From e97e2729dca4e0a0236e78379d258715cb3f9e4f Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 22 Apr 2025 16:44:30 +0200
Subject: [PATCH 01/11] Add --no-prefetch cli flag
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

--no-prefetch will directly use `load(...)` instead of
just injecting the script sources which makes it easier to navigate
and investigate profiles.

- Support more complex command line args and flags
- Add --help to cli.js

Bug: 411303884
Change-Id: I43a032342a6da42bfb61ebd9415e62f9d9597ecc
Reviewed-on: https://chromium-review.googlesource.com/c/external/github.com/WebKit/JetStream/+/6468518
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
---
 JetStreamDriver.js | 14 +++++++++++++-
 cli.js             | 48 +++++++++++++++++++++++++++++++++++++++-------
 index.html         |  2 ++
 3 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 77d74c59..da9a5054 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -39,6 +39,7 @@ globalThis.testWorstCaseCountMap ??= new Map();
 globalThis.dumpJSONResults ??= false;
 globalThis.customTestList ??= [];
 globalThis.startDelay ??= undefined;
+globalThis.prefetchResources ??= true;
 
 let shouldReport = false;
 
@@ -52,6 +53,13 @@ function getIntParam(urlParams, key) {
     return value
 }
 
+function getBoolParam(urlParams, key, defaultValue=false) {
+    if (!urlParams.has(key))
+        return defaultValue;
+    const rawValue = urlParams.get(key).toLowerCase()
+    return (rawValue !== "false" && rawValue !== "0")
+ }
+
 if (typeof(URLSearchParams) !== "undefined") {
     const urlParameters = new URLSearchParams(window.location.search);
     shouldReport = urlParameters.has('report') && urlParameters.get('report').toLowerCase() == 'true';
@@ -62,6 +70,7 @@ if (typeof(URLSearchParams) !== "undefined") {
         customTestList = urlParameters.getAll("test");
     globalThis.testIterationCount = getIntParam(urlParameters, "iterationCount");
     globalThis.testWorstCaseCount = getIntParam(urlParameters, "worstCaseCount");
+    globalThis.prefetchResources = getBoolParam(urlParameters, "prefetchResources", true)
 }
 
 // Used for the promise representing the current benchmark run.
@@ -197,8 +206,11 @@ const fileLoader = (function() {
         }
 
         async _loadInternal(url) {
-            if (!isInBrowser)
+            if (!isInBrowser) {
+                if (!globalThis.prefetchResources)
+                    return Promise.resolve(`load("${url}");`);
                 return Promise.resolve(readFile(url));
+            }
 
             let response;
             const tries = 3;
diff --git a/cli.js b/cli.js
index 7a3a5ccb..fac9f0f4 100644
--- a/cli.js
+++ b/cli.js
@@ -23,6 +23,7 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
 */
 
+globalThis.prefetchResources = true;
 const isInBrowser = false;
 console = {
     log: globalThis?.console?.log ?? print,
@@ -33,15 +34,35 @@ const isD8 = typeof Realm !== "undefined";
 if (isD8)
     globalThis.readFile = read;
 const isSpiderMonkey = typeof newGlobal !== "undefined";
-if (isSpiderMonkey) {
+if (isSpiderMonkey)
     globalThis.readFile = readRelativeToScript;
-    globalThis.arguments = scriptArgs;
+
+
+let cliFlags = {};
+let cliArgs = [];
+
+if (typeof arguments != "undefined" && arguments.length > 0) {
+    for (const arg of arguments) {
+        if (arg.startsWith("--")) {
+            const parts = arg.split("=");
+            cliFlags[parts[0]] = parts.slice(1).join("=");
+        } else {
+            cliArgs.push(arg);
+        }
+    }
+}
+
+if (typeof testList === "undefined") {
+    if (cliArgs.length > 0) {
+        testList = cliArgs;
+    } else {
+        testList = undefined;
+    }
 }
 
-if (typeof arguments !== "undefined" && arguments.length > 0)
-    testList = arguments.slice();
-if (typeof testList === "undefined")
-    testList = undefined;
+if ("--no-prefetch" in cliFlags || "--noprefetch" in cliFlags)
+   globalThis.prefetchResources = false
+
 
 if (typeof testIterationCount === "undefined")
     testIterationCount = undefined;
@@ -53,6 +74,20 @@ else
 
 load("./JetStreamDriver.js");
 
