fix: add back-compat for Chromium <125

Signed-off-by: dankeboy36 <dankeboy36@gmail.com>

Author: dankeboy36

src/vscode-tree-item/vscode-tree-item.styles.ts

@@ -253,8 +253,12 @@ const styles: CSSResultGroup = [
     /* Electron v31+ (VS Code 1.95+) on Chromium 125 supports :state():
        https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/:state#browser_compatibility
        Update to Chromium to 126.0.6445.0: https://github.com/electron/electron/releases/tag/v31.0.0-beta.1
-       https://github.com/microsoft/vscode/blob/1.95.0/package.json#L155 */
-    :host(:state(has-decoration)) .decoration {
+       https://github.com/microsoft/vscode/blob/1.95.0/package.json#L155
+       Back-compat: older Chromium builds only understand the :--state form, so we
+       mirror the state under --has-decoration as well. */
+    :host(:--has-decoration) .decoration,
+    :host(:state(has-decoration)) .decoration,
+    :host(:state(--has-decoration)) .decoration {
       display: inline-flex;
     }
 

src/vscode-tree-item/vscode-tree-item.ts

@@ -253,21 +253,24 @@ export class VscodeTreeItem extends VscElement {
   }
 
   private _setCustomState(stateName: string, present: boolean) {
-    const identifiers = stateName.startsWith('--')
-      ? [stateName]
-      : [stateName, `--${stateName}`];
-
-    identifiers.forEach((identifier) => {
-      try {
-        if (present) {
-          this._internals.states.add(identifier);
-        } else {
-          this._internals.states.delete(identifier);
-        }
-      } catch {
-        // Older runtimes that only support :--state throw; ignore silently.
+    if (!this._internals?.states) {
+      return;
+    }
+
+    try {
+      if (present) {
+        this._internals.states.add(stateName);
+      } else {
+        this._internals.states.delete(stateName);
       }
-    });
+    } catch {
+      // https://developer.mozilla.org/en-US/docs/Web/API/CustomStateSet#compatibility_with_dashed-ident_syntax
+      if (present) {
+        this._internals.states.add(`--${stateName}`);
+      } else {
+        this._internals.states.delete(`--${stateName}`);
+      }
+    }
   }
 
   private _getActiveElement(): Element | null {