Show files generated by build plugins under Target in Project Panel

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - Show revision hash or local/editing keyword in project panel dependency descriptions ([#1667](https://github.com/swiftlang/vscode-swift/pull/1667))
+- Show files generated by build plugins under Target in Project Panel ([#1592](https://github.com/swiftlang/vscode-swift/pull/1592))
 
 ## 2.6.2 - 2025-07-02
 

assets/test/targets/Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.6
+// swift-tools-version: 5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -25,17 +25,28 @@ let package = Package(
     ],
     targets: [
         .target(
-            name: "LibraryTarget"
+            name: "LibraryTarget",
+            plugins: [
+                .plugin(name: "BuildToolPlugin")
+            ]
         ),
         .executableTarget(
             name: "ExecutableTarget"
         ),
+        .executableTarget(
+            name: "BuildToolExecutableTarget"
+        ),
         .plugin(
             name: "PluginTarget",
             capability: .command(
                 intent: .custom(verb: "testing", description: "A plugin for testing plugins")
             )
         ),
+        .plugin(
+            name: "BuildToolPlugin",
+            capability: .buildTool(),
+            dependencies: ["BuildToolExecutableTarget"]
+        ),
         .testTarget(
             name: "TargetsTests",
             dependencies: ["LibraryTarget"]

assets/test/targets/Plugins/BuildToolPlugin/BuildToolPlugin.swift

@@ -0,0 +1,48 @@
+import PackagePlugin
+import Foundation
+
+@main
+struct SimpleBuildToolPlugin: BuildToolPlugin {
+    func createBuildCommands(context: PluginContext, target: Target) async throws -> [Command] {
+        guard let sourceFiles = target.sourceModule?.sourceFiles else { return [] }
+
+        #if os(Windows)
+        return []
+        #endif
+
+        let generatorTool = try context.tool(named: "BuildToolExecutableTarget")
+
+        // Construct a build command for each source file with a particular suffix.
+        return sourceFiles.map(\.path).compactMap {
+            createBuildCommand(
+                for: $0,
+                in: context.pluginWorkDirectory,
+                with: generatorTool.path
+            )
+        }
+    }
+
+    /// Calls a build tool that transforms JSON files into Swift files.
+    func createBuildCommand(for inputPath: Path, in outputDirectoryPath: Path, with generatorToolPath: Path) -> Command? {
+        let inputURL = URL(fileURLWithPath: inputPath.string)
+        let outputDirectoryURL = URL(fileURLWithPath: outputDirectoryPath.string)
+
+        // Skip any file that doesn't have the extension we're looking for (replace this with the actual one).
+        guard inputURL.pathExtension == "json" else { return .none }
+
+        // Produces .swift files in the same directory structure as the input JSON files appear in the target.
+        let components = inputURL.absoluteString.split(separator: "LibraryTarget", omittingEmptySubsequences: false).map(String.init)
+        let inputName = inputURL.lastPathComponent
+        let outputDir = outputDirectoryURL.appendingPathComponent(components[1]).deletingLastPathComponent()
+        let outputName = inputURL.deletingPathExtension().lastPathComponent + ".swift"
+        let outputURL = outputDir.appendingPathComponent(outputName)
+
+        return .buildCommand(
+            displayName: "Generating \(outputName) from \(inputName)",
+            executable: generatorToolPath,
+            arguments: ["\(inputPath)", "\(outputURL.path)"],
+            inputFiles: [inputPath],
+            outputFiles: [Path(outputURL.path)]
+        )
+    }
+}

assets/test/targets/Sources/BuildToolExecutableTarget/BuildToolExecutableTarget.swift

@@ -0,0 +1,45 @@
+#if !os(Windows)
+import Foundation
+
+@main
+struct CodeGenerator {
+    static func main() async throws {
+        // Use swift-argument-parser or just CommandLine, here we just imply that 2 paths are passed in: input and output
+        guard CommandLine.arguments.count == 3 else {
+            throw CodeGeneratorError.invalidArguments
+        }
+        // arguments[0] is the path to this command line tool
+        guard let input = URL(string: "file://\(CommandLine.arguments[1])"), let output = URL(string: "file://\(CommandLine.arguments[2])") else {
+            return
+        }
+        let jsonData = try Data(contentsOf: input)
+        let enumFormat = try JSONDecoder().decode(JSONFormat.self, from: jsonData)
+
+        let code = """
+        enum \(enumFormat.name): CaseIterable {
+        \t\(enumFormat.cases.map({ "case \($0)" }).joined(separator: "\n\t"))
+        }
+        """
+        guard let data = code.data(using: .utf8) else {
+            throw CodeGeneratorError.invalidData
+        }
+        try data.write(to: output, options: .atomic)
+    }
+}
+
+struct JSONFormat: Decodable {
+    let name: String
+    let cases: [String]
+}
+
+enum CodeGeneratorError: Error {
+    case invalidArguments
+    case invalidData
+}
+#else
+@main
+struct DummyMain {
+    static func main() {
+    }
+}
+#endif

