feat: replace the @global for :global for CSS modules compliance

src/transformers/globalRule.ts

@@ -1,19 +1,15 @@
 import postcss from 'postcss';
 
 import { Transformer } from '../types';
-import { globalifyPlugin } from './globalStyle';
+import { wrapSelectorInGlobal } from './globalStyle';
 
 const globalifyRulePlugin = (root: any) => {
-  root.walkAtRules(/^global$/, (atrule: any) => {
-    globalifyPlugin(atrule);
-    let after = atrule;
-
-    atrule.each(function (child: any) {
-      after.after(child);
-      after = child;
-    });
-
-    atrule.remove();
+  root.walkRules(/:global(?!\()/, (rule: any) => {
+    const [beginning, ...rest] = rule.selector.split(/:global(?!\()/);
+    rule.selector = (
+      beginning.trim() + ' '
+      + rest.filter((x: string) => !!x).map(wrapSelectorInGlobal).join(' ')
+    ).trim();
   });
 };
 

src/transformers/globalStyle.ts

@@ -2,7 +2,23 @@ import postcss from 'postcss';
 
 import { Transformer } from '../types';
 
-export const globalifyPlugin = (root: any) => {
+export const wrapSelectorInGlobal = (selector: string) => {
+  return selector
+    .trim()
+    .split(' ')
+    .map((selectorPart) => {
+      if (selectorPart.startsWith(':local')) {
+        return selectorPart.replace(/:local\((.+?)\)/g, '$1');
+      }
+      if (selectorPart.startsWith(':global')) {
+        return selectorPart;
+      }
+      return `:global(${selectorPart})`;
+    })
+    .join(' ');
+};
+
+const globalifyPlugin = (root: any) => {
   root.walkAtRules(/keyframes$/, (atrule: any) => {
     if (!atrule.params.startsWith('-global-')) {
       atrule.params = '-global-' + atrule.params;
@@ -14,20 +30,7 @@ export const globalifyPlugin = (root: any) => {
       return;
     }
 
-    rule.selectors = rule.selectors.map((selector: string) => {
-      return selector
-        .split(' ')
-        .map((selectorPart) => {
-          if (selectorPart.startsWith(':local')) {
-            return selectorPart.replace(/:local\((.+?)\)/g, '$1');
-          }
-          if (selectorPart.startsWith(':global')) {
-            return selectorPart;
-          }
-          return `:global(${selectorPart})`;
-        })
-        .join(' ');
-    });
+    rule.selectors = rule.selectors.map(wrapSelectorInGlobal);
   });
 };
 

test/transformers/globalRule.test.ts

@@ -3,40 +3,78 @@ import { preprocess } from '../utils';
 
 describe('transformer - globalRule', () => {
   it('wraps selector in :global(...) modifier', async () => {
-    const template = `<style>@global{div{color:red}.test{}}</style>`;
+    const template = `<style>:global div{color:red}:global .test{}</style>`;
     const opts = autoProcess();
     const preprocessed = await preprocess(template, opts);
     expect(preprocessed.toString()).toContain(
       `:global(div){color:red}:global(.test){}`,
     );
   });
 
-  it('wraps selector in :global(...) modifier only inside the rule', async () => {
-    const template = `<style>@global{div{color:red}}.test{}</style>`;
+  it('wraps selector in :global(...) only if needed', async () => {
+    const template = `<style>:global .test{}:global :global(.foo){}</style>`;
     const opts = autoProcess();
     const preprocessed = await preprocess(template, opts);
     expect(preprocessed.toString()).toContain(
-      `:global(div){color:red}.test{}`,
+      `:global(.test){}:global(.foo){}`,
     );
   });
 
-  it('wraps selector in :global(...) only if needed', async () => {
-    const template = `<style>@global{.test{}:global(.foo){}}</style>`;
+  it('wraps selector in :global(...) on multiple levels', async () => {
+    const template = '<style>:global div .cls{}</style>';
     const opts = autoProcess();
     const preprocessed = await preprocess(template, opts);
-    expect(preprocessed.toString()).toContain(
-      `:global(.test){}:global(.foo){}`,
+    expect(preprocessed.toString()).toMatch(
+      // either be :global(div .cls){}
+      //        or :global(div) :global(.cls){}
+      /(:global\(div .cls\)\{\}|:global\(div\) :global\(\.cls\)\{\})/,
     );
   });
 
-  it("prefixes @keyframes names with '-global-' only if needed", async () => {
-    const template = `<style>
-      @global{@keyframes a {from{} to{}}@keyframes -global-b {from{} to{}}}
-    </style>`;
+  it('wraps selector in :global(...) on multiple levels when in the middle', async () => {
+    const template = '<style>div :global span .cls{}</style>';
     const opts = autoProcess();
     const preprocessed = await preprocess(template, opts);
-    expect(preprocessed.toString()).toContain(
-      `@keyframes -global-a {from{} to{}}@keyframes -global-b {from{} to{}}`,
+    expect(preprocessed.toString()).toMatch(
+      // either be div :global(span .cls) {}
+      //        or div :global(span) :global(.cls) {}
+      /div (:global\(span .cls\)\{\}|:global\(span\) :global\(\.cls\)\{\})/,
+    );
+  });
+
+  it('does not break when at the end', async () => {
+    const template = '<style>span :global{}</style>';
+    const opts = autoProcess();
+    const preprocessed = await preprocess(template, opts);
+    expect(preprocessed.toString()).toContain('span{}');
+  });
+
+  it('works with collapsed nesting several times', async () => {
+    const template = '<style>div :global span :global .cls{}</style>';
+    const opts = autoProcess();
+    const preprocessed = await preprocess(template, opts);
+    expect(preprocessed.toString()).toMatch(
+      // either be div :global(span .cls) {}
+      //        or div :global(span) :global(.cls) {}
+      /div (:global\(span .cls\)\{\}|:global\(span\) :global\(\.cls\)\{\})/,
+    );
+  });
+
+  it('does not interfere with the :global(...) syntax', async () => {
+    const template = '<style>div :global(span){}</style>';
+    const opts = autoProcess();
+    const preprocessed = await preprocess(template, opts);
+    expect(preprocessed.toString()).toContain('div :global(span){}');
+  });
+
+  it('allows mixing with the :global(...) syntax', async () => {
+    const template = '<style>div :global(span) :global .cls{}</style>';
+    const opts = autoProcess();
+    const preprocessed = await preprocess(template, opts);
+    expect(preprocessed.toString()).toMatch(
+      // either be div :global(span .cls) {}
+      //        or div :global(span) :global(.cls) {}
+      /div (:global\(span .cls\)\{\}|:global\(span\) :global\(\.cls\)\{\})/,
     );
   });
 });