+if ("--help" in cliFlags) {
+    print("JetStream Driver Help")
+    print("")
+    print("Options:")
+    print("   --no-prefetch: directly use load('...') for benchmark resources.")
+    print("")
+    print("Available tests:")
+    for (const test of testPlans)
+        print("  ", test.name)
+} else {
+    print("Running tests: " + testList)
+    runJetStream();
+}
+
 async function runJetStream() {
     try {
         await JetStream.initialize();
@@ -63,4 +98,3 @@ async function runJetStream() {
         throw e;
     }
 }
-runJetStream();
diff --git a/index.html b/index.html
index 98992b58..27bc1ecb 100644
--- a/index.html
+++ b/index.html
@@ -36,7 +36,9 @@
     const isInBrowser = true;
     const isD8 = false;
     const isSpiderMonkey = false;
+    globalThis.prefetchResources = true;
     globalThis.allIsGood = true;
+
     window.onerror = function(e) {
         if (e == "Script error.") {
             // This is a workaround for Firefox on iOS which has an uncaught exception from

From 1f4b223d6fdc4ce4b3774ac3bbfc47af2e87404a Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Wed, 23 Apr 2025 18:53:54 +0200
Subject: [PATCH 02/11] skip resources

---
 JetStreamDriver.js | 105 +++++++++++++++++++++++++--------------------
 cli.js             |   1 +
 2 files changed, 60 insertions(+), 46 deletions(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index da9a5054..b7fb0e12 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -57,7 +57,7 @@ function getBoolParam(urlParams, key, defaultValue=false) {
     if (!urlParams.has(key))
         return defaultValue;
     const rawValue = urlParams.get(key).toLowerCase()
-    return (rawValue !== "false" && rawValue !== "0")
+    return !(rawValue === "false" || rawValue === "0")
  }
 
 if (typeof(URLSearchParams) !== "undefined") {
@@ -70,9 +70,12 @@ if (typeof(URLSearchParams) !== "undefined") {
         customTestList = urlParameters.getAll("test");
     globalThis.testIterationCount = getIntParam(urlParameters, "iterationCount");
     globalThis.testWorstCaseCount = getIntParam(urlParameters, "worstCaseCount");
-    globalThis.prefetchResources = getBoolParam(urlParameters, "prefetchResources", true)
+    globalThis.prefetchResources = getBoolParam(urlParameters, "prefetchResources", true);
 }
 
+if (!globalThis.prefetchResources)
+    console.warn("Disabling resource prefetching!", globalThis.prefetchResources)
+
 // Used for the promise representing the current benchmark run.
 this.currentResolve = null;
 this.currentReject = null;
@@ -199,54 +202,56 @@ function uiFriendlyDuration(time)
     return result;
 }
 
-const fileLoader = (function() {
-    class Loader {
-        constructor() {
-            this.requests = new Map;
+class FileLoader {
+    constructor() {
+        this.requests = new Map;
+    }
+
+    async _loadInternal(url) {
+        if (!isInBrowser) {
+            if (!globalThis.prefetchResources)
+                return Promise.resolve(`load("${url}");`);
+            return Promise.resolve(readFile(url));
         }
 
-        async _loadInternal(url) {
-            if (!isInBrowser) {
-                if (!globalThis.prefetchResources)
-                    return Promise.resolve(`load("${url}");`);
-                return Promise.resolve(readFile(url));
-            }
+        if (!globalThis.prefetchResources)
+            return Promise.resolve(`<script src="${url}"></script>"`);
 
-            let response;
-            const tries = 3;
-            while (tries--) {
-                let hasError = false;
-                try {
-                    response = await fetch(url);
-                } catch (e) {
-                    hasError = true;
-                }
-                if (!hasError && response.ok)
-                    break;
-                if (tries)
-                    continue;
-                globalThis.allIsGood = false;
-                throw new Error("Fetch failed");
+        let response;
+        const tries = 3;
+        while (tries--) {
+            let hasError = false;
+            try {
+                response = await fetch(url);
+            } catch (e) {
+                hasError = true;
             }
-            if (url.indexOf(".js") !== -1)
-                return response.text();
-            else if (url.indexOf(".wasm") !== -1)
-                return response.arrayBuffer();
-
-            throw new Error("should not be reached!");
+            if (!hasError && response.ok)
+                break;
+            if (tries)
+                continue;
+            globalThis.allIsGood = false;
+            throw new Error("Fetch failed");
         }
+        if (url.indexOf(".js") !== -1)
+            return response.text();
+        else if (url.indexOf(".wasm") !== -1)
+            return response.arrayBuffer();
 
-        async load(url) {
-            if (this.requests.has(url))
-                return this.requests.get(url);
+        throw new Error("should not be reached!");
+    }
 