assets/test/targets/Sources/LibraryTarget/Bar/Baz.json

@@ -0,0 +1,8 @@
+{
+    "name": "Baz",
+    "cases": [
+        "bar",
+        "baz",
+        "bbb"
+    ]
+}

assets/test/targets/Sources/LibraryTarget/Foo.json

@@ -0,0 +1,8 @@
+{
+    "name": "Foo",
+    "cases": [
+        "bar",
+        "baz",
+        "qux"
+    ]
+}

scripts/package.ts

@@ -34,8 +34,13 @@ main(async () => {
 
     // Update version in CHANGELOG
     await updateChangelog(versionString);
+
     // Use VSCE to package the extension
-    await exec("npx", ["vsce", "package"], {
+    // Note: There are no sendgrid secrets in the extension. `--allow-package-secrets` works around a false positive
+    // where the symbol `SG.MessageTransports.is` can appear in the dist.js if we're unlucky enough
+    // to have `SG` as the minified name of a namespace. Here is the rule we sometimes mistakenly match:
+    // https://github.com/secretlint/secretlint/blob/5706ac4942f098b845570541903472641d4ae914/packages/%40secretlint/secretlint-rule-sendgrid/src/index.ts#L35
+    await exec("npx", ["vsce", "package", "--allow-package-secrets", "sendgrid"], {
         cwd: rootDirectory,
     });
 });

src/ui/ProjectPanelProvider.ts

@@ -24,6 +24,8 @@ import { FolderContext } from "../FolderContext";
 import { getPlatformConfig, resolveTaskCwd } from "../utilities/tasks";
 import { SwiftTask, TaskPlatformSpecificConfig } from "../tasks/SwiftTaskProvider";
 import { convertPathToPattern, glob } from "fast-glob";
+import { Version } from "../utilities/version";
+import { existsSync } from "fs";
 
 const LOADING_ICON = "loading~spin";
 
@@ -282,9 +284,13 @@ function snippetTaskName(name: string): string {
 }
 
 class TargetNode {
+    private newPluginLayoutVersion = new Version(6, 0, 0);
+
     constructor(
         public target: Target,
-        private activeTasks: Set<string>
+        private folder: FolderContext,
+        private activeTasks: Set<string>,
+        private fs?: (folder: string) => Promise<string[]>
     ) {}
 
     get name(): string {
@@ -355,7 +361,41 @@ class TargetNode {
     }
 
     getChildren(): TreeNode[] {
-        return [];
+        return this.buildPluginOutputs(this.folder.toolchain.swiftVersion);
+    }
+
+    private buildToolGlobPattern(version: Version): string {
+        const base = this.folder.folder.fsPath.replace(/\\/g, "/");
+        if (version.isGreaterThanOrEqual(this.newPluginLayoutVersion)) {
+            return `${base}/.build/plugins/outputs/*/${this.target.name}/*/*/**`;
+        } else {
+            return `${base}/.build/plugins/outputs/*/${this.target.name}/*/**`;
+        }
+    }
+
+    private buildPluginOutputs(version: Version): TreeNode[] {
+        // Files in the `outputs` directory follow the pattern:
+        // .build/plugins/outputs/buildtoolplugin/<target-name>/destination/<build-tool-plugin-name>/*
+        // This glob will capture all the files in the outputs directory for this target.
+        const pattern = this.buildToolGlobPattern(version);
+        const base = this.folder.folder.fsPath.replace(/\\/g, "/");
+        const depth = version.isGreaterThanOrEqual(this.newPluginLayoutVersion) ? 4 : 3;
+        const matches = glob.sync(pattern, { onlyFiles: false, cwd: base, deep: depth });
+        return matches.map(filePath => {
+            const pluginName = path.basename(filePath);
+            return new HeaderNode(
+                `${this.target.name}-${pluginName}`,
+                `${pluginName} - Generated Files`,
+                "debug-disconnect",
+                () =>
+                    getChildren(
+                        filePath,
+                        excludedFilesForProjectPanelExplorer(),
+                        this.target.path,
+                        this.fs
+                    )
+            );
+        });
     }
 }
 
