One more chance...

Author: shai-almog

Ports/JavaScriptPort/STATUS.md

@@ -5,6 +5,27 @@ JavaScript Port Status (ParparVM)
 
 Last updated: 2026-04-11
 
+Latest Investigation Snapshot (this round)
+------------------------------------------
+
+- Input artifacts analyzed:
+  - `~/Downloads/job-logs.txt`
+  - `~/Downloads/javascript-ui-tests/browser.log`
+- Confirmed in that artifact set:
+  - Suite completes (`CN1SS:SUITE:FINISHED`) and 32 named streams decode.
+  - Most PNGs are still identical/white (`canvasSig=7263bb45` repeated).
+  - Screenshot helper repeatedly falls back due:
+    - `PARPAR:DIAG:FALLBACK:cn1ssEmitCurrentFormScreenshotDom:originalInvokeErr=Error: Missing JS member get for host receiver`
+- New code changes in workspace (not CI-validated yet):
+  1. Host/runtime JSO bridge now supports array-like indexed fallback for `get(index)`/`set(index,value)` when no callable member exists.
+  2. Host bridge attempts to avoid per-pixel host RPC by cloning typed-array payloads.
+  3. Host bridge has explicit `getter:data` fast-return clone path.
+  4. BaseTest on-show lambda shim now guards missing `target.__classDef` by resolving class metadata from `target.__class`.
+  5. Screenshot fallback now logs short `originalInvokeStack` for first-failure localization.
+- Important caveat from local replay:
+  - Replaying patched runtime against the previously archived CI zip can regress to timeout and show `originalInvokeErr=Cannot read properties of null (reading '__classDef')` during per-test screenshot emission.
+  - This indicates the first blocker has shifted from missing host `.get` to a null receiver/class-init path in translated screenshot execution.
+
 Current State
 -------------
 
@@ -163,10 +184,45 @@ What Was Fixed In This Pass
    - Expected effect:
      - Restore named screenshot stream emission (`CN1SS:<test>`) instead of collapsing to `default`-only stream.
 
+14. Added JSO bridge indexed-access compatibility for array-like receivers.
+   - Files:
+     - `vm/ByteCodeTranslator/src/javascript/browser_bridge.js`
+     - `vm/ByteCodeTranslator/src/javascript/parparvm_runtime.js`
+   - Changes:
+     - If a bridged `method` call has member `get`/`set` and receiver is array-like (`length`), map to indexed element access when no callable JS member exists.
+   - Motivation:
+     - Fixes deterministic screenshot-path failure:
+       - `Missing JS member get for host receiver`
+     - Seen when translated code accesses pixel buffers via `get(index)`.
+
+15. Added host bridge typed-array transfer fast paths.
+   - File:
+     - `vm/ByteCodeTranslator/src/javascript/browser_bridge.js`
+   - Changes:
+     - `hostResult()` now clones/returns typed-array and `ArrayBuffer` values directly instead of always creating host refs.
+     - Added explicit `getter:data` direct-clone return path in `__cn1_jso_bridge__`.
+   - Motivation:
+     - Prevents pathological per-element host RPC loops during pixel-buffer reads.
+   - Status:
+     - Local replay indicates this removes the old `Missing JS member get...` failure, but uncovers a later null `__classDef` path that still needs repair.
+
+16. Hardened BaseTest on-show lambda shim for missing class definition.
+   - File:
+     - `Ports/JavaScriptPort/src/main/webapp/port.js`
+   - Changes:
+     - `target.__classDef` access now falls back to `jvm.classes[target.__class]` and exits safely with diagnostic if unresolved.
+   - Motivation:
+     - Targets recurring per-test failure signature:
+       - `Cannot read properties of null (reading '__classDef')`
+     - This is now the highest-priority blocker after `.get` bridge repair.
+
 Known Failing Symptoms (Latest CI Logs/Artifacts)
 -------------------------------------------------
 
 - Screenshot suite finishes but many tests fail during `runTest`.
+- Latest primary blocker progression:
+  - Earlier blocker in CI artifacts: `Missing JS member get for host receiver`.
+  - After bridge compatibility work in local replay: blocker shifts to `Cannot read properties of null (reading '__classDef')` in translated screenshot helper path.
 - Repeated deterministic blockers in browser log:
   - `TabsScreenshotTest`: `cn1_com_codename1_ui_Button_initLaf_com_codename1_ui_plaf_UIManager is not defined`
   - `OrientationLockScreenshotTest`: `document is not defined`
@@ -199,7 +255,7 @@ Priority Next Steps
 4. Validate `CN1SS` named test streams are emitted again (not only `default/bootstrap`).
 5. Validate `originalResolved=translated:...__impl` (or equivalent non-recursive path) in CI browser log after translated-method preservation patch.
 6. If white-frame reuse persists, capture and compare per-test `settleSig`/`canvasSig`/`canvasSource` to identify whether paint is not happening or capture target is still wrong.
-7. Fix per-test null receiver/init path (`__classDef` null) at first failing stack, not via broad fallbacks.
+7. Fix per-test null receiver/init path (`__classDef` null) at first failing stack in translated screenshot/helper execution (no new broad fallbacks).
 8. Fix missing `Button.initLaf(UIManager)` symbol resolution in worker runtime path.
 9. Fix worker-mode orientation lock path so DOM access is host-bridge mediated (no direct `document` access in worker).
 10. Confirm VM completeness stability in CI with parser/runtime patches (`expected 7` consistently).