-            const promise = this._loadInternal(url);
-            this.requests.set(url, promise);
-            return promise;
-        }
+    async load(url) {
+        if (this.requests.has(url))
+            return this.requests.get(url);
+
+        const promise = this._loadInternal(url);
+        this.requests.set(url, promise);
+        return promise;
     }
-    return new Loader;
-})();
+}
+
+const fileLoader = new FileLoader();
 
 class Driver {
     constructor() {
@@ -295,7 +300,7 @@ class Driver {
             benchmark.updateUIAfterRun();
             console.log(benchmark.name)
 
-            if (isInBrowser) {
+            if (isInBrowser && globalThis.prefetchResources) {
                 const cache = JetStream.blobDataCache;
                 for (const file of benchmark.plan.files) {
                     const blobData = cache[file];
@@ -803,8 +808,12 @@ class Benchmark {
                 addScript(text);
         } else {
             const cache = JetStream.blobDataCache;
-            for (const file of this.plan.files)
-                addScriptWithURL(cache[file].blobURL);
+            for (const file of this.plan.files) {
+                if (globalThis.prefetchResources)
+                    addScriptWithURL(cache[file].blobURL);
+                else
+                    addScriptWithURL(file);
+            }
         }
 
         const promise = new Promise((resolve, reject) => {
@@ -857,6 +866,11 @@ class Benchmark {
     }
 
     async doLoadBlob(resource) {
+        const blobData = JetStream.blobDataCache[resource];
+        if (!globalThis.prefetchResources) {
+            blobData.blobURL = resource; 
+            return blobData;
+        }
         let response;
         let tries = 3;
         while (tries--) {
@@ -873,7 +887,6 @@ class Benchmark {
             throw new Error("Fetch failed");
         }
         const blob = await response.blob();
-        const blobData = JetStream.blobDataCache[resource];
         blobData.blob = blob;
         blobData.blobURL = URL.createObjectURL(blob);
         return blobData;
diff --git a/cli.js b/cli.js
index fac9f0f4..5dba1990 100644
--- a/cli.js
+++ b/cli.js
@@ -27,6 +27,7 @@ globalThis.prefetchResources = true;
 const isInBrowser = false;
 console = {
     log: globalThis?.console?.log ?? print,
+    warn: globalThis?.console?.warn ?? print,
     error: globalThis?.console?.error ?? print,
 }
 

From 0842af58794af80b06be18d84a857e82a76da2da Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Wed, 30 Apr 2025 09:57:09 +0200
Subject: [PATCH 03/11] cleanup

---
 cli.js     | 22 +++++++++++-----------
 index.html |  1 -
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/cli.js b/cli.js
index 5dba1990..a3473ecb 100644
--- a/cli.js
+++ b/cli.js
@@ -75,6 +75,17 @@ else
 
 load("./JetStreamDriver.js");
 
+async function runJetStream() {
+    try {
+        await JetStream.initialize();
+        await JetStream.start();
+    } catch (e) {
+        console.error("JetStream3 failed: " + e);
+        console.error(e.stack);
+        throw e;
+    }
+}
+
 if ("--help" in cliFlags) {
     print("JetStream Driver Help")
     print("")
@@ -88,14 +99,3 @@ if ("--help" in cliFlags) {
     print("Running tests: " + testList)
     runJetStream();
 }
-
-async function runJetStream() {
-    try {
-        await JetStream.initialize();
-        await JetStream.start();
-    } catch (e) {
-        console.error("JetStream3 failed: " + e);
-        console.error(e.stack);
-        throw e;
-    }
-}
diff --git a/index.html b/index.html
index 27bc1ecb..703202dd 100644
--- a/index.html
+++ b/index.html
@@ -38,7 +38,6 @@
     const isSpiderMonkey = false;
     globalThis.prefetchResources = true;
     globalThis.allIsGood = true;
-
     window.onerror = function(e) {
         if (e == "Script error.") {
             // This is a workaround for Firefox on iOS which has an uncaught exception from

From 6c92f778cbf639563b522fa570f5ff13c2adfd55 Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Wed, 30 Jul 2025 16:24:55 +0200
Subject: [PATCH 04/11] cleanup

