@@ -136,7 +136,9 @@ export class VsCodeTestController implements TestEventListener, IAmDisposable {
 	}
 
 	public async runTests(debug: boolean, includeCoverage: boolean, request: vs.TestRunRequest, _token: vs.CancellationToken): Promise<void> {
-		await this.discoverer?.ensureSuitesDiscovered();
+		// If we're running all tests, ensure we have discovered them first.
+		if (!request.include)
+			await this.discoverer?.ensureSuitesDiscovered();
 
 		const testsToRun = new Set<vs.TestItem>();
 		const testsToExclude = new Set<vs.TestItem>();
 
@@ -138,10 +138,9 @@ export interface InternalExtensionApi {
 		getLatestData(test: TestItem): TreeNode | undefined,
 		handleDebugSessionEnd(e: DebugSession): void,
 		coverageParser: CoverageParser,
-		discoverer?: { ensureSuitesDiscovered(): Promise<void> }
 	};
 	testCoordinator: TestSessionCoordinator;
-	testDiscoverer: { forceUpdate(uri: Uri): void, ensureSuitesDiscovered(): Promise<void>, testDiscoveryPerformed: Promise<void> | undefined } | undefined,
+	testDiscoverer: { forceUpdate(uri: Uri): void, ensureSuitesDiscovered(): Promise<void>, testDiscoveryPerformed: Promise<void> | undefined },
 	testModel: TestModel;
 	toolingDaemon: DartToolingDaemon | undefined;
 	webClient: WebClient;
 
@@ -3,7 +3,7 @@ import * as fs from "fs";
 import * as path from "path";
 import * as vs from "vscode";
 import { fsPath, tryDeleteFile } from "../../../shared/utils/fs";
-import { activate, checkTreeNodeResults, clearTestTree, defer, delay, getExpectedResults, helloWorldRenameTestFile, helloWorldTestDiscoveryFile, helloWorldTestDiscoveryLargeFile, helloWorldTestFolder, makeTestTextTree, openFile, privateApi, setTestContent, waitForResult } from "../../helpers";
+import { activate, checkTreeNodeResults, clearTestTree, defer, delay, fakeCancellationToken, getExpectedResults, helloWorldRenameTestFile, helloWorldTestDiscoveryFile, helloWorldTestDiscoveryLargeFile, helloWorldTestFolder, makeTestTextTree, openFile, privateApi, setTestContent, waitForResult } from "../../helpers";
 
 describe("dart tests", () => {
 	beforeEach("activate", () => activate());
@@ -84,7 +84,7 @@ hello_world
 	});
 
 	it("does not discover tests in folders excluded by settings", async () => {
-		await privateApi.testController?.discoverer?.ensureSuitesDiscovered();
+		await privateApi.testDiscoverer.ensureSuitesDiscovered();
 		const results = makeTestTextTree();
 		// Ensure results are valid.
 		assert.equal(!!results.find((suite) => suite.includes("basic_test")), true, "basic_test was missing from the test list");
@@ -93,7 +93,7 @@ hello_world
 	});
 
 	it("does not discover tests in folders excluded by analysis_options", async () => {
-		await privateApi.testController?.discoverer?.ensureSuitesDiscovered();
+		await privateApi.testDiscoverer.ensureSuitesDiscovered();
 		const results = makeTestTextTree();
 		// Ensure results are valid.
 		assert.equal(!!results.find((suite) => suite.includes("basic_test")), true);
@@ -102,7 +102,7 @@ hello_world
 	});
 
 	it("handles create/delete of test files on disk", async () => {
-		await privateApi.testController?.discoverer?.ensureSuitesDiscovered();
+		await privateApi.testDiscoverer.ensureSuitesDiscovered();
 
 		const newFilename = "disk_create_test.dart";
 		const newFilePath = path.join(fsPath(helloWorldTestFolder), newFilename);
@@ -127,7 +127,7 @@ void main() => test("test inside ${newFilename}", () {});
 	});
 
 	it("handles renaming of test files on disk", async () => {
-		await privateApi.testController?.discoverer?.ensureSuitesDiscovered();
+		await privateApi.testDiscoverer.ensureSuitesDiscovered();
 
 		const originalFilename = "disk_rename_original_test.dart";
 		const originalFilePath = path.join(fsPath(helloWorldTestFolder), originalFilename);
@@ -146,4 +146,16 @@ void main() => test("test inside ${newFilename}", () {});
 		await waitForResult(() => !makeTestTextTree().some((s) => s.includes(originalFilename)));
 		await waitForResult(() => makeTestTextTree().some((s) => s.includes(newFilename)));
 	});
+
+	it("discovers tests if runTests is called with undefined include", async () => {
+		const request = new vs.TestRunRequest();
+		await privateApi.testController.runTests(false, false, request, fakeCancellationToken);
+		assert.ok(privateApi.testDiscoverer.testDiscoveryPerformed);
+	});
+
+	it("does not discover tests if runTests is called with empty include", async () => {
+		const request = new vs.TestRunRequest([]);
+		await privateApi.testController.runTests(false, false, request, fakeCancellationToken);
+		assert.ok(!privateApi.testDiscoverer.testDiscoveryPerformed);
+	});
 });
Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,9 @@ export class VsCodeTestController implements TestEventListener, IAmDisposable {`
`136`	`136`	`}`
`137`	`137`
`138`	`138`	`public async runTests(debug: boolean, includeCoverage: boolean, request: vs.TestRunRequest, _token: vs.CancellationToken): Promise<void> {`
`139`		`- await this.discoverer?.ensureSuitesDiscovered();`
	`139`	`+ // If we're running all tests, ensure we have discovered them first.`
	`140`	`+ if (!request.include)`
	`141`	`+ await this.discoverer?.ensureSuitesDiscovered();`
`140`	`142`
`141`	`143`	`const testsToRun = new Set<vs.TestItem>();`
`142`	`144`	`const testsToExclude = new Set<vs.TestItem>();`