diff --git a/lib/asset-js.js b/lib/asset-js.js
index 0b9766aa..d53f4d82 100644
--- a/lib/asset-js.js
+++ b/lib/asset-js.js
@@ -1,7 +1,8 @@
-
-
 import { uriIsRelative, pathnameBuilder } from './utils.js';
-import { buildScriptElement, buildReactScriptAttributes } from './html-utils.js';
+import {
+    buildScriptElement,
+    buildReactScriptAttributes,
+} from './html-utils.js';
 
 const inspect = Symbol.for('nodejs.util.inspect.custom');
 
@@ -29,6 +30,23 @@ export default class PodiumAssetJs {
     #data;
     #strategy;
     #scope;
+
+    /**
+     * @param {object} options
+     * @param {string} [options.referrerpolicy]
+     * @param {string} [options.crossorigin]
+     * @param {string} [options.integrity]
+     * @param {string} [options.pathname]
+     * @param {boolean} [options.nomodule=false]
+     * @param {boolean} [options.prefix=false]
+     * @param {string} [options.value]
+     * @param {boolean} [options.async=false]
+     * @param {boolean} [options.defer=false]
+     * @param {string} [options.type="default"]
+     * @param {array} [options.data]
+     * @param {string} [options.strategy]
+     * @param {string} [options.scope]
+     */
     constructor({
         referrerpolicy = '',
         crossorigin = undefined,
@@ -44,11 +62,12 @@ export default class PodiumAssetJs {
         strategy = undefined,
         scope = undefined,
     } = {}) {
-        if (!toUndefined(value))
+        if (!toUndefined(value)) {
             throw new Error(
                 `Value for argument variable "value", "${value}", is not valid`,
             );
-        
+        }
+
         this.#pathname = pathname;
         this.#prefix = prefix;
         this.#value = value;
@@ -57,8 +76,15 @@ export default class PodiumAssetJs {
         this.#crossorigin = crossorigin;
         this.#integrity = integrity;
         this.#nomodule = nomodule;
-        this.#async = async;
-        this.#defer = defer;
+
+        if (async && defer) {
+            this.#async = false;
+            this.#defer = true;
+        } else {
+            this.#async = async;
+            this.#defer = defer;
+        }
+
         this.#type = type;
         this.#data = data;
         this.#strategy = strategy;
@@ -148,7 +174,7 @@ export default class PodiumAssetJs {
     }
 
     get strategy() {
-      return this.#strategy;
+        return this.#strategy;
     }
 
     set strategy(value) {
@@ -156,7 +182,7 @@ export default class PodiumAssetJs {
     }
 
     get scope() {
-      return this.#scope;
+        return this.#scope;
     }
 
     set scope(value) {
@@ -204,4 +230,4 @@ export default class PodiumAssetJs {
     get [Symbol.toStringTag]() {
         return 'PodiumAssetJs';
     }
-};
+}
diff --git a/tests/asset-js.js b/tests/asset-js.js
index 9cddb63f..754f16da 100644
--- a/tests/asset-js.js
+++ b/tests/asset-js.js
@@ -4,229 +4,301 @@ import AssetJs from '../lib/asset-js.js';
 
 tap.test('Js() - object tag - should be PodiumAssetJs', (t) => {
     const obj = new AssetJs({ value: '/foo' });
-    t.equal(Object.prototype.toString.call(obj), 
-        '[object PodiumAssetJs]',
-    );
+    t.equal(Object.prototype.toString.call(obj), '[object PodiumAssetJs]');
     t.end();
-}); 
+});
 
