vue create my-component-library

import vue from 'rollup-plugin-vue';
import babel from 'rollup-plugin-babel';
import commonjs from 'rollup-plugin-commonjs';
import resolve from 'rollup-plugin-node-resolve';
import { terser } from 'rollup-plugin-terser';
export default [
  {
    input: 'src/main.js',
    output: [
      {
        file: 'dist/my-component-library.js',
        format: 'esm',
      },
      {
        file: 'dist/my-component-library.min.js',
        format: 'esm',
        plugins: [
          terser({
            output: {
              ecma: 6,
            },
          }),
        ],
      },
    ],
    plugins: [
      vue(),
      resolve({
        extensions: ['.js', '.vue'],
      }),
      commonjs(),
      babel({
        exclude: 'node_modules/**',
        plugins: ['@babel/external-helpers'],
      }),
    ],
    external: ['vue'],
  },
];

<template>
  <button class="btn" :class="type">{{ text }}</button>
</template>
<script>
export default {
  name: 'Button',
  props: {
    text: {
      type: String,
      required: true,
    },
    type: {
      type: String,
      default: 'primary',
    },
  },
};
</script>
<style>
.btn {
  padding: 10px 20px;
  border-radius: 5px;
  font-size: 16px;
  cursor: pointer;
}
.primary {
  background-color: #42b983;
  color: #fff;
}
.secondary {
  background-color: #fff;
  color: #42b983;
  border: 1px solid #42b983;
}
</style>

import Button from './components/Button.vue';
export { Button };

{
  "name": "my-component-library",
  "version": "1.0.0",
  "description": "A Vue component library",
  "main": "dist/my-component-library.js",
  "module": "dist/my-component-library.esm.js",
  "files": [
    "dist/*",
    "src/*"
  ],
  "scripts": {
    "build": "rollup -c",
    "dev": "rollup -c -w",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "vue",
    "component",
    "library"
  ],
  "author": "Your Name",
  "license": "MIT",
  "dependencies": {
    "vue": "^2.6.10"
  },
  "devDependencies": {
    "@babel/core": "^7.4.5",
    "@babel/preset-env": "^7.4.5",
    "@vue/component-compiler-utils": "^3.1.1",
    "babel-plugin-external-helpers": "^6.22.0",
    "rollup": "^1.20.0",
    "rollup-plugin-babel": "^4.3.3",
    "rollup-plugin-commonjs": "^10.0.0",
    "rollup-plugin-node-resolve": "^5.2.0",
    "rollup-plugin-terser": "^5.1.2",
    "rollup-plugin-vue": "^5.1.9"
  }
}

npm install

npm run build

npm login

npm publish

npm install my-component-library

import { Button } from 'my-component-library';
export default {
  name: 'App',
  components: {
    Button,
  },
};