcer(m, a);
+  await e.initialize();
 
   testEnforce(e, 'alice', '/alice_data/resource1', 'GET', true);
   testEnforce(e, 'alice', '/alice_data/resource1', 'POST', true);
@@ -53,7 +54,7 @@ test('TestKeyMatchModelInMemory', () => {
   testEnforce(e, 'cathy', '/cathy_data', 'DELETE', false);
 
   e = new Enforcer(m);
-  a.loadPolicy(e.getModel());
+  await e.initialize();
 
   testEnforce(e, 'alice', '/alice_data/resource1', 'GET', true);
   testEnforce(e, 'alice', '/alice_data/resource1', 'POST', true);
@@ -78,7 +79,7 @@ test('TestKeyMatchModelInMemory', () => {
   testEnforce(e, 'cathy', '/cathy_data', 'DELETE', false);
 });
 
-test('TestKeyMatchModelInMemoryDeny', () => {
+test('TestKeyMatchModelInMemoryDeny', async () => {
   const m = Enforcer.newModel();
   m.addDef('r', 'r', 'sub, obj, act');
   m.addDef('p', 'p', 'sub, obj, act');
@@ -88,6 +89,7 @@ test('TestKeyMatchModelInMemoryDeny', () => {
   const a = new FileAdapter('examples/keymatch_policy.csv');
 
   const e = new Enforcer(m, a);
+  await e.initialize();
 
   testEnforce(e, 'alice', '/alice_data/resource2', 'POST', true);
 });
diff --git a/test/model.test.ts b/test/model.test.ts
index 2764b40..0aa9643 100644
--- a/test/model.test.ts
+++ b/test/model.test.ts
@@ -27,8 +27,9 @@ function testDomainEnforce(e: Enforcer, sub: string, dom: string, obj: string, a
   expect(e.enforce(sub, dom, obj, act)).toBe(res);
 }
 
-test('TestBasicModel', () => {
+test('TestBasicModel', async () => {
   const e = new Enforcer('examples/basic_model.conf', 'examples/basic_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', true);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -40,8 +41,9 @@ test('TestBasicModel', () => {
   testEnforce(e, 'bob', 'data2', 'write', true);
 });
 
-test('TestBasicModelNoPolicy', () => {
+test('TestBasicModelNoPolicy', async () => {
   const e = new Enforcer('examples/basic_model.conf');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', false);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -53,8 +55,9 @@ test('TestBasicModelNoPolicy', () => {
   testEnforce(e, 'bob', 'data2', 'write', false);
 });
 
-test('TestBasicModelWithRoot', () => {
+test('TestBasicModelWithRoot', async () => {
   const e = new Enforcer('examples/basic_with_root_model.conf', 'examples/basic_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', true);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -70,8 +73,9 @@ test('TestBasicModelWithRoot', () => {
   testEnforce(e, 'root', 'data2', 'write', true);
 });
 
-test('TestBasicModelWithRootNoPolicy', () => {
+test('TestBasicModelWithRootNoPolicy', async () => {
   const e = new Enforcer('examples/basic_with_root_model.conf');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', false);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -87,8 +91,9 @@ test('TestBasicModelWithRootNoPolicy', () => {
   testEnforce(e, 'root', 'data2', 'write', true);
 });
 
-test('TestBasicModelWithoutUsers', () => {
+test('TestBasicModelWithoutUsers', async () => {
   const e = new Enforcer('examples/basic_without_users_model.conf', 'examples/basic_without_users_policy.csv');
+  await e.initialize();
 
   testEnforceWithoutUsers(e, 'data1', 'read', true);
   testEnforceWithoutUsers(e, 'data1', 'write', false);
@@ -96,8 +101,9 @@ test('TestBasicModelWithoutUsers', () => {
   testEnforceWithoutUsers(e, 'data2', 'write', true);
 });
 
-test('TestBasicModelWithoutResources', () => {
+test('TestBasicModelWithoutResources', async () => {
   const e = new Enforcer('examples/basic_without_resources_model.conf', 'examples/basic_without_resources_policy.csv');
+  await e.initialize();
 
   testEnforceWithoutUsers(e, 'alice', 'read', true);
   testEnforceWithoutUsers(e, 'alice', 'write', false);
@@ -105,8 +111,9 @@ test('TestBasicModelWithoutResources', () => {
   testEnforceWithoutUsers(e, 'bob', 'write', true);
 });
 
-test('TestRBACModel', () => {
+test('TestRBACModel', async () => {
   const e = new Enforcer('examples/rbac_model.conf', 'examples/rbac_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', true);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -118,8 +125,9 @@ test('TestRBACModel', () => {
   testEnforce(e, 'bob', 'data2', 'write', true);
 });
 
