debug: smarter scope id computation so expansion state is more preser…

…ved. Also if all collapsed, expand first non expensive scope

fixes #93230

src/vs/workbench/contrib/debug/browser/variablesView.ts

@@ -80,8 +80,11 @@ export class VariablesView extends ViewPane {
 				if (stackFrame) {
 					const scopes = await stackFrame.getScopes();
 					// Expand the first scope if it is not expensive and if there is no expansion state (all are collapsed)
-					if (scopes.every(s => this.tree.getNode(s).collapsed) && scopes.length > 0 && !scopes[0].expensive) {
-						this.tree.expand(scopes[0]);
+					if (scopes.every(s => this.tree.getNode(s).collapsed) && scopes.length > 0) {
+						const toExpand = scopes.filter(s => !s.expensive).shift();
+						if (toExpand) {
+							this.tree.expand(toExpand);
+						}
 					}
 				}
 

src/vs/workbench/contrib/debug/common/debugModel.ts

@@ -305,9 +305,19 @@ export class StackFrame implements IStackFrame {
 	getScopes(): Promise<IScope[]> {
 		if (!this.scopes) {
 			this.scopes = this.thread.session.scopes(this.frameId, this.thread.threadId).then(response => {
-				return response && response.body && response.body.scopes ?
-					response.body.scopes.map((rs, index) => new Scope(this, index, rs.name, rs.variablesReference, rs.expensive, rs.namedVariables, rs.indexedVariables,
-						rs.line && rs.column && rs.endLine && rs.endColumn ? new Range(rs.line, rs.column, rs.endLine, rs.endColumn) : undefined)) : [];
+				if (!response || !response.body || !response.body.scopes) {
+					return [];
+				}
+
+				const scopeNameIndexes = new Map<string, number>();
+				return response.body.scopes.map(rs => {
+					const previousIndex = scopeNameIndexes.get(rs.name);
+					const index = typeof previousIndex === 'number' ? previousIndex + 1 : 0;
+					scopeNameIndexes.set(rs.name, index);
+					return new Scope(this, index, rs.name, rs.variablesReference, rs.expensive, rs.namedVariables, rs.indexedVariables,
+						rs.line && rs.column && rs.endLine && rs.endColumn ? new Range(rs.line, rs.column, rs.endLine, rs.endColumn) : undefined);
+
+				});
 			}, err => [new ErrorScope(this, 0, err.message)]);
 		}