Add UMD build

[jaredpalmer]

Selfishly want this for forthcoming Formik docs site.

[jaredpalmer]

@jquense would you merge a PR that updates tooling with Rollup and adds this?

[jquense]

Sure!

[ravilution]

I need this badly as well. Please build a UMD that can be accessed via https://unpkg.com/.

[macklinu]

Some initial thoughts on resolving this issue:

• Update rollup.config.js to output a UMD bundle:

diff --git a/rollup.config.js b/rollup.config.js
index 442db4e..ae8c725 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -38,6 +38,11 @@ module.exports = [
         file: 'dist/yup.esm.js',
         format: 'es',
       },
+      {
+        file: 'dist/yup.umd.js',
+        format: 'umd',
+        name: 'Yup',
+      },
     ],
     plugins: [...base.plugins, filesize()],
   },

• Update package.json#main to point to the UMD bundle instead of the CommonJS bundle (possibly?)
• Update the build npm script to run Rollup in some way

What else might be involved here? Interested in helping resolve this.

[mikabytes]

Why was this issue closed? We're also looking for a UMD build of Yup, and there seem to be people interested in helping out adding support for this?

[lasseborly]

This is still very much relevant 👍