Substitute variables in task "args" (#1544)

- Expand list of supported variables to include some vscode defines that
  make more sense in the context of tasks
- Apply to the list of "args" to "swift" and "swift-plugin" tasks
- Add unit tests to track

Issue: #1150

Author: award999

src/configuration.ts

@@ -473,7 +473,7 @@ const configuration = {
 };
 
 const vsCodeVariableRegex = new RegExp(/\$\{(.+?)\}/g);
-function substituteVariablesInString(val: string): string {
+export function substituteVariablesInString(val: string): string {
     return val.replace(vsCodeVariableRegex, (substring: string, varName: string) =>
         typeof varName === "string" ? computeVscodeVar(varName) || substring : substring
     );
@@ -494,14 +494,24 @@ function computeVscodeVar(varName: string): string | null {
         return vscode.workspace.workspaceFolders?.at(0)?.uri.fsPath ?? "";
     };
 
+    const file = () => vscode.window.activeTextEditor?.document?.uri?.fsPath || "";
+
     // https://code.visualstudio.com/docs/editor/variables-reference
     // Variables to be substituted should be added here.
     const supportedVariables: { [k: string]: () => string } = {
         workspaceFolder,
+        fileWorkspaceFolder: workspaceFolder,
         workspaceFolderBasename: () => path.basename(workspaceFolder()),
         cwd: () => process.cwd(),
         userHome: () => os.homedir(),
         pathSeparator: () => path.sep,
+        file,
+        relativeFile: () => path.relative(workspaceFolder(), file()),
+        relativeFileDirname: () => path.dirname(path.relative(workspaceFolder(), file())),
+        fileBasename: () => path.basename(file()),
+        fileExtname: () => path.extname(file()),
+        fileDirname: () => path.dirname(file()),
+        fileDirnameBasename: () => path.basename(path.dirname(file())),
     };
 
     return varName in supportedVariables ? supportedVariables[varName]() : null;

src/tasks/SwiftPluginTaskProvider.ts

@@ -19,7 +19,10 @@ import { PackagePlugin } from "../SwiftPackage";
 import { swiftRuntimeEnv } from "../utilities/utilities";
 import { SwiftExecution } from "../tasks/SwiftExecution";
 import { resolveTaskCwd } from "../utilities/tasks";
-import configuration, { PluginPermissionConfiguration } from "../configuration";
+import configuration, {
+    PluginPermissionConfiguration,
+    substituteVariablesInString,
+} from "../configuration";
 import { SwiftTask } from "./SwiftTaskProvider";
 import { SwiftToolchain } from "../toolchain/toolchain";
 
@@ -86,7 +89,7 @@ export class SwiftPluginTaskProvider implements vscode.TaskProvider {
             "package",
             ...this.pluginArguments(task.definition as PluginPermissionConfiguration),
             task.definition.command,
-            ...task.definition.args,
+            ...(task.definition.args ?? []).map(substituteVariablesInString),
         ];
         swiftArgs = currentFolder.toolchain.buildFlags.withAdditionalFlags(swiftArgs);
 

src/tasks/SwiftTaskProvider.ts

@@ -16,7 +16,10 @@ import * as vscode from "vscode";
 import { WorkspaceContext } from "../WorkspaceContext";
 import { FolderContext } from "../FolderContext";
 import { Product } from "../SwiftPackage";
-import configuration, { ShowBuildStatusOptions } from "../configuration";
+import configuration, {
+    ShowBuildStatusOptions,
+    substituteVariablesInString,
+} from "../configuration";
 import { swiftRuntimeEnv } from "../utilities/utilities";
 import { Version } from "../utilities/version";
 import { SwiftToolchain } from "../toolchain/toolchain";
@@ -442,7 +445,9 @@ export class SwiftTaskProvider implements vscode.TaskProvider {
             platform = task.definition.macos;
         }
         // get args and cwd values from either platform specific block or base
-        const args = platform?.args ?? task.definition.args;
+        const args = (platform?.args ?? task.definition.args ?? []).map(
+            substituteVariablesInString
+        );
         const env = platform?.env ?? task.definition.env;
         const fullCwd = resolveTaskCwd(task, platform?.cwd ?? task.definition.cwd);
         const fullEnv = {

test/unit-tests/tasks/SwiftPluginTaskProvider.test.ts

@@ -14,6 +14,7 @@
 
 import * as vscode from "vscode";
 import * as assert from "assert";
+import * as os from "os";
 import * as path from "path";
 import { match } from "sinon";
 import { WorkspaceContext } from "../../../src/WorkspaceContext";
@@ -269,5 +270,30 @@ suite("SwiftPluginTaskProvider Unit Test Suite", () => {
                 "my-plugin",
             ]);
         });
+
+        test("substitutes variables", async () => {
+            const taskProvider = new SwiftPluginTaskProvider(instance(workspaceContext));
+            const task = new vscode.Task(
+                {
+                    type: "swift-plugin",
+                    args: ["${cwd}", "${userHome}"],
+                    command: "my-plugin",
+                },
+                workspaceFolder,
+                "MyPlugin",
+                "swift"
+            );
+            const resolvedTask = taskProvider.resolveTask(
+                task,
+                new vscode.CancellationTokenSource().token
+            );
+            const swiftExecution = resolvedTask.execution as SwiftExecution;
+            assert.deepEqual(swiftExecution.args, [
+                "package",
+                "my-plugin",
+                process.cwd(),
+                os.homedir(),
+            ]);
+        });
     });
 });

test/unit-tests/tasks/SwiftTaskProvider.test.ts

@@ -14,6 +14,7 @@
 
 import * as vscode from "vscode";
 import * as assert from "assert";
+import * as os from "os";
 import { match } from "sinon";
 import { WorkspaceContext } from "../../../src/WorkspaceContext";
 import {
@@ -330,6 +331,31 @@ suite("SwiftTaskProvider Unit Test Suite", () => {
             assert.equal(swiftExecution.command, "/path/to/bin/swift");
         });
 
+        test("substitutes variables", () => {
+            const taskProvider = new SwiftTaskProvider(instance(workspaceContext));
+            const task = new vscode.Task(
+                {
+                    type: "swift",
+                    args: ["run", "PackageExe", "--", "${cwd}", "${userHome}"],
+                },
+                workspaceFolder,
+                "run PackageExe",
+                "swift"
+            );
+            const resolvedTask = taskProvider.resolveTask(
+                task,
+                new vscode.CancellationTokenSource().token
+            );
+            const swiftExecution = resolvedTask.execution as SwiftExecution;
+            assert.deepEqual(swiftExecution.args, [
+                "run",
+                "PackageExe",
+                "--",
+                process.cwd(),
+                os.homedir(),
+            ]);
+        });
+
         suite("Platform cwd", () => {
             test("includes macos cwd", () => {
                 platformMock.setValue("darwin");