Show error message in project panel when manifest can't be built (#1453)

Because we use `swift package describe` to extract metadata about the
package we need the Package.swift to be buildable. If it isn't, create a
header node in the project panel that calls out the fact that the
Package.swift can't be built. Clicking it will take the user to the
Package.swift.

Author: plemarquand

src/commands.ts

@@ -12,6 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+import * as path from "path";
 import * as vscode from "vscode";
 import { WorkspaceContext } from "./WorkspaceContext";
 import { PackageNode } from "./ui/ProjectPanelProvider";
@@ -93,6 +94,7 @@ export enum Commands {
     RUN_ALL_TESTS_PARALLEL = "swift.runAllTestsParallel",
     DEBUG_ALL_TESTS = "swift.debugAllTests",
     COVER_ALL_TESTS = "swift.coverAllTests",
+    OPEN_MANIFEST = "swift.openManifest",
 }
 
 /**
@@ -209,6 +211,10 @@ export function register(ctx: WorkspaceContext): vscode.Disposable[] {
         vscode.commands.registerCommand("swift.openEducationalNote", uri =>
             openEducationalNote(uri)
         ),
+        vscode.commands.registerCommand(Commands.OPEN_MANIFEST, (uri: vscode.Uri) => {
+            const packagePath = path.join(uri.fsPath, "Package.swift");
+            vscode.commands.executeCommand("vscode.open", vscode.Uri.file(packagePath));
+        }),
     ];
 }
 

src/ui/ProjectPanelProvider.ts

@@ -311,12 +311,44 @@ class HeaderNode {
     }
 }
 
+class ErrorNode {
+    constructor(
+        public name: string,
+        private folder: vscode.Uri
+    ) {}
+
+    get path(): string {
+        return "";
+    }
+
+    toTreeItem(): vscode.TreeItem {
+        const item = new vscode.TreeItem(this.name, vscode.TreeItemCollapsibleState.None);
+        item.id = `error-${this.folder.fsPath}`;
+        item.iconPath = new vscode.ThemeIcon("error", new vscode.ThemeColor("errorForeground"));
+        item.contextValue = "error";
+        item.accessibilityInformation = { label: this.name };
+        item.tooltip =
+            "Could not build the Package.swift, fix the error to refresh the project panel";
+
+        item.command = {
+            command: "swift.openManifest",
+            arguments: [this.folder],
+            title: "Open Manifest",
+        };
+        return item;
+    }
+
+    getChildren(): Promise<TreeNode[]> {
+        return Promise.resolve([]);
+    }
+}
+
 /**
  * A node in the Package Dependencies {@link vscode.TreeView TreeView}.
  *
- * Can be either a {@link PackageNode}, {@link FileNode}, {@link TargetNode}, {@link TaskNode} or {@link HeaderNode}.
+ * Can be either a {@link PackageNode}, {@link FileNode}, {@link TargetNode}, {@link TaskNode}, {@link ErrorNode} or {@link HeaderNode}.
  */
-type TreeNode = PackageNode | FileNode | HeaderNode | TaskNode | TargetNode;
+type TreeNode = PackageNode | FileNode | HeaderNode | TaskNode | TargetNode | ErrorNode;
 
 /**
  * A {@link vscode.TreeDataProvider<T> TreeDataProvider} for project dependencies, tasks and commands {@link vscode.TreeView TreeView}.
@@ -328,6 +360,7 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
     private workspaceObserver?: vscode.Disposable;
     private disposables: vscode.Disposable[] = [];
     private activeTasks: Set<string> = new Set();
+    private lastComputedNodes: TreeNode[] = [];
 
     onDidChangeTreeData = this.didChangeTreeDataEmitter.event;
 
@@ -426,6 +459,24 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
             return [];
         }
 
+        if (!element && folderContext.hasResolveErrors) {
+            return [
+                new ErrorNode("Error Parsing Package.swift", folderContext.folder),
+                ...this.lastComputedNodes,
+            ];
+        }
+
+        const nodes = await this.computeChildren(folderContext, element);
+
+        // If we're fetching the root nodes then save them in case we have an error later,
+        // in which case we show the ErrorNode along with the last known good nodes.
+        if (!element) {
+            this.lastComputedNodes = nodes;
+        }
+        return nodes;
+    }
+
+    async computeChildren(folderContext: FolderContext, element?: TreeNode): Promise<TreeNode[]> {
         if (element) {
             return element.getChildren();
         }
@@ -515,7 +566,7 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
         );
     }
 
-    private async tasks(folderContext: FolderContext): Promise<TreeNode[]> {
+    private async tasks(folderContext: FolderContext): Promise<TaskNode[]> {
         const tasks = await vscode.tasks.fetchTasks();
 
         return (

test/integration-tests/ui/ProjectPanelProvider.test.ts

@@ -282,6 +282,15 @@ suite("ProjectPanelProvider Test Suite", function () {
             expect(items.find(n => n.name === "swift-markdown")).to.not.be.undefined;
             expect(items.find(n => n.name === "defaultpackage")).to.not.be.undefined;
         });
+
+        test("Shows an error node when there is a problem compiling Package.swift", async () => {
+            workspaceContext.folders[0].hasResolveErrors = true;
+            workspaceContext.currentFolder = workspaceContext.folders[0];
+            const treeProvider = new ProjectPanelProvider(workspaceContext);
+            const children = await treeProvider.getChildren();
+            const errorNode = children.find(n => n.name === "Error Parsing Package.swift");
+            expect(errorNode).to.not.be.undefined;
+        });
     });
 
     async function getHeaderChildren(headerName: string) {