 tap.test('Js() - no value given to "value" argument', (t) => {
     t.plan(1);
-    t.throws(() => {
-        const obj = new AssetJs(); // eslint-disable-line no-unused-vars
-    }, /Value for argument variable "value", "undefined", is not valid/, 'Should throw');
-    t.end();
-}); 
-
-tap.test('Js() - no arguments given - should construct object with default values', (t) => {
-    const obj = new AssetJs({ value: '/foo' });
-    t.equal(obj.referrerpolicy, '');
-    t.equal(obj.crossorigin, undefined);
-    t.equal(obj.integrity, '');
-    t.notOk(obj.nomodule);
-    t.notOk(obj.async);
-    t.notOk(obj.defer);
-    t.equal(obj.value, '/foo');
-    t.equal(obj.type, 'default');
-    t.equal(obj.src, '/foo');
-    t.same(obj.data, []);
-    t.end();
-}); 
-
-tap.test('Js() - no arguments given - should construct JSON with default values', (t) => {
-    const obj = new AssetJs({ value: '/foo' });
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        value: '/foo',
-        type: 'default',
-    });
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is unset - should NOT append pathname to "value"', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
-    t.equal(obj.value, '/foo');
-    t.equal(obj.src, '/foo');
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is false - should NOT append pathname to "value"', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: false });
-    t.equal(obj.value, '/foo');
-    t.equal(obj.src, '/foo');
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is true - should append pathname to "value"', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: true });
-    t.equal(obj.value, '/bar/foo');
-    t.equal(obj.src, '/bar/foo');
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is unset - should NOT append pathname to "value" for toJSON()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        value: '/foo',
-        type: 'default',
-    });
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is false - should NOT append pathname to "value" for toJSON()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: false });
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        value: '/foo',
-        type: 'default',
-    });
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is true - should NOT append pathname to "value" for toJSON()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: true });
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        value: '/foo',
-        type: 'default',
-    });
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is unset - should NOT append pathname to "src" for toHTML()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
-    t.equal(obj.toHTML(), '<script src="/foo"></script>');
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is false - should NOT append pathname to "src" for toHTML()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: false });
-    t.equal(obj.value, '/foo');
-    t.equal(obj.toHTML(), '<script src="/foo"></script>');
-    t.end();
-}); 
-
-tap.test('Js() - pathname is given - prefix is true - should append pathname to "src" for toHTML()', (t) => {
-    const obj = new AssetJs({ value: '/foo', pathname: '/bar', prefix: true });
-    t.equal(obj.toHTML(), '<script src="/bar/foo"></script>');
-    t.end();
-}); 
-
-tap.test('Js() - value if absoulte - pathname is given - prefix is true - should NOT append pathname to "value"', (t) => {
-    const obj = new AssetJs({
-        value: 'http://somewhere.else.com/foo',
-        pathname: '/bar',
-        prefix: true,
-    });
-    t.equal(obj.value, 'http://somewhere.else.com/foo');
-    t.equal(obj.src, 'http://somewhere.else.com/foo');
-
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        value: 'http://somewhere.else.com/foo',
-        type: 'default',
-    });
-
-    t.equal(obj.toHTML(), 
-        '<script src="http://somewhere.else.com/foo"></script>',
-    );
-    t.end();
-}); 
-
-tap.test('Js() - set "referrerpolicy" - should construct object as t.equaled', (t) => {
-    const obj = new AssetJs({
-        value: '/foo',
-    });
-
-    obj.referrerpolicy = 'bar';
-
-    t.equal(obj.referrerpolicy, 'bar');
-    t.equal(obj.toHTML(), 
-        '<script src="/foo" referrerpolicy="bar"></script>',
-    );
-
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        referrerpolicy: 'bar',
-        value: '/foo',
-        type: 'default',
-    });
-
-    const repl = new AssetJs(json);
-    t.equal(repl.referrerpolicy, 'bar');
-    t.end();
-}); 
-
-tap.test('Js() - set "crossorigin" - should construct object as t.equaled', (t) => {
-    const obj = new AssetJs({
-        value: '/foo',
-    });
-
-    obj.crossorigin = 'bar';
-
-    t.equal(obj.crossorigin, 'bar');
-    t.equal(obj.toHTML(), 
-        '<script src="/foo" crossorigin="bar"></script>',
+    t.throws(
+        () => {
+            const obj = new AssetJs(); // eslint-disable-line no-unused-vars
+        },
+        /Value for argument variable "value", "undefined", is not valid/,
+        'Should throw',
     );
-
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        crossorigin: 'bar',
-        value: '/foo',
-        type: 'default',
-    });
-
-    const repl = new AssetJs(json);
-    t.equal(repl.crossorigin, 'bar');
     t.end();
-}); 
-
-tap.test('Js() - set "integrity" - should construct object as t.equaled', (t) => {
-    const obj = new AssetJs({
-        value: '/foo',
-    });
-
-    obj.integrity = 'bar';
-
-    t.equal(obj.integrity, 'bar');
-    t.equal(obj.toHTML(), 
-        '<script src="/foo" integrity="bar"></script>',
-    );
-
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        integrity: 'bar',
-        value: '/foo',
-        type: 'default',
-    });
-
-    const repl = new AssetJs(json);
-    t.equal(repl.integrity, 'bar');
-    t.end();
-}); 
-
-tap.test('Js() - set "nomodule" - should construct object as t.equaled', (t) => {
-    const obj = new AssetJs({
-        value: '/foo',
-    });
-
-    obj.nomodule = true;
-
-    t.ok(obj.nomodule);
-    t.equal(obj.toHTML(), '<script src="/foo" nomodule></script>');
-
-    const json = JSON.parse(JSON.stringify(obj));
-    t.same(json, {
-        nomodule: true,
-        value: '/foo',
-        type: 'default',
-    });
-
-    const repl = new AssetJs(json);
-    t.ok(repl.nomodule);
-    t.end();
-}); 
+});
+
+tap.test(
+    'Js() - no arguments given - should construct object with default values',
