Your code is generally clean and functional. However, there are a few minor improvements you can make:

1. Template Literals: In the <template> part of your code, ensure that all template literals are properly closed with double quotes (").

2. Consistent Use of .value Property: It's important to consistently use the .value property when dealing with reactivity properties in Vue.js.

3. Function Naming Consistency: The function formatSize uses snake_case, while others like if, else if, etc., follow camelCase. Consider using consistent naming conventions throughout your codebase for clarity.

Here’s an optimized version of your code:

<template>
  <el-upload
    :style="{ width: '100%' }"
    v-loading="loading"
    action="#"
    v-bind="$attrs"
  ></el-upload>
</template>

<script lang="ts">
import { defineComponent, ref } from 'vue';
const formatSize = (sizeInBytes: number): string => {
  // Your implementation of formatting size goes here
};

const deleteFile = (file: any) => {
  if (!inputDisabled.value) {
    fileArray.value = fileArray.value.filter((f: any) => f.uid !== file.uid);
  }
};

export default defineComponent({
  name: 'YourComponentName',
  setup() {
    const loading = ref(true);
    const inputDisabled = ref(false); // Make sure this is also reactive
    const fileArray = ref([]); // Ensure this is reactive

    return {
      loading,
      inputDisabled,
      fileArray,
      formatSize,
      deleteFile,
    };
  },
});
</script>

<style scoped>
/* Your styles go here */
</style>

Key changes:

• Ensured consistent template literal usage.
• Used arrow functions where appropriate.
• Properly defined constants and returned them inside script tags.
• Made inputDisabled and fileArray reactive references by prefixing them with ref().

These changes should improve both readability and maintainability of your Vue component.