From 4743748ede30c2c16a2674d7a0d0f8c2bda4c29b Mon Sep 17 00:00:00 2001
From: Vladimir Sheremet <sleuths.slews0s@icloud.com>
Date: Fri, 5 Aug 2022 18:28:51 +0300
Subject: [PATCH] feat: add option to keep class names for css modules

---
 packages/vitest/src/node/config.ts            |  5 +++-
 .../vitest/src/node/plugins/cssEnabler.ts     | 26 ++++++++++++++++++-
 packages/vitest/src/types/config.ts           |  5 +++-
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/packages/vitest/src/node/config.ts b/packages/vitest/src/node/config.ts
index 866baf16b082..9898de672d35 100644
--- a/packages/vitest/src/node/config.ts
+++ b/packages/vitest/src/node/config.ts
@@ -185,8 +185,11 @@ export function resolveConfig(
     resolved.passWithNoTests ??= true
 
   resolved.css ??= {}
-  if (typeof resolved.css === 'object')
+  if (typeof resolved.css === 'object') {
     resolved.css.include ??= [/\.module\./]
+    resolved.css.modules ??= {}
+    resolved.css.modules.mangleClassName ??= false
+  }
 
   resolved.cache ??= { dir: '' }
   if (resolved.cache)
diff --git a/packages/vitest/src/node/plugins/cssEnabler.ts b/packages/vitest/src/node/plugins/cssEnabler.ts
index 6afa2548737b..b42b3f71417d 100644
--- a/packages/vitest/src/node/plugins/cssEnabler.ts
+++ b/packages/vitest/src/node/plugins/cssEnabler.ts
@@ -4,11 +4,16 @@ import type { Vitest } from '../core'
 
 const cssLangs = '\\.(css|less|sass|scss|styl|stylus|pcss|postcss)($|\\?)'
 const cssLangRE = new RegExp(cssLangs)
+const cssModuleRE = new RegExp(`\\.module${cssLangs}`)
 
 const isCSS = (id: string) => {
   return cssLangRE.test(id)
 }
 
+const isCSSModule = (id: string) => {
+  return cssModuleRE.test(id)
+}
+
 export function CSSEnablerPlugin(ctx: Vitest): VitePlugin {
   const shouldProcessCSS = (id: string) => {
     const { css } = ctx.config
@@ -21,14 +26,33 @@ export function CSSEnablerPlugin(ctx: Vitest): VitePlugin {
     return false
   }
 
+  const shouldReturnProxy = (id: string) => {
+    const { css } = ctx.config
+    if (typeof css === 'boolean')
+      return css
+    if (!isCSSModule(id))
+      return false
+    return !css.modules?.mangleClassName
+  }
+
   return {
     name: 'vitest:css-enabler',
     enforce: 'pre',
     transform(code, id) {
       if (!isCSS(id))
         return
-      if (!shouldProcessCSS(id))
+      if (!shouldProcessCSS(id)) {
         return { code: '' }
+      }
+      else if (shouldReturnProxy(id)) {
+        // TODO parse and check if object actually exists
+        const code = `export default new Proxy(Object.create(null), {
+          get(_, style) {
+            return style;
+          },
+        })`
+        return { code }
+      }
     },
   }
 }
diff --git a/packages/vitest/src/types/config.ts b/packages/vitest/src/types/config.ts
index a78cf232976d..0d5c3a6befce 100644
--- a/packages/vitest/src/types/config.ts
+++ b/packages/vitest/src/types/config.ts
@@ -370,11 +370,14 @@ export interface InlineConfig {
    *
    * When excluded, the CSS files will be replaced with empty strings to bypass the subsequent processing.
    *
-   * @default { include: [/\.module\./] }
+   * @default { include: [/\.module\./], modules: { mangleClassName: false } }
    */
   css?: boolean | {
     include?: RegExp | RegExp[]
     exclude?: RegExp | RegExp[]
+    modules?: {
+      mangleClassName?: boolean
+    }
   }
   /**
    * A number of tests that are allowed to run at the same time marked with `test.concurrent`.