---
 JetStreamDriver.js | 60 +++++++---------------------------------------
 cli.js             | 14 ++---------
 index.html         |  1 -
 shell-config.js    |  1 +
 4 files changed, 11 insertions(+), 65 deletions(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 1b021778..37ec1458 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -78,7 +78,7 @@ if (typeof(URLSearchParams) !== "undefined") {
         globalThis.testList = getTestListParam(urlParameters, "test");
     globalThis.testIterationCount = getIntParam(urlParameters, "iterationCount");
     globalThis.testWorstCaseCount = getIntParam(urlParameters, "worstCaseCount");
-    globalThis.prefetchResources = getBoolParam(urlParameters, "prefetchResources", true);
+    globalThis.prefetchResources = getBoolParam(urlParameters, "prefetchResources", globalThis.prefetchResources);
 }
 
 if (!globalThis.prefetchResources)
@@ -189,7 +189,7 @@ function uiFriendlyDuration(time) {
 // TODO: Cleanup / remove / merge. This is only used for caching loads in the
 // non-browser setting. In the browser we use exclusively `loadCache`, 
 // `loadBlob`, `doLoadBlob`, `prefetchResourcesForBrowser` etc., see below.
-class FileLoader {
+class ShellFileLoader {
     constructor() {
         this.requests = new Map;
     }
@@ -198,6 +198,8 @@ class FileLoader {
     // share common code.
     load(url) {
         assert(!isInBrowser);
+        if (!globalThis.prefetchResources)
+            return `load("${url}");`
 
         if (this.requests.has(url)) {
             return this.requests.get(url);
@@ -207,52 +209,9 @@ class FileLoader {
         this.requests.set(url, contents);
         return contents;
     }
+};
 
-    async _loadInternal(url) {
-        if (!isInBrowser) {
-            if (!globalThis.prefetchResources)
-                return Promise.resolve(`load("${url}");`);
-            return Promise.resolve(readFile(url));
-        }
-
-        if (!globalThis.prefetchResources)
-            return Promise.resolve(`<script src="${url}"></script>"`);
-
-        let response;
-        const tries = 3;
-        while (tries--) {
-            let hasError = false;
-            try {
-                response = await fetch(url);
-            } catch (e) {
-                hasError = true;
-            }
-            if (!hasError && response.ok)
-                break;
-            if (tries)
-                continue;
-            globalThis.allIsGood = false;
-            throw new Error("Fetch failed");
-        }
-        if (url.indexOf(".js") !== -1)
-            return response.text();
-        else if (url.indexOf(".wasm") !== -1)
-            return response.arrayBuffer();
-
-        throw new Error("should not be reached!");
-    }
-
-    async load(url) {
-        if (this.requests.has(url))
-            return this.requests.get(url);
-
-        const promise = this._loadInternal(url);
-        this.requests.set(url, promise);
-        return promise;
-    }
-}
-
-const fileLoader = new FileLoader();
+const fileLoader = new ShellFileLoader();
 
 class Driver {
     constructor() {
@@ -835,10 +794,7 @@ class Benchmark {
         } else {
             const cache = JetStream.blobDataCache;
             for (const file of this.plan.files) {
-                if (globalThis.prefetchResources)
-                    addScriptWithURL(cache[file].blobURL);
-                else
-                    addScriptWithURL(file);
+                addScriptWithURL(globalThis.prefetchResources ? cache[file].blobURL : file);
             }
         }
 
@@ -894,7 +850,7 @@ class Benchmark {
     async doLoadBlob(resource) {
         const blobData = JetStream.blobDataCache[resource];
         if (!globalThis.prefetchResources) {
-            blobData.blobURL = resource; 
+            blobData.blobURL = resource;
             return blobData;
         }
         let response;
diff --git a/cli.js b/cli.js
index 679f5940..a3279c4e 100644
--- a/cli.js
+++ b/cli.js
@@ -37,15 +37,5 @@ async function runJetStream() {
     }
 }
 
-if ("--help" in cliFlags) {
-    print("JetStream Driver Help")
-    print("")
-    print("Options:")
-    print("   --no-prefetch: directly use load('...') for benchmark resources.")
-    print("")
-    print("Available tests:")
-    for (const test of testPlans)
-        print("  ", test.name)
-} else {
-    runJetStream();
-}
+// FIXME: Add flag for setting prefetch resources
+runJetStream();
diff --git a/index.html b/index.html
index 703202dd..98992b58 100644
--- a/index.html
+++ b/index.html
@@ -36,7 +36,6 @@
     const isInBrowser = true;
     const isD8 = false;
     const isSpiderMonkey = false;
-    globalThis.prefetchResources = true;
     globalThis.allIsGood = true;
     window.onerror = function(e) {
         if (e == "Script error.") {
diff --git a/shell-config.js b/shell-config.js
index c38f4437..3f47eb85 100644
--- a/shell-config.js
+++ b/shell-config.js
@@ -27,6 +27,7 @@ const isInBrowser = false;
 console = {
     log: globalThis?.console?.log ?? print,
     error: globalThis?.console?.error ?? print,
+    warn: globalThis?.console?.warn ?? print,
 }
 
 const isD8 = typeof Realm !== "undefined";