+    (t) => {
+        const obj = new AssetJs({ value: '/foo' });
+        t.equal(obj.referrerpolicy, '');
+        t.equal(obj.crossorigin, undefined);
+        t.equal(obj.integrity, '');
+        t.notOk(obj.nomodule);
+        t.notOk(obj.async);
+        t.notOk(obj.defer);
+        t.equal(obj.value, '/foo');
+        t.equal(obj.type, 'default');
+        t.equal(obj.src, '/foo');
+        t.same(obj.data, []);
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - no arguments given - should construct JSON with default values',
+    (t) => {
+        const obj = new AssetJs({ value: '/foo' });
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            value: '/foo',
+            type: 'default',
+        });
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is unset - should NOT append pathname to "value"',
+    (t) => {
+        const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
+        t.equal(obj.value, '/foo');
+        t.equal(obj.src, '/foo');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is false - should NOT append pathname to "value"',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: false,
+        });
+        t.equal(obj.value, '/foo');
+        t.equal(obj.src, '/foo');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is true - should append pathname to "value"',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: true,
+        });
+        t.equal(obj.value, '/bar/foo');
+        t.equal(obj.src, '/bar/foo');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is unset - should NOT append pathname to "value" for toJSON()',
+    (t) => {
+        const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            value: '/foo',
+            type: 'default',
+        });
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is false - should NOT append pathname to "value" for toJSON()',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: false,
+        });
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            value: '/foo',
+            type: 'default',
+        });
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is true - should NOT append pathname to "value" for toJSON()',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: true,
+        });
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            value: '/foo',
+            type: 'default',
+        });
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is unset - should NOT append pathname to "src" for toHTML()',
+    (t) => {
+        const obj = new AssetJs({ value: '/foo', pathname: '/bar' });
+        t.equal(obj.toHTML(), '<script src="/foo"></script>');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is false - should NOT append pathname to "src" for toHTML()',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: false,
+        });
+        t.equal(obj.value, '/foo');
+        t.equal(obj.toHTML(), '<script src="/foo"></script>');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - pathname is given - prefix is true - should append pathname to "src" for toHTML()',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+            pathname: '/bar',
+            prefix: true,
+        });
+        t.equal(obj.toHTML(), '<script src="/bar/foo"></script>');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - value if absoulte - pathname is given - prefix is true - should NOT append pathname to "value"',
+    (t) => {
+        const obj = new AssetJs({
+            value: 'http://somewhere.else.com/foo',
+            pathname: '/bar',
+            prefix: true,
+        });
+        t.equal(obj.value, 'http://somewhere.else.com/foo');
+        t.equal(obj.src, 'http://somewhere.else.com/foo');
+
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            value: 'http://somewhere.else.com/foo',
+            type: 'default',
+        });
+
+        t.equal(
+            obj.toHTML(),
+            '<script src="http://somewhere.else.com/foo"></script>',
+        );
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - set "referrerpolicy" - should construct object as t.equaled',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+        });
+
+        obj.referrerpolicy = 'bar';
+
+        t.equal(obj.referrerpolicy, 'bar');
+        t.equal(
+            obj.toHTML(),
+            '<script src="/foo" referrerpolicy="bar"></script>',
+        );
+
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            referrerpolicy: 'bar',
+            value: '/foo',
+            type: 'default',
+        });
+
+        const repl = new AssetJs(json);
+        t.equal(repl.referrerpolicy, 'bar');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - set "crossorigin" - should construct object as t.equaled',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+        });
+
+        obj.crossorigin = 'bar';
+
+        t.equal(obj.crossorigin, 'bar');
+        t.equal(obj.toHTML(), '<script src="/foo" crossorigin="bar"></script>');
+
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            crossorigin: 'bar',
+            value: '/foo',
+            type: 'default',
+        });
+
+        const repl = new AssetJs(json);
+        t.equal(repl.crossorigin, 'bar');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - set "integrity" - should construct object as t.equaled',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+        });
+
+        obj.integrity = 'bar';
+
+        t.equal(obj.integrity, 'bar');
+        t.equal(obj.toHTML(), '<script src="/foo" integrity="bar"></script>');
+
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            integrity: 'bar',
+            value: '/foo',
+            type: 'default',
+        });
+
+        const repl = new AssetJs(json);
+        t.equal(repl.integrity, 'bar');
+        t.end();
+    },
+);
+
+tap.test(
+    'Js() - set "nomodule" - should construct object as t.equaled',
+    (t) => {
+        const obj = new AssetJs({
+            value: '/foo',
+        });
+
+        obj.nomodule = true;
+
+        t.ok(obj.nomodule);
+        t.equal(obj.toHTML(), '<script src="/foo" nomodule></script>');
+
+        const json = JSON.parse(JSON.stringify(obj));
+        t.same(json, {
+            nomodule: true,
+            value: '/foo',
+            type: 'default',
+        });
+
+        const repl = new AssetJs(json);
+        t.ok(repl.nomodule);
+        t.end();
+    },
+);
 
