vsx-registry: update api-compatibility handling

The following commit updates the logic present in `@theia/vsx-registry`
which is used to determine API-compatible extensions. The changes update
the previous assumption that vscode-builtin extensions could not be
downloaded through the extensions-view.

The changes improve the performance overall when dealing with `builtin`
extensions by not updating their information through the registry API
calls which are unecessary. As a result, startup times are improved,
local information such as the extension-editor is quicker, and there are
less API-calls overall which do not burden the registry.

The updated logic behaves in the following way:
- builtins bundled with the application are excluded from fetching their
  compatible version.
- builtins installed through the extensions-view are checked for their
  latest compatible version.

Signed-off-by: vince-fugnitto <vincent.fugnitto@ericsson.com>

packages/vsx-registry/src/browser/vsx-extensions-model.ts

@@ -219,14 +219,18 @@ export class VSXExtensionsModel {
 
     protected async refresh(id: string): Promise<VSXExtension | undefined> {
         try {
+            let extension = this.getExtension(id);
+            if (!this.shouldRefresh(extension)) {
+                return extension;
+            }
             const data = await this.api.getLatestCompatibleExtensionVersion(id);
             if (!data) {
                 return;
             }
             if (data.error) {
                 return this.onDidFailRefresh(id, data.error);
             }
-            const extension = this.setExtension(id);
+            extension = this.setExtension(id);
             extension.update(Object.assign(data, {
                 publisher: data.namespace,
                 downloadUrl: data.files.download,
@@ -241,6 +245,17 @@ export class VSXExtensionsModel {
         }
     }
 
+    /**
+     * Determines if the given extension should be refreshed.
+     * @param extension the extension to refresh.
+     */
+    protected shouldRefresh(extension?: VSXExtension): boolean {
+        if (extension === undefined) {
+            return true;
+        }
+        return !extension.builtin;
+    }
+
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     protected onDidFailRefresh(id: string, error: any): VSXExtension | undefined {
         const cached = this.getExtension(id);

packages/vsx-registry/src/common/vsx-registry-api.ts

@@ -41,11 +41,6 @@ export namespace VSXResponseError {
     }
 }
 
-/**
- * Namespace reserved for vscode builtin extensions.
- */
-const VSCODE_NAMESPACE = 'vscode';
-
 @injectable()
 export class VSXRegistryAPI {
 
@@ -145,10 +140,7 @@ export class VSXRegistryAPI {
         const extensions = await this.getAllVersions(id);
         for (let i = 0; i < extensions.length; i++) {
             const extension: VSXExtensionRaw = extensions[i];
-            // Skip vscode builtin extensions.
-            if (extension.namespace === VSCODE_NAMESPACE) {
-                return extension;
-            } else if (extension.engines && this.isEngineSupported(extension.engines.vscode)) {
+            if (extension.engines && this.isEngineSupported(extension.engines.vscode)) {
                 return extension;
             }
         }