From de526d9d1b8c9c0127857de8c55a48948ed96183 Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Wed, 30 Jul 2025 16:26:03 +0200
Subject: [PATCH 05/11] cleanup

---
 JetStreamDriver.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 37ec1458..0be0554d 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -82,7 +82,7 @@ if (typeof(URLSearchParams) !== "undefined") {
 }
 
 if (!globalThis.prefetchResources)
-    console.warn("Disabling resource prefetching!", globalThis.prefetchResources)
+    console.warn("Disabling resource prefetching!");
 
 // Used for the promise representing the current benchmark run.
 this.currentResolve = null;

From c57ba7c7c19e16635ab363857b38dba31efba322 Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 5 Aug 2025 14:52:56 +0200
Subject: [PATCH 06/11] cleanup and add test

---
 package.json        |  1 +
 tests/run-shell.mjs |  1 +
 tests/run.mjs       | 10 +++++++---
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index efc89908..7760f4b9 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
         "test:firefox": "node tests/run.mjs --browser firefox",
         "test:safari": "node tests/run.mjs --browser safari",
         "test:edge": "node tests/run.mjs --browser edge",
+        "test:shell": "npm run test:v8 && npm run test:jsc && npm run test:spidermonkey",
         "test:v8": "node tests/run-shell.mjs --shell v8",
         "test:jsc": "node tests/run-shell.mjs --shell jsc",
         "test:spidermonkey": "node tests/run-shell.mjs --shell spidermonkey"
diff --git a/tests/run-shell.mjs b/tests/run-shell.mjs
index f31a646b..c2353c0a 100644
--- a/tests/run-shell.mjs
+++ b/tests/run-shell.mjs
@@ -84,6 +84,7 @@ async function runTests() {
     let success = true;
     success &&= await runTest("Run UnitTests", () => sh(shellBinary, UNIT_TEST_PATH));
     success &&= await runCLITest("Run Single Suite", shellBinary, "proxy-mobx");
+    success &&= await runCLITest("Run Tag No Prefetch", shellBinary, "proxy", "--no-prefetch");
     success &&= await runCLITest("Run Disabled Suite", shellBinary, "disabled");
     success &&= await runCLITest("Run Default Suite",  shellBinary);
     if (!success)
diff --git a/tests/run.mjs b/tests/run.mjs
index 6ef609a9..27a71db6 100644
--- a/tests/run.mjs
+++ b/tests/run.mjs
@@ -60,9 +60,10 @@ const server = await serve(PORT);
 async function runTests() {
     let success = true;
     try {
-        success &&= await runTest("Run Single Suite", () => testEnd2End({ test: "proxy-mobx" }));
-        success &&= await runTest("Run Disabled Suite", () => testEnd2End({ tag: "disabled" }));
-        success &&= await runTest("Run Default Suite", () => testEnd2End());
+        success &&= await runEnd2EndTest("Run Single Suite", { test: "proxy-mobx" });
+        success &&= await runEnd2EndTest("Run Tag No Prefetch",  { tag: "proxy", prefetchResources:"false"});
+        success &&= await runEnd2EndTest("Run Disabled Suite", { tag: "disabled" });
+        success &&= await runEnd2EndTest("Run Default Suite");
     } finally {
         server.close();
     }
@@ -70,6 +71,9 @@ async function runTests() {
       process.exit(1);
 }
 
+async function runEnd2EndTest(name, params) {
+    return runTest(name, () => testEnd2End(params));
+}
 
 async function testEnd2End(params) {
     const driver = await new Builder().withCapabilities(capabilities).build();

From fe070cc5ffc73aacf4eef54dfd23e2acb0e1fe0a Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 5 Aug 2025 15:37:46 +0200
Subject: [PATCH 07/11] fix test and runner

---
 JetStreamDriver.js  | 39 +++++++++++++++++++++++----------------
 cli.js              |  2 +-
 tests/run-shell.mjs | 43 +++++++++++++++++++++++++++++++++++++------
 tests/run.mjs       |  2 +-
 4 files changed, 62 insertions(+), 24 deletions(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 932432e5..0ca7c68e 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -97,7 +97,7 @@ function displayCategoryScores() {
 
     let summaryElement = document.getElementById("result-summary");
     for (let [category, scores] of categoryScores)
-        summaryElement.innerHTML += `<p> ${category}: ${uiFriendlyScore(geomean(scores))}</p>`
+        summaryElement.innerHTML += `<p> ${category}: ${uiFriendlyScore(geomeanScore(scores))}</p>`
 
     categoryScores = null;
 }
@@ -147,12 +147,14 @@ function mean(values) {
     return sum / values.length;
 }
 
