fix(babel): keep function names to improve stack traces in tests (#189)

* fix(babel): keep function names to improve stack traces in tests

Fixes #188

* fix(babel): remove minify babel plugin if minify env variable is false

Author: mpeyper

src/config/babelrc.js

@@ -17,6 +17,7 @@ const isRollup = parseEnv('BUILD_ROLLUP', false)
 const isUMD = BUILD_FORMAT === 'umd'
 const isCJS = BUILD_FORMAT === 'cjs'
 const isWebpack = parseEnv('BUILD_WEBPACK', false)
+const isMinify = parseEnv('BUILD_MINIFY', false)
 const treeshake = parseEnv('BUILD_TREESHAKE', isRollup || isWebpack)
 const alias = parseEnv('BUILD_ALIAS', isPreact ? {react: 'preact'} : null)
 
@@ -81,7 +82,9 @@ module.exports = () => ({
       ? require.resolve('babel-plugin-transform-inline-environment-variables')
       : null,
     [require.resolve('@babel/plugin-proposal-class-properties'), {loose: true}],
-    require.resolve('babel-plugin-minify-dead-code-elimination'),
+    isMinify
+      ? require.resolve('babel-plugin-minify-dead-code-elimination')
+      : null,
     treeshake
       ? null
       : require.resolve('@babel/plugin-transform-modules-commonjs'),