 tap.test('Js() - set "async" - should construct object as t.equaled', (t) => {
     const obj = new AssetJs({
@@ -248,7 +320,7 @@ tap.test('Js() - set "async" - should construct object as t.equaled', (t) => {
     const repl = new AssetJs(json);
     t.ok(repl.async);
     t.end();
-}); 
+});
 
 tap.test('Js() - set "defer" - should construct object as t.equaled', (t) => {
     const obj = new AssetJs({
@@ -270,7 +342,7 @@ tap.test('Js() - set "defer" - should construct object as t.equaled', (t) => {
     const repl = new AssetJs(json);
     t.ok(repl.defer);
     t.end();
-}); 
+});
 
 tap.test('Js() - set "type" - should construct object as t.equaled', (t) => {
     const obj = new AssetJs({
@@ -291,66 +363,93 @@ tap.test('Js() - set "type" - should construct object as t.equaled', (t) => {
     const repl = new AssetJs(json);
     t.equal(repl.type, 'esm');
     t.end();
-}); 
+});
 
 tap.test('Js() - set "data" - should construct object as t.equaled', (t) => {
     const obj = new AssetJs({
         value: '/foo',
     });
 
-    obj.data = [{ 
-        key: 'foo',
-        value: 'bar'     
-    }];
+    obj.data = [
+        {
+            key: 'foo',
+            value: 'bar',
+        },
+    ];
 
-    t.same(obj.data, [{ 
-        key: 'foo',
-        value: 'bar'     
-    }]);
+    t.same(obj.data, [
+        {
+            key: 'foo',
+            value: 'bar',
+        },
+    ]);
     t.equal(obj.toHTML(), '<script src="/foo" data-foo="bar"></script>');
 
     const json = JSON.parse(JSON.stringify(obj));
     t.same(json, {
         value: '/foo',
-        data: [{ 
-            key: 'foo',
-            value: 'bar'     
-        }],
+        data: [
+            {
+                key: 'foo',
+                value: 'bar',
+            },
+        ],
         type: 'default',
     });
 
     const repl = new AssetJs(json);
-    t.same(repl.data, [{ 
-        key: 'foo',
-        value: 'bar'     
-    }]);
+    t.same(repl.data, [
+        {
+            key: 'foo',
+            value: 'bar',
+        },
+    ]);
     t.end();
-}); 
+});
 
 tap.test('Js() - set "value"', (t) => {
     t.plan(1);
     const obj = new AssetJs({
         value: '/foo',
     });
-    t.throws(() => {
-        obj.value = '/bar';
-    }, /Cannot set read-only property./, 'Should throw');
+    t.throws(
+        () => {
+            obj.value = '/bar';
+        },
+        /Cannot set read-only property./,
+        'Should throw',
+    );
     t.end();
-}); 
+});
 
 tap.test('Js() - set "src"', (t) => {
     t.plan(1);
     const obj = new AssetJs({
         value: '/foo',
     });
-    t.throws(() => {
-        obj.src = '/bar';
-    }, /Cannot set read-only property./, 'Should throw');
+    t.throws(
+        () => {
+            obj.src = '/bar';
+        },
+        /Cannot set read-only property./,
+        'Should throw',
+    );
     t.end();
-}); 
+});
 
