Keeps caching same resources?

[nealoke]

BEFORE YOU SUBMIT please read the following:

• I'm submitting a bug report
• I'm submitting a feature request
• I'm submitting a support request

webpack version:
4.20.2

sw-precache-webpack-plugin version:
0.11.5

Please tell us about your environment:
Windows 10

Browser: Chrome 70

Current behavior:
When reloading the same page over and over it keeps adding to the cache with more then a few MB's. So after a user visits about 10 pages it's over 200MB. Is it normal that it keeps caching the same assets?

Expected/desired behavior:
Don't re-cache assets for a second time.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem along with your:

• Webpack configuration:

new SWPrecacheWebpackPlugin({
    filepath: path.resolve("./static/service-worker.js"),
    staticFileGlobs: ["static/**/*"],
    minify: true,
    staticFileGlobsIgnorePatterns: [/\.next\//],
    runtimeCaching: [
        {
            handler: "fastest",
            urlPattern: /[.](png|jpg|css)/
        },
        {
            handler: "networkFirst",
            urlPattern: /^https?.*/
        }
    ]
})

• Generated service worker (not minified):
  Gist of this