@@ -435,6 +475,8 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
     private disposables: vscode.Disposable[] = [];
     private activeTasks: Set<string> = new Set();
     private lastComputedNodes: TreeNode[] = [];
+    private buildPluginOutputWatcher?: vscode.FileSystemWatcher;
+    private buildPluginFolderWatcher?: vscode.Disposable;
 
     onDidChangeTreeData = this.didChangeTreeDataEmitter.event;
 
@@ -515,6 +557,7 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
                         if (!folder) {
                             return;
                         }
+                        this.watchBuildPluginOutputs(folder);
                         treeView.title = `Swift Project (${folder.name})`;
                         this.didChangeTreeDataEmitter.fire();
                         break;
@@ -537,6 +580,33 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
         );
     }
 
+    watchBuildPluginOutputs(folderContext: FolderContext) {
+        if (this.buildPluginOutputWatcher) {
+            this.buildPluginOutputWatcher.dispose();
+        }
+        if (this.buildPluginFolderWatcher) {
+            this.buildPluginFolderWatcher.dispose();
+        }
+
+        const fire = () => this.didChangeTreeDataEmitter.fire();
+        const buildPath = path.join(folderContext.folder.fsPath, ".build/plugins/outputs");
+        this.buildPluginFolderWatcher = watchForFolder(
+            buildPath,
+            () => {
+                this.buildPluginOutputWatcher = vscode.workspace.createFileSystemWatcher(
+                    new vscode.RelativePattern(buildPath, "{*,*/*}")
+                );
+                this.buildPluginOutputWatcher.onDidCreate(fire);
+                this.buildPluginOutputWatcher.onDidDelete(fire);
+                this.buildPluginOutputWatcher.onDidChange(fire);
+            },
+            () => {
+                this.buildPluginOutputWatcher?.dispose();
+                fire();
+            }
+        );
+    }
+
     getTreeItem(element: TreeNode): vscode.TreeItem {
         return element.toTreeItem();
     }
@@ -553,7 +623,6 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
                 ...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,
@@ -649,7 +718,7 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
         // Snipepts are shown under the Snippets header
         return targets
             .filter(target => target.type !== "snippet")
-            .map(target => new TargetNode(target, this.activeTasks))
+            .map(target => new TargetNode(target, folderContext, this.activeTasks))
             .sort((a, b) => targetSort(a).localeCompare(targetSort(b)));
     }
 
@@ -705,7 +774,7 @@ export class ProjectPanelProvider implements vscode.TreeDataProvider<TreeNode> {
         const targets = await folderContext.swiftPackage.targets;
         return targets
             .filter(target => target.type === "snippet")
-            .flatMap(target => new TargetNode(target, this.activeTasks))
+            .flatMap(target => new TargetNode(target, folderContext, this.activeTasks))
             .sort((a, b) => a.name.localeCompare(b.name));
     }
 }
@@ -757,3 +826,35 @@ class TaskPoller implements vscode.Disposable {
         }
     }
 }
+
+/**
+ * Polls for the existence of a folder at the given path every 2.5 seconds.
+ * Notifies via the provided callbacks when the folder becomes available or is deleted.
+ */
+function watchForFolder(
+    folderPath: string,
+    onAvailable: () => void,
+    onDeleted: () => void
+): vscode.Disposable {
+    const POLL_INTERVAL = 2500;
+    let folderExists = existsSync(folderPath);
+
+    if (folderExists) {
+        onAvailable();
+    }
+
+    const interval = setInterval(() => {
+        const nowExists = existsSync(folderPath);
+        if (nowExists && !folderExists) {
+            folderExists = true;
+            onAvailable();
+        } else if (!nowExists && folderExists) {
+            folderExists = false;
+            onDeleted();
+        }
+    }, POLL_INTERVAL);
+
+    return {
+        dispose: () => clearInterval(interval),
+    };
+}