-function geomean(values) {
+function geomeanScore(values) {
     assert(values instanceof Array);
     let product = 1;
     for (let x of values)
         product *= x;
-    return product ** (1 / values.length);
+    const score = product ** (1 / values.length);
+    assert(score >= 0, `Got invalid score: ${score}`)
+    return score;
 }
 
 function toScore(timeValue) {
@@ -211,7 +213,7 @@ class ShellFileLoader {
     }
 };
 
-const fileLoader = new ShellFileLoader();
+const shellFileLoader = new ShellFileLoader();
 
 class Driver {
     constructor(benchmarks) {
@@ -221,6 +223,7 @@ class Driver {
         // Make benchmark list unique and sort it.
         this.benchmarks = Array.from(new Set(benchmarks));
         this.benchmarks.sort((a, b) => a.plan.name.toLowerCase() < b.plan.name.toLowerCase() ? 1 : -1);
+        assert(this.benchmarks.length, "No benchmarks selected");
         // TODO: Cleanup / remove / merge `blobDataCache` and `loadCache` vs.
         // the global `fileLoader` cache.
         this.blobDataCache = { };
@@ -280,8 +283,10 @@ class Driver {
         }
 
         const allScores = [];
-        for (const benchmark of this.benchmarks)
-            allScores.push(benchmark.score);
+        for (const benchmark of this.benchmarks) {
+            const score = benchmark.score;
+            allScores.push(score);
+        }
 
         categoryScores = new Map;
         for (const benchmark of this.benchmarks) {
@@ -292,23 +297,26 @@ class Driver {
         for (const benchmark of this.benchmarks) {
             for (let [category, value] of Object.entries(benchmark.subScores())) {
                 const arr = categoryScores.get(category);
+                assert(value > 0, `Invalid ${benchmark.name} ${category}: ${value}`);
                 arr.push(value);
             }
         }
 
+        const totalScore = geomeanScore(allScores);
+
         if (isInBrowser) {
-            summaryElement.classList.add('done');
-            summaryElement.innerHTML = `<div class="score">${uiFriendlyScore(geomean(allScores))}</div><label>Score</label>`;
+            summaryElement.classList.add("done");
+            summaryElement.innerHTML = `<div class="score">${uiFriendlyScore(totalScore)}</div><label>Score</label>`;
             summaryElement.onclick = displayCategoryScores;
             if (showScoreDetails)
                 displayCategoryScores();
-            statusElement.innerHTML = '';
+            statusElement.innerHTML = "";
         } else if (!dumpJSONResults) {
             console.log("\n");
             for (let [category, scores] of categoryScores)
-                console.log(`${category}: ${uiFriendlyScore(geomean(scores))}`);
+                console.log(`${category}: ${uiFriendlyScore(geomeanScore(scores))}`);
 
-            console.log("\nTotal Score: ", uiFriendlyScore(geomean(allScores)), "\n");
+            console.log("\nTotal Score: ", uiFriendlyScore(totalScore), "\n");
         }
 
         this.reportScoreToRunBenchmarkRunner();
@@ -653,7 +661,7 @@ class Benchmark {
 
     get score() {
         const subScores = Object.values(this.subScores());
-        return geomean(subScores);
+        return geomeanScore(subScores);
     }
 
     subScores() {
@@ -978,7 +986,7 @@ class Benchmark {
         assert(!isInBrowser);
 
         assert(this.scripts === null, "This initialization should be called only once.");
-        this.scripts = this.plan.files.map(file => fileLoader.load(file));
+        this.scripts = this.plan.files.map(file => shellFileLoader.load(file));
 
         assert(this.preloads === null, "This initialization should be called only once.");
         this.preloads = Object.entries(this.plan.preload ?? {});
@@ -2399,8 +2407,7 @@ for (const benchmark of BENCHMARKS) {
 }
 
 
-function processTestList(testList)
-{
+function processTestList(testList) {
     let benchmarkNames = [];
     let benchmarks = [];
 
