diff --git a/AGENTS.md b/AGENTS.md
index 8b216e4..eaa5f3f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -8,6 +8,10 @@
 
 - GUI 与性能自动化先查 `scripts/README.md`、`scripts/emacs-gui-verifier.el`
   及既有 Makefile 入口；公共机制归 `scripts/`，具体业务场景归示例仓库。
+- 连续 resize 使用 `scripts/benchmark-ebox-resize.el` 的
+  `ebox-resize-benchmark-start`，适用于现有 ETAF 或独立 Ebox buffer。
+  按 README 选择范围、轮数和新证据文件；先验证前台与已加载版本，保留全部样本，
+  检查 `:valid` 与 `:within-limit`，同时比较内容规模，不能只比较 p95。
 - 遇到重复的渲染、交互、resize 或验证需求，优先扩展已登记入口。稳定的通用
   操作应主动固化为带参数、验证和说明的仓库工具，随后更新工具索引及本节路由。
 - `.omx/` 中的临时诊断是历史调查材料，不是日常运行入口。不要从中复制新的
diff --git a/Makefile b/Makefile
index 57bb559..7c75fbe 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 EMACS ?= emacs
 LOAD_PATH = -L . -L examples -L scripts -L ../ebox -L ../tp -L ../ecss
-SOURCES = etaf-view.el etaf-compiler.el etaf-component.el etaf-scheduler.el etaf-reactive.el etaf-observer.el etaf-context.el etaf-theme-tp.el etaf-resource.el etaf-data.el etaf-generation.el etaf-host.el etaf-retirement.el etaf-render-port.el etaf-renderer.el etaf-runtime.el etaf-behavior.el etaf-actions.el etaf-events.el etaf-performance.el etaf.el scripts/emacs-gui-verifier.el scripts/benchmark-scheduler-context.el
+SOURCES = etaf-view.el etaf-compiler.el etaf-component.el etaf-scheduler.el etaf-reactive.el etaf-observer.el etaf-context.el etaf-theme-tp.el etaf-resource.el etaf-data.el etaf-generation.el etaf-host.el etaf-retirement.el etaf-render-port.el etaf-renderer.el etaf-runtime.el etaf-behavior.el etaf-actions.el etaf-events.el etaf-performance.el etaf.el scripts/emacs-gui-verifier.el scripts/benchmark-scheduler-context.el scripts/benchmark-ebox-resize.el
 EXAMPLES = examples/etaf-counter-example.el examples/etaf-data-example.el examples/etaf-resource-example.el
-TESTS = tests/etaf-tests.el tests/etaf-compiler-tests.el tests/etaf-component-frontends-tests.el tests/etaf-render-view-tests.el tests/etaf-dynamic-components-tests.el tests/etaf-event-forwarding-tests.el tests/etaf-resource-tests.el tests/etaf-data-tests.el tests/etaf-theme-tp-tests.el tests/etaf-examples-tests.el tests/etaf-observer-tests.el tests/etaf-performance-tests.el tests/etaf-gui-verifier-tests.el tests/etaf-m0a-current-characterization-tests.el tests/etaf-interaction-contract-tests.el tests/etaf-m0b-component-manifest-tests.el tests/etaf-render-port-tests.el tests/etaf-generation-tests.el tests/etaf-host-tests.el tests/etaf-retirement-tests.el tests/etaf-scheduler-tests.el tests/etaf-g1-cross-layer-tests.el
+TESTS = tests/etaf-tests.el tests/etaf-compiler-tests.el tests/etaf-component-frontends-tests.el tests/etaf-render-view-tests.el tests/etaf-dynamic-components-tests.el tests/etaf-event-forwarding-tests.el tests/etaf-resource-tests.el tests/etaf-data-tests.el tests/etaf-theme-tp-tests.el tests/etaf-examples-tests.el tests/etaf-observer-tests.el tests/etaf-performance-tests.el tests/etaf-gui-verifier-tests.el tests/etaf-m0a-current-characterization-tests.el tests/etaf-interaction-contract-tests.el tests/etaf-m0b-component-manifest-tests.el tests/etaf-render-port-tests.el tests/etaf-generation-tests.el tests/etaf-host-tests.el tests/etaf-retirement-tests.el tests/etaf-scheduler-tests.el tests/etaf-g1-cross-layer-tests.el tests/etaf-resize-benchmark-tests.el
 