-test('TestRBACModelWithResourceRoles', () => {
+test('TestRBACModelWithResourceRoles', async () => {
   const e = new Enforcer('examples/rbac_with_resource_roles_model.conf', 'examples/rbac_with_resource_roles_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', true);
   testEnforce(e, 'alice', 'data1', 'write', true);
@@ -131,8 +139,9 @@ test('TestRBACModelWithResourceRoles', () => {
   testEnforce(e, 'bob', 'data2', 'write', true);
 });
 
-test('TestRBACModelWithDomains', () => {
+test('TestRBACModelWithDomains', async () => {
   const e = new Enforcer('examples/rbac_with_domains_model.conf', 'examples/rbac_with_domains_policy.csv');
+  await e.initialize();
 
   testDomainEnforce(e, 'alice', 'domain1', 'data1', 'read', true);
   testDomainEnforce(e, 'alice', 'domain1', 'data1', 'write', true);
@@ -154,8 +163,9 @@ class TestResource {
   }
 }
 
-test('TestABACModel', () => {
+test('TestABACModel', async () => {
   const e = new Enforcer('examples/abac_model.conf');
+  await e.initialize();
 
   const data1 = new TestResource('data1', 'alice');
   const data2 = new TestResource('data2', 'bob');
@@ -170,8 +180,9 @@ test('TestABACModel', () => {
   testEnforce(e, 'bob', data2, 'write', true);
 });
 
-test('TestKeyMatchModel', () => {
+test('TestKeyMatchModel', async () => {
   const e = new Enforcer('examples/keymatch_model.conf', 'examples/keymatch_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', '/alice_data/resource1', 'GET', true);
   testEnforce(e, 'alice', '/alice_data/resource1', 'POST', true);
@@ -196,8 +207,9 @@ test('TestKeyMatchModel', () => {
   testEnforce(e, 'cathy', '/cathy_data', 'DELETE', false);
 });
 
-test('TestKeyMatch2Model', () => {
+test('TestKeyMatch2Model', async () => {
   const e = new Enforcer('examples/keymatch2_model.conf', 'examples/keymatch2_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', '/alice_data', 'GET', false);
   testEnforce(e, 'alice', '/alice_data/resource1', 'GET', true);
@@ -222,8 +234,9 @@ function customFunctionWrapper(...args: any[]): boolean {
   return customFunction(name1, name2);
 }
 
-test('TestKeyMatchCustomModel', () => {
+test('TestKeyMatchCustomModel', async () => {
   const e = new Enforcer('examples/keymatch_custom_model.conf', 'examples/keymatch2_policy.csv');
+  await e.initialize();
 
   e.addFunction('keyMatchCustom', customFunctionWrapper);
 
@@ -231,8 +244,9 @@ test('TestKeyMatchCustomModel', () => {
   testEnforce(e, 'alice', '/alice_data2/myid/using/res_id', 'GET', true);
 });
 
-test('TestIPMatchModel', () => {
+test('TestIPMatchModel', async () => {
   const e = new Enforcer('examples/ipmatch_model.conf', 'examples/ipmatch_policy.csv');
+  await e.initialize();
 
   testEnforce(e, '192.168.2.123', 'data1', 'read', true);
   testEnforce(e, '192.168.2.123', 'data1', 'write', false);
@@ -255,8 +269,9 @@ test('TestIPMatchModel', () => {
   testEnforce(e, '192.168.0.1', 'data2', 'write', false);
 });
 
-test('TestPriorityModel', () => {
+test('TestPriorityModel', async () => {
   const e = new Enforcer('examples/priority_model.conf', 'examples/priority_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', true);
   testEnforce(e, 'alice', 'data1', 'write', false);
@@ -268,8 +283,9 @@ test('TestPriorityModel', () => {
   testEnforce(e, 'bob', 'data2', 'write', false);
 });
 
-test('TestPriorityModelIndeterminate', () => {
+test('TestPriorityModelIndeterminate', async () => {
   const e = new Enforcer('examples/priority_model.conf', 'examples/priority_indeterminate_policy.csv');
+  await e.initialize();
 
   testEnforce(e, 'alice', 'data1', 'read', false);
 });
diff --git a/yarn.lock b/yarn.lock
index 605b03b..f502a88 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2412,11 +2412,7 @@ lodash.sortby@^4.7.0:
   version "4.7.0"
   resolved "http://registry.npm.taobao.org/lodash.sortby/download/lodash.sortby-4.7.0.tgz#edd14c824e2cc9c1e0b0a1b42bb5210516a42438"
 
-lodash@^4.13.1, lodash@^4.17.4, lodash@^4.17.5:
-  version "4.17.10"
-  resolved "http://registry.npm.taobao.org/lodash/download/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
-
-lodash@^4.17.10:
+lodash@^4.13.1, lodash@^4.17.10, lodash@^4.17.4, lodash@^4.17.5:
   version "4.17.10"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"