@@ -2412,7 +2419,7 @@ function processTestList(testList)
     for (let name of benchmarkNames) {
         name = name.toLowerCase();
         if (benchmarksByTag.has(name))
-            benchmarks.concat(findBenchmarksByTag(name));
+            benchmarks = benchmarks.concat(findBenchmarksByTag(name));
         else
             benchmarks.push(findBenchmarkByName(name));
     }
diff --git a/cli.js b/cli.js
index b5c467f0..b670d21e 100644
--- a/cli.js
+++ b/cli.js
@@ -56,7 +56,7 @@ if (typeof runMode !== "undefined" && runMode == "RAMification")
     globalThis.RAMification = true;
 if ("--ramification" in cliFlags)
     globalThis.RAMification = true;
-if ("--no-prefetch:" in cliFlags)
+if ("--no-prefetch" in cliFlags)
     globalThis.prefetchResources = false;
 if (cliArgs.length)
     globalThis.testList = cliArgs;
diff --git a/tests/run-shell.mjs b/tests/run-shell.mjs
index c2353c0a..c9343860 100644
--- a/tests/run-shell.mjs
+++ b/tests/run-shell.mjs
@@ -1,7 +1,7 @@
 #! /usr/bin/env node
 
 import commandLineArgs from "command-line-args";
-import { spawnSync } from  "child_process";
+import { spawnSync, spawn } from  "child_process";
 import { fileURLToPath } from "url";
 import { styleText } from "node:util";
 import * as path from "path";
@@ -59,7 +59,7 @@ const SPAWN_OPTIONS =  {
   stdio: ["inherit", "inherit", "inherit"]
 };
 
-function sh(binary, ...args) {
+async function sh(binary, ...args) {
   const cmd = `${binary} ${args.join(" ")}`;
   if (GITHUB_ACTIONS_OUTPUT) {
     core.startGroup(binary);
@@ -68,17 +68,42 @@ function sh(binary, ...args) {
     console.log(styleText("blue", cmd));
   }
   try {
-    const result = spawnSync(binary, args, SPAWN_OPTIONS);
+    const result = await sp(binary, args, SPAWN_OPTIONS);
     if (result.status || result.error) {
       logError(result.error);
       throw new Error(`Shell CMD failed: ${binary} ${args.join(" ")}`);
     }
+    return result;
   } finally {
     if (GITHUB_ACTIONS_OUTPUT)
       core.endGroup();
   }
 }
 
+async function sp(binary, args) {
+  const childProcess = spawn(binary, args);
+  childProcess.stdout.pipe(process.stdout);
+  return new Promise((resolve, reject) => {
+    childProcess.stdoutString = "";
+    childProcess.stdio[1].on("data", (data) => {
+      childProcess.stdoutString += data.toString();
+    });
+    childProcess.on('close', (code) => {
+      if (code === 0) {
+        resolve(childProcess);
+      } else {
+        // Reject the Promise with an Error on failure
+        const error = new Error(`Command failed with exit code ${code}: ${binary} ${args.join(" ")}`);
+        error.process = childProcess;
+        error.stdout = childProcess.stdoutString;
+        error.exitCode = code;
+        reject(error);
+      }
+    });
+    childProcess.on('error', reject);
+  })
+}
+
 async function runTests() {
     const shellBinary = await logGroup(`Installing JavaScript Shell: ${SHELL_NAME}`, testSetup);
     let success = true;
@@ -112,8 +137,8 @@ function jsvuOSName() {
 
 const DEFAULT_JSC_LOCATION = "/System/Library/Frameworks/JavaScriptCore.framework/Versions/Current/Helpers/jsc"
 
-function testSetup() {
-    sh("jsvu", `--engines=${SHELL_NAME}`, `--os=${jsvuOSName()}`);
+async function testSetup() {
+    await sh("jsvu", `--engines=${SHELL_NAME}`, `--os=${jsvuOSName()}`);
     let shellBinary = path.join(os.homedir(), ".jsvu/bin", SHELL_NAME);
     if (!fs.existsSync(shellBinary) && SHELL_NAME == "javascriptcore")
       shellBinary = DEFAULT_JSC_LOCATION;
@@ -124,7 +149,13 @@ function testSetup() {
 }
 
 function runCLITest(name, shellBinary, ...args) {
-  return runTest(name, () => sh(shellBinary, ...convertCliArgs(CLI_PATH, ...args)));
+  return runTest(name, () => runShell(shellBinary, ...convertCliArgs(CLI_PATH, ...args)));
+}
+
+async function runShell(shellBinary, ...args) {
+  const result = await sh(shellBinary, ...args);
+  if (result.stdoutString.includes("JetStream3 failed"))
+    throw new Error("test failed")
 }
 
