Remove default values from config that have default values even when not present at all

__tests__/purgeUnusedStyles.test.js

@@ -58,6 +58,8 @@ const config = {
   },
 }
 
+delete config.presets
+
 function assertPurged(result) {
   expect(result.css).not.toContain('.bg-red-600')
   expect(result.css).not.toContain('.w-1\\/3')

__tests__/variantsAtRule.test.js

@@ -1,10 +1,12 @@
 import postcss from 'postcss'
 import plugin from '../src/lib/substituteVariantsAtRules'
 import processPlugins from '../src/util/processPlugins'
+import resolveConfig from '../src/util/resolveConfig'
 import config from '../stubs/defaultConfig.stub.js'
 
 function run(input, opts = config) {
-  return postcss([plugin(opts, processPlugins(opts.plugins, opts))]).process(input, {
+  const resolved = resolveConfig([opts])
+  return postcss([plugin(resolved, processPlugins(resolved.plugins, resolved))]).process(input, {
     from: undefined,
   })
 }

src/util/resolveConfig.js

@@ -220,6 +220,11 @@ export default function resolveConfig(configs) {
       corePlugins: resolveCorePlugins(allConfigs.map((c) => c.corePlugins)),
       plugins: resolvePluginLists(configs.map((c) => get(c, 'plugins', []))),
     },
-    ...allConfigs
+    ...allConfigs,
+    {
+      prefix: '',
+      important: false,
+      separator: ':',
+    }
   )
 }

stubs/defaultConfig.stub.js

@@ -4,9 +4,7 @@ module.exports = {
     // purgeLayersByDefault: true,
   },
   purge: [],
-  prefix: '',
-  important: false,
-  separator: ':',
+  presets: [],
   theme: {
     screens: {
       sm: '640px',
@@ -818,6 +816,5 @@ module.exports = {
     transitionDelay: ['responsive'],
     animation: ['responsive'],
   },
-  corePlugins: {},
   plugins: [],
 }