Ports/JavaScriptPort/src/main/webapp/port.js

@@ -3181,6 +3181,10 @@ bindCiFallback("Cn1ssDeviceRunnerHelper.emitCurrentFormScreenshotDom", [
       } catch (originalErr) {
         emitDiagLine("PARPAR:DIAG:FALLBACK:cn1ssEmitCurrentFormScreenshotDom:originalInvokeErr="
           + String(originalErr && originalErr.message ? originalErr.message : originalErr));
+        if (originalErr && originalErr.stack) {
+          emitDiagLine("PARPAR:DIAG:FALLBACK:cn1ssEmitCurrentFormScreenshotDom:originalInvokeStack="
+            + String(originalErr.stack).split("\n").slice(0, 2).join(" | "));
+        }
         shouldUseDomFallback = true;
       } finally {
         cn1ssEmitCurrentFormScreenshotInvokeDepth = Math.max(0, cn1ssEmitCurrentFormScreenshotInvokeDepth - 1);
@@ -3328,7 +3332,11 @@ function installBaseTestOnShowLambdaShim() {
     if (!target || !target.__class) {
       return null;
     }
-    const classDef = target.__classDef;
+    const classDef = target.__classDef || (jvm.classes ? jvm.classes[target.__class] : null);
+    if (!classDef) {
+      emitDiagLine("PARPAR:DIAG:FALLBACK:baseTestOnShowLambda:noClassDef=1:class=" + String(target.__class || "null"));
+      return null;
+    }
     let method = (classDef && classDef.methods) ? classDef.methods[baseTestOnShowLambdaMethodId] : null;
     if (!method) {
       method = jvm.resolveVirtual(target.__class, baseTestOnShowLambdaMethodId);

vm/ByteCodeTranslator/src/javascript/browser_bridge.js

@@ -209,6 +209,19 @@
     if (value == null || typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean') {
       return value;
     }
+    // Avoid per-element host RPC on large typed-array reads (e.g. ImageData.data).
+    // Returning a clone transfers data once to the worker so get(index) executes locally.
+    if (typeof Uint8ClampedArray !== 'undefined' && value instanceof Uint8ClampedArray) {
+      return new Uint8Array(value);
+    }
+    if (typeof ArrayBuffer !== 'undefined') {
+      if (value instanceof ArrayBuffer) {
+        return value.slice(0);
+      }
+      if (typeof ArrayBuffer.isView === 'function' && ArrayBuffer.isView(value)) {
+        return value.slice ? value.slice(0) : value;
+      }
+    }
     return storeHostRef(value);
   }
 
@@ -330,12 +343,23 @@
       var fn = receiver[member];
       if (typeof fn === 'function') {
         value = fn.apply(receiver, args);
+      } else if (member === 'get' && args.length === 1 && receiver && typeof receiver.length === 'number') {
+        value = receiver[args[0] | 0];
+      } else if (member === 'set' && args.length === 2 && receiver && typeof receiver.length === 'number') {
+        receiver[args[0] | 0] = args[1];
+        value = null;
       } else if (!args.length && Object.prototype.hasOwnProperty.call(receiver, member)) {
         value = receiver[member];
       } else {
         throw new Error('Missing JS member ' + member + ' for host receiver');
       }
     }
+    if (kind === 'getter' && member === 'data' && value && typeof value.length === 'number') {
+      if (value.slice) {
+        return value.slice(0);
+      }
+      return Array.prototype.slice.call(value);
+    }
     noteDrawTarget(receiver, kind, member);
     if (isCanvasLike(receiver) && kind === 'method' && member === 'getContext') {
       global.__cn1LastDrawCanvas = receiver;

vm/ByteCodeTranslator/src/javascript/parparvm_runtime.js

@@ -740,6 +740,11 @@ const jvm = {
         const fn = receiver[bridge.member];
         if (typeof fn === "function") {
           result = fn.apply(receiver, nativeArgs);
+        } else if (bridge.member === "get" && nativeArgs.length === 1 && receiver && typeof receiver.length === "number") {
+          result = receiver[nativeArgs[0] | 0];
+        } else if (bridge.member === "set" && nativeArgs.length === 2 && receiver && typeof receiver.length === "number") {
+          receiver[nativeArgs[0] | 0] = nativeArgs[1];
+          result = null;
         } else if (!nativeArgs.length && Object.prototype.hasOwnProperty.call(receiver, bridge.member)) {
           result = receiver[bridge.member];
         } else {