 setImmediate(runTests);
diff --git a/tests/run.mjs b/tests/run.mjs
index 6bdfcf18..0b9f5959 100644
--- a/tests/run.mjs
+++ b/tests/run.mjs
@@ -61,7 +61,7 @@ async function runTests() {
     let success = true;
     try {
         success &&= await runEnd2EndTest("Run Single Suite", { test: "proxy-mobx" });
-        success &&= await runEnd2EndTest("Run Tag No Prefetch",  { tag: "proxy", prefetchResources:"false"});
+        success &&= await runEnd2EndTest("Run Tag No Prefetch",  { tag: "proxy", prefetchResources: "false" });
         success &&= await runEnd2EndTest("Run Disabled Suite", { tag: "disabled" });
         success &&= await runEnd2EndTest("Run Default Suite");
     } finally {

From 0a1a7de40b7e964b95459b9d544f2c3070a2460b Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 5 Aug 2025 15:40:40 +0200
Subject: [PATCH 08/11] improve assertions

---
 JetStreamDriver.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 0ca7c68e..8685eaa8 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -153,6 +153,7 @@ function geomeanScore(values) {
     for (let x of values)
         product *= x;
     const score = product ** (1 / values.length);
+    // Allow 0 for uninitialized subScores().
     assert(score >= 0, `Got invalid score: ${score}`)
     return score;
 }
@@ -303,6 +304,7 @@ class Driver {
         }
 
         const totalScore = geomeanScore(allScores);
+        assert(totalScore > 0, `Invalid total score: ${totalScore}`);
 
         if (isInBrowser) {
             summaryElement.classList.add("done");

From 14c75440600dad798962fbf136b815a7e704db23 Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 5 Aug 2025 15:49:10 +0200
Subject: [PATCH 09/11] remove unused spawnSync import

---
 tests/run-shell.mjs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/run-shell.mjs b/tests/run-shell.mjs
index c9343860..1c732755 100644
--- a/tests/run-shell.mjs
+++ b/tests/run-shell.mjs
@@ -1,7 +1,7 @@
 #! /usr/bin/env node
 
 import commandLineArgs from "command-line-args";
-import { spawnSync, spawn } from  "child_process";
+import { spawn } from  "child_process";
 import { fileURLToPath } from "url";
 import { styleText } from "node:util";
 import * as path from "path";

From d9236738ed82a61394a4e506890a67b87091d16e Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Tue, 5 Aug 2025 15:50:05 +0200
Subject: [PATCH 10/11] rename

---
 tests/run-shell.mjs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/run-shell.mjs b/tests/run-shell.mjs
index 1c732755..1b626a7d 100644
--- a/tests/run-shell.mjs
+++ b/tests/run-shell.mjs
@@ -68,7 +68,7 @@ async function sh(binary, ...args) {
     console.log(styleText("blue", cmd));
   }
   try {
-    const result = await sp(binary, args, SPAWN_OPTIONS);
+    const result = await spawnCaptureStdout(binary, args, SPAWN_OPTIONS);
     if (result.status || result.error) {
       logError(result.error);
       throw new Error(`Shell CMD failed: ${binary} ${args.join(" ")}`);
@@ -80,7 +80,7 @@ async function sh(binary, ...args) {
   }
 }
 
-async function sp(binary, args) {
+async function spawnCaptureStdout(binary, args) {
   const childProcess = spawn(binary, args);
   childProcess.stdout.pipe(process.stdout);
   return new Promise((resolve, reject) => {

From c82202ae282e7d1ec4b6853f84c4656f916ea2c7 Mon Sep 17 00:00:00 2001
From: Camillo Bruni <cbruni@chromium.org>
Date: Wed, 6 Aug 2025 11:26:57 +0200
Subject: [PATCH 11/11] re-add assertion

---
 JetStreamDriver.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index b6aa00ae..76cf9861 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -286,6 +286,7 @@ class Driver {
         const allScores = [];
         for (const benchmark of this.benchmarks) {
             const score = benchmark.score;
+            assert(score > 0, `Invalid ${benchmark.name} score: ${score}`);
             allScores.push(score);
         }
 
@@ -298,7 +299,7 @@ class Driver {
         for (const benchmark of this.benchmarks) {
             for (let [category, value] of Object.entries(benchmark.subScores())) {
                 const arr = categoryScores.get(category);
-                assert(value > 0, `Invalid ${benchmark.name} ${category}: ${value}`);
+                assert(value > 0, `Invalid ${benchmark.name} ${category} score: ${value}`);
                 arr.push(value);
             }
         }