Revert "fix(compiler): support one additional level of nesting in :host()"

mattrbeck · thePunderWoman · commit f689269ecaf3 · 2025-11-13T15:44:25.000-08:00
This reverts commit 036c5d2.
diff --git a/packages/compiler/src/shadow_css.ts b/packages/compiler/src/shadow_css.ts
@@ -1045,13 +1045,7 @@ const _cssContentUnscopedRuleRe =
 const _polyfillHost = '-shadowcsshost';
 // note: :host-context pre-processed to -shadowcsshostcontext.
 const _polyfillHostContext = '-shadowcsscontext';
-// Matches text content with no parentheses, e.g., "foo"
-const _noParens = '[^)(]*';
-// Matches content with at most ONE level of nesting, e.g., "a(b)c"
-const _level1Parens = String.raw`(?:\(${_noParens}\)|${_noParens})+?`;
-// Matches content with at most TWO levels of nesting, e.g., "a(b(c)d)e"
-const _level2Parens = String.raw`(?:\(${_level1Parens}\)|${_noParens})+?`;
-const _parenSuffix = String.raw`(?:\((${_level2Parens})\))`;
+const _parenSuffix = '(?:\\((' + '(?:\\([^)(]*\\)|[^)(]*)+?' + ')\\))';
 const _cssColonHostRe = new RegExp(_polyfillHost + _parenSuffix + '?([^,{]*)', 'gim');
 // note: :host-context patterns are terminated with `{`, as opposed to :host which
 // is both `{` and `,` because :host-context handles top-level commas differently.
diff --git a/packages/compiler/test/shadow_css/host_and_host_context_spec.ts b/packages/compiler/test/shadow_css/host_and_host_context_spec.ts
@@ -83,9 +83,6 @@ describe('ShadowCss, :host and :host-context', () => {
       expect(shim(':host(:not(p)):before {}', 'contenta', 'a-host')).toEqualCss(
         '[a-host]:not(p):before {}',
       );
-      expect(shim(':host(:not(:has(p))) {}', 'contenta', 'a-host')).toEqualCss(
-        '[a-host]:not(:has(p)) {}',
-      );
       expect(shim(':host:not(:host.foo) {}', 'contenta', 'a-host')).toEqualCss(
         '[a-host]:not([a-host].foo) {}',
       );
