refactor: Change method signature to Promise (#407)

Co-authored-by: Sheng Chen <sheche@microsoft.com>

Author: xqzlgy2

src/views/containerNode.ts

@@ -20,7 +20,7 @@ export class ContainerNode extends DataNode {
         return this._project.uri && Uri.parse(this._project.uri).fsPath;
     }
 
-    protected loadData(): Thenable<INodeData[]> {
+    protected async loadData(): Promise<INodeData[]> {
         return Jdtls.getPackageData({ kind: NodeKind.Container, projectUri: this._project.uri, path: this.path });
     }
     protected createChildNodeList(): ExplorerNode[] {

src/views/dataNode.ts

@@ -110,7 +110,7 @@ export abstract class DataNode extends ExplorerNode {
 
     protected abstract get iconPath(): string | Uri | { light: string | Uri; dark: string | Uri } | ThemeIcon;
 
-    protected abstract loadData(): Thenable<any[] | undefined>;
+    protected async abstract loadData(): Promise<any[] | undefined>;
 
     protected abstract createChildNodeList(): ExplorerNode[] | undefined;
 }

src/views/dependencyDataProvider.ts

@@ -94,7 +94,7 @@ export class DependencyDataProvider implements TreeDataProvider<ExplorerNode> {
         this._refreshDelayTrigger = _.debounce(this.doRefresh, wait);
     }
 
-    public getTreeItem(element: ExplorerNode): TreeItem | Thenable<TreeItem> {
+    public getTreeItem(element: ExplorerNode): TreeItem | Promise<TreeItem> {
         return element.getTreeItem();
     }
 

src/views/documentSymbolNode.ts

@@ -12,7 +12,7 @@ export class DocumentSymbolNode extends BaseSymbolNode {
         super(symbolInfo, parent);
     }
 
-    public getChildren(): ExplorerNode[] | Thenable<ExplorerNode[]> {
+    public getChildren(): ExplorerNode[] | Promise<ExplorerNode[]> {
         const res: ExplorerNode[] = [];
         if (this.symbolInfo && (<DocumentSymbol>this.symbolInfo).children && (<DocumentSymbol>this.symbolInfo).children.length) {
             (<DocumentSymbol>this.symbolInfo).children.forEach((child) => {

src/views/fileNode.ts

@@ -17,8 +17,8 @@ export class FileNode extends DataNode {
         return false;
     }
 
-    protected loadData(): Thenable<INodeData[] | undefined> {
-        return Promise.resolve(undefined);
+    protected async loadData(): Promise<INodeData[] | undefined> {
+        return undefined;
     }
 
     protected createChildNodeList(): ExplorerNode[] | undefined {

src/views/folderNode.ts

@@ -15,7 +15,7 @@ export class FolderNode extends DataNode {
         super(nodeData, parent);
     }
 
-    protected loadData(): Thenable<INodeData[]> {
+    protected async loadData(): Promise<INodeData[]> {
         return Jdtls.getPackageData({
             kind: NodeKind.Folder,
             projectUri: this._project.uri,

src/views/hierarchicalPackageNode.ts

@@ -56,9 +56,9 @@ export class HierarchicalPackageNode extends PackageNode {
         }
     }
 
-    protected loadData(): Thenable<any[]> {
+    protected async loadData(): Promise<any[]> {
         // Load data only when current node is a package
-        return this.getHierarchicalNodeData().isPackage ? super.loadData() : Promise.resolve([]);
+        return this.getHierarchicalNodeData().isPackage ? super.loadData() : [];
     }
 
     protected createChildNodeList(): ExplorerNode[] {

src/views/packageNode.ts

@@ -16,7 +16,7 @@ export class PackageNode extends DataNode {
         super(nodeData, parent);
     }
 
-    protected loadData(): Thenable<INodeData[]> {
+    protected async loadData(): Promise<INodeData[]> {
         return Jdtls.getPackageData({
             kind: NodeKind.Package,
             projectUri: this._project.nodeData.uri,

src/views/packageRootNode.ts

@@ -21,7 +21,7 @@ export class PackageRootNode extends DataNode {
         super(nodeData, parent);
     }
 
-    protected loadData(): Thenable<INodeData[]> {
+    protected async loadData(): Promise<INodeData[]> {
         return Jdtls.getPackageData({
             kind: NodeKind.PackageRoot,
             projectUri: this._project.nodeData.uri,

src/views/projectNode.ts

@@ -52,7 +52,7 @@ export class ProjectNode extends DataNode {
         return (childNode && paths.length > 0) ? childNode.revealPaths(paths) : childNode;
     }
 
-    protected loadData(): Thenable<INodeData[]> {
+    protected async loadData(): Promise<INodeData[]> {
         let result: INodeData[] = [];
         return Jdtls.getPackageData({ kind: NodeKind.Project, projectUri: this.nodeData.uri }).then((res) => {
             const sourceContainer: IContainerNodeData[] = [];