 tap.test('Js() - validate object against schema - should validate', (t) => {
     const obj = new AssetJs({ value: '/foo' });
     t.notOk(schema.js([obj]).error);
     t.end();
-}); 
+});
+
+tap.test('Js() - ignores async if both id and defer are set', (t) => {
+    const asset = new AssetJs({
+        value: '/foo',
+        async: true,
+        defer: true,
+    });
+    t.ok(asset.defer);
+    t.notOk(asset.async, 'Async should be ignored if defer is set');
+    t.end();
+});
diff --git a/tests/html-utils.js b/tests/html-utils.js
index 9dd0f774..cbefd627 100644
--- a/tests/html-utils.js
+++ b/tests/html-utils.js
@@ -12,7 +12,7 @@ tap.test('.buildLinkElement() - "value" property has a value - should appended "
         value: '/foo',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -24,7 +24,7 @@ tap.test('.buildLinkElement() - "crossorigin" property has a value - should appe
         crossorigin: 'bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" crossorigin="bar" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -36,7 +36,7 @@ tap.test('.buildLinkElement() - "disabled" property is "true" - should appended
         disabled: true,
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" disabled type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -48,7 +48,7 @@ tap.test('.buildLinkElement() - "hreflang" property has a value - should appende
         hreflang: 'bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" hreflang="bar" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -60,7 +60,7 @@ tap.test('.buildLinkElement() - "title" property has a value - should appended "
         title: 'bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" title="bar" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -72,7 +72,7 @@ tap.test('.buildLinkElement() - "media" property has a value - should appended "
         media: 'bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" media="bar" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -84,7 +84,7 @@ tap.test('.buildLinkElement() - "as" property has a value - should appended "as"
         as: 'bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" as="bar" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -123,7 +123,7 @@ tap.test('.buildLinkElement() - properties are "undefined" - should NOT appended
         as: undefined,
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         '<link href="/foo" type="text/css" rel="stylesheet">',
     );
     t.end();
@@ -186,7 +186,7 @@ tap.test('.buildLinkElement() - crossorigin boolean true', (t) => {
         value: '/bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         `<link href="/bar" crossorigin type="text/css" rel="stylesheet">`,
     );
     t.end();
@@ -198,7 +198,7 @@ tap.test('.buildLinkElement() - crossorigin boolean false', (t) => {
         value: '/bar',
     });
     const result = utils.buildLinkElement(obj);
-    t.equal(result, 
+    t.equal(result,
         `<link href="/bar" type="text/css" rel="stylesheet">`,
     );
     t.end();
@@ -441,17 +441,15 @@ tap.test('.buildScriptAttributes() - advanced', (t) => {
     const obj = new AssetJs({
         value: '/bar',
         crossorigin: true,
-        async: true,
         integrity: 'fake',
         defer: true,
         type: 'module',
     });
-    t.same(utils.buildScriptAttributes(obj), [ 
+    t.same(utils.buildScriptAttributes(obj), [
         { key: 'src', value: '/bar' },
         { key: 'type', value: 'module' },
         { key: 'crossorigin' },
         { key: 'integrity', value: 'fake' },
-        { key: 'async' },
         { key: 'defer' },
     ]);
     t.end();
@@ -459,7 +457,7 @@ tap.test('.buildScriptAttributes() - advanced', (t) => {
 
 tap.test('.buildLinkAttributes() - basic', (t) => {
     const obj = new AssetCss({ value: '/bar' });
-    t.same(utils.buildLinkAttributes(obj), [ 
+    t.same(utils.buildLinkAttributes(obj), [
         { key: 'href', value: '/bar' },
         { key: 'type', value: 'text/css' },
         { key: 'rel', value: 'stylesheet' },
@@ -497,15 +495,13 @@ tap.test('.buildReactScriptAttributes()', (t) => {
         value: '/bar',
         crossorigin: true,
         async: true,
-        defer: true,
         nomodule: true,
     });
-    t.same(utils.buildReactScriptAttributes(obj), { 
+    t.same(utils.buildReactScriptAttributes(obj), {
         src: '/bar',
         crossOrigin: '',
         noModule: true,
         async: true,
-        defer: true,
     });
     t.end();
 });
@@ -516,7 +512,7 @@ tap.test('.buildReactLinkAttributes()', (t) => {
         crossorigin: true,
         disabled: true,
     });
-    t.same(utils.buildReactLinkAttributes(obj), { 
+    t.same(utils.buildReactLinkAttributes(obj), {
         href: '/bar',
         crossOrigin: '',
         rel: 'stylesheet',