2 files changed, 17 insertions, 1 deletions
diff --git a/cli/tests/unit/test_util.ts b/cli/tests/unit/test_util.ts
index 660e13511..25da7a638 100644
--- a/cli/tests/unit/test_util.ts
+++ b/cli/tests/unit/test_util.ts
@@ -1,6 +1,8 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
 import { assert, assertEquals } from "../../../std/testing/asserts.ts";
+import * as colors from "../../../std/fmt/colors.ts";
+export { colors };
 import { resolve } from "../../../std/path/mod.ts";
 export {
   assert,
@@ -93,7 +95,9 @@ function registerPermCombination(perms: Permissions): void {
 export async function registerUnitTests(): Promise<void> {
   const processPerms = await getProcessPermissions();
 
-  for (const unitTestDefinition of REGISTERED_UNIT_TESTS) {
+  const onlyTests = REGISTERED_UNIT_TESTS.filter(({ only }) => only);
+  const unitTests = onlyTests.length > 0 ? onlyTests : REGISTERED_UNIT_TESTS;
+  for (const unitTestDefinition of unitTests) {
     if (!permissionsMatch(processPerms, unitTestDefinition.perms)) {
       continue;
     }
@@ -126,11 +130,13 @@ interface UnitTestPermissions {
 
 interface UnitTestOptions {
   ignore?: boolean;
+  only?: boolean;
   perms?: UnitTestPermissions;
 }
 
 interface UnitTestDefinition extends Deno.TestDefinition {
   ignore: boolean;
+  only: boolean;
   perms: Permissions;
 }
 
@@ -174,6 +180,7 @@ export function unitTest(
     name,
     fn,
     ignore: !!options.ignore,
+    only: !!options.only,
     perms: normalizedPerms,
   };
 
diff --git a/cli/tests/unit/unit_test_runner.ts b/cli/tests/unit/unit_test_runner.ts
index e3df358d7..38db545c7 100755
--- a/cli/tests/unit/unit_test_runner.ts
+++ b/cli/tests/unit/unit_test_runner.ts
@@ -2,6 +2,8 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import "./unit_tests.ts";
 import {
+  REGISTERED_UNIT_TESTS,
+  colors,
   readLines,
   permissionCombinations,
   Permissions,
@@ -225,6 +227,13 @@ async function masterRunnerMain(
   }
 
   console.log("Unit tests passed");
+
+  if (REGISTERED_UNIT_TESTS.find(({ only }) => only)) {
+    console.error(
+      `\n${colors.red("FAILED")} because the "only" option was used`
+    );
+    Deno.exit(1);
+  }
 }
 
 const HELP = `Unit test runner