diff --git a/cmd/pkgserver/ui/static/run_tests.ts b/cmd/pkgserver/ui/static/run_tests.ts
index 71ce2df5..1b8bff83 100644
--- a/cmd/pkgserver/ui/static/run_tests.ts
+++ b/cmd/pkgserver/ui/static/run_tests.ts
@@ -3,5 +3,5 @@
 // provides faster iteration, especially for those acclimated to test-driven
 // development.
 import "./all_tests.js";
-import { StreamReporter, run } from "./test.js";
-run(new StreamReporter({ writeln: console.log }));
+import { StreamReporter, TESTS } from "./test.js";
+TESTS.run(new StreamReporter({ writeln: console.log }));
diff --git a/cmd/pkgserver/ui/static/test.ts b/cmd/pkgserver/ui/static/test.ts
index eec88d82..27553bcf 100644
--- a/cmd/pkgserver/ui/static/test.ts
+++ b/cmd/pkgserver/ui/static/test.ts
@@ -5,11 +5,32 @@ type TestTree = TestGroup | Test;
 type TestGroup = { name: string, children: TestTree[] };
 type Test = { name: string, test: (TestController) => void };
 
-let TESTS: TestGroup[] = [];
+export class TestRegistrar {
+    #suites: TestGroup[];
 
+    constructor() {
+        this.#suites = [];
+    }
+
+    suite(name: string, children: TestTree[]) {
+        checkDuplicates(name, children)
+        this.#suites.push({ name, children });
+    }
+
+    run(reporter: Reporter) {
+        reporter.register(this.#suites);
+        for (const suite of this.#suites) {
+            for (const c of suite.children) runTests(reporter, [suite.name], c);
+        }
+        reporter.finalize();
+    }
+}
+
+export let TESTS = new TestRegistrar();
+
+// Register a suite in the global registrar.
 export function suite(name: string, children: TestTree[]) {
-    checkDuplicates(name, children);
-    TESTS.push({ name, children });
+    TESTS.suite(name, children);
 }
 
 export function context(name: string, children: TestTree[]): TestTree {
@@ -79,14 +100,6 @@ export interface TestResult {
     logs: string[];
 }
 
-export function run(reporter: Reporter) {
-    reporter.register(TESTS);
-    for (const suite of TESTS) {
-        for (const c of suite.children) runTests(reporter, [suite.name], c);
-    }
-    reporter.finalize();
-}
-
 function runTests(reporter: Reporter, parents: string[], node: TestTree) {
     const path = [...parents, node.name];
     if ("children" in node) {
@@ -124,6 +137,30 @@ export interface Reporter {
     finalize(): void;
 }
 
+export class NoOpReporter implements Reporter {
+    suites: TestGroup[];
+    results: ({ path: string[] } & TestResult)[];
+    finalized: boolean;
+
+    constructor() {
+        this.suites = [];
+        this.results = [];
+        this.finalized = false;
+    }
+
+    register(suites: TestGroup[]) {
+        this.suites = suites;
+    }
+
+    update(path: string[], result: TestResult) {
+        this.results.push({ path, ...result });
+    }
+
+    finalize() {
+        this.finalized = true;
+    }
+}
+
 export interface Stream {
     writeln(s: string): void;
 }
diff --git a/cmd/pkgserver/ui/static/test_tests.ts b/cmd/pkgserver/ui/static/test_tests.ts
index 33532f78..fb1627c4 100644
--- a/cmd/pkgserver/ui/static/test_tests.ts
+++ b/cmd/pkgserver/ui/static/test_tests.ts
@@ -1,4 +1,4 @@
-import { context, group, suite, test } from "./test.js";
+import { NoOpReporter, TestRegistrar, context, group, suite, test } from "./test.js";
 
 suite("dog", [
     group("tail", [
@@ -37,4 +37,45 @@ suite("cat", [
     test("likes headpats", (t) => {
         t.log("meow");
     }),
+    test("tester tester", (t) => {
+        const r = new TestRegistrar();
+        r.suite("explod", [
+            test("with yarn", (t) => {
+                t.log("YAY");
+            }),
+        ]);
+        const reporter = new NoOpReporter();
+        r.run(reporter);
+        if (reporter.suites.length !== 1) {
+            t.fatal(`incorrect number of suites registered got=${reporter.suites.length} want=1`);
+        }
+        const suite = reporter.suites[0];
+        if (suite.name !== "explod") {
+            t.error(`suite name incorrect got='${suite.name}' want='explod'`);
+        }
+        if (suite.children.length !== 1) {
+            t.fatal(`incorrect number of suite children got=${suite.children.length} want=1`);
+        }
+        const test_ = suite.children[0];
+        if (test_.name !== "with yarn") {
+            t.error(`incorrect test name got='${test_.name}' want='with yarn'`);
+        }
+        if ("children" in test_) {
+            t.error(`expected leaf node, got group of ${test_.children.length} children`);
+        }
+        if (!reporter.finalized) t.error(`expected reporter to have been finalized`);
+        if (reporter.results.length !== 1) {
+            t.fatal(`incorrect result count got=${reporter.results.length} want=1`);
+        }
+        const result = reporter.results[0];
+        if (!(result.path.length === 2 &&
+              result.path[0] === "explod" &&
+              result.path[1] === "with yarn")) {
+            t.error(`incorrect result path got=${result.path} want=["explod", "with yarn"]`);
+        }
+        if (!result.success) t.error(`expected test to succeed`);
+        if (!(result.logs.length === 1 && result.logs[0] === "YAY")) {
+            t.error(`incorrect result logs got=${result.logs} want=["YAY"]`);
+        }
+    }),
 ]);
diff --git a/cmd/pkgserver/ui/test.html b/cmd/pkgserver/ui/test.html
index 05f14e7f..1b7ab015 100644
--- a/cmd/pkgserver/ui/test.html
+++ b/cmd/pkgserver/ui/test.html
@@ -20,8 +20,8 @@
 
 <script type="module">
     import "./static/all_tests.js";
-    import { DOMReporter, run } from "./static/test.js";
-    run(new DOMReporter());
+    import { DOMReporter, TESTS } from "./static/test.js";
+    TESTS.run(new DOMReporter());
 </script>
 </main>
 </body>