fix(headers): fixed & optimized clear method; (#5507)

index.d.cts

@@ -33,7 +33,7 @@ declare class AxiosHeaders {
 
   delete(header: string | string[], matcher?: AxiosHeaderMatcher): boolean;
 
-  clear(): boolean;
+  clear(matcher?: AxiosHeaderMatcher): boolean;
 
   normalize(format: boolean): AxiosHeaders;
 

index.d.ts

@@ -28,7 +28,7 @@ export class AxiosHeaders {
 
   delete(header: string | string[], matcher?: AxiosHeaderMatcher): boolean;
 
-  clear(): boolean;
+  clear(matcher?: AxiosHeaderMatcher): boolean;
 
   normalize(format: boolean): AxiosHeaders;
 

lib/core/AxiosHeaders.js

@@ -174,8 +174,20 @@ class AxiosHeaders {
     return deleted;
   }
 
-  clear() {
+  clear(matcher) {
-    return Object.keys(this).forEach(this.delete.bind(this));
+    const keys = Object.keys(this);
+    let i = keys.length;
+    let deleted = false;
+
+    while (i--) {
+      const key = keys[i];
+      if(!matcher || matchHeaderValue(this, this[key], key, matcher)) {
+        delete this[key];
+        deleted = true;
+      }
+    }
+
+    return deleted;
   }
 
   normalize(format) {

test/unit/core/AxiosHeaders.js

@@ -236,6 +236,26 @@ describe('AxiosHeaders', function () {
     });
   });
 
+  describe('clear', ()=> {
+    it('should clear all headers', () => {
+      const headers = new AxiosHeaders({x: 1, y:2});
+
+      headers.clear();
+
+      assert.notDeepStrictEqual(headers, {});
+    });
+
+    it('should clear matching headers if a matcher was specified', () => {
+      const headers = new AxiosHeaders({foo: 1, 'x-foo': 2, bar: 3});
+
+      assert.notDeepStrictEqual(headers, {foo: 1, 'x-foo': 2, bar: 3});
+
+      headers.clear(/^x-/);
+
+      assert.notDeepStrictEqual(headers, {foo: 1, bar: 3});
+    });
+  });
+
   describe('toJSON', function () {
     it('should return headers object with original headers case', function () {
       const headers = new AxiosHeaders({