-.PHONY: test compile load checkdoc docs-check metadata-check scheduler-benchmark check clean
+.PHONY: test compile load checkdoc docs-check metadata-check scheduler-benchmark resize-benchmark-tests check clean
 
 test: compile
 	$(EMACS) -Q --batch $(LOAD_PATH) --eval "(setq load-prefer-newer t)" \
@@ -32,6 +32,10 @@ scheduler-benchmark:
 		-l scripts/benchmark-scheduler-context.el \
 		-f etaf-scheduler-benchmark-run
 
+resize-benchmark-tests:
+	$(EMACS) -Q --batch $(LOAD_PATH) --eval '(setq load-prefer-newer t)' \
+		-l tests/etaf-resize-benchmark-tests.el -f ert-run-tests-batch-and-exit
+
 checkdoc:
 	$(EMACS) -Q --batch --eval '(progn (require (quote checkdoc)) (dolist (directory (list "." "examples" "scripts")) (dolist (file (directory-files directory t)) (when (string-suffix-p ".el" file) (checkdoc-file file)))))'
 
diff --git a/scripts/README.md b/scripts/README.md
index b5856a4..19fa151 100644
--- a/scripts/README.md
+++ b/scripts/README.md
@@ -13,6 +13,9 @@ scenarios live in their respective example repositories:
 - `emacs-gui-verifier.el` defines `Scenario`, ordered `Action`, run-local
   `Context`, checkpoint sequencing, assertions, completion, and fail-closed
   evidence finalization.
+- `benchmark-ebox-resize.el` drives continuous pixel-width sweeps of any
+  existing mounted Ebox buffer, including ETAF apps, without taking over its
+  observer. See the existing-server entry below.
 - The legacy isolated runner `run-emacs-gui-verification.sh` owns one named daemon, explicit load paths,
   external application activation, recorder lifecycle, driver loading, report
   generation, and exact cleanup.
@@ -48,3 +51,70 @@ Only `VERDICT=PASS` completes that runner's evidence bundle. An existing-server
 run reports its actual interaction assertions and inspected screenshots
 separately. A failed recorder is never evidence of continuous capture, and
 neither screenshots nor recording establish an operation latency bound.
+
+## Continuous resize on the existing server
+
+Use this entry for resize performance investigations instead of copying the
+historical `.omx/component-api-implementation/*continuous-resize*.el` probes.
+First show the intended buffer in the user's existing foreground GUI frame.
+Preserve its font and chrome. Compile changed product modules before loading
+them; `make compile` in this repository also compiles the benchmark tool.
+
+```sh
+emacsclient --eval '(progn
+  (load "/path/to/etaf/scripts/benchmark-ebox-resize.elc" nil t t)
+  (ebox-resize-benchmark-start "*Your app*" 480 1400
+    :step 32 :rounds 3 :output "/tmp/resize-run-1.eldata"))'
+```
+
+The bounds are outer-frame pixels. Every round goes from narrow to wide and
+back, including both endpoints even when the step does not divide the range.
+The last measured request returns to the initial width. Consecutive equal
+widths are omitted because they request no resize; no warmup or slow sample is
+dropped. The function returns immediately. Poll or cancel this owned run with:
+
+```elisp
+(ebox-resize-benchmark-status)
+(ebox-resize-benchmark-cancel)
+```
+
+`:delay` (default 0.01 seconds) runs between completed publications;
+`:timeout` (default 5 seconds) bounds startup, publication and final settling.
+The tool waits for a preceding render's GC lease to end before recording the
+baseline, and for its own run's lease to end before accepting the final result.
+Unsupported sizes,
+changed targets/focus/font/height, publication failures and cancellation produce
+invalid/incomplete evidence. Advice and timers are removed on success, error,
+quit and timeout. Failure leaves the last applied width; it does not fight a
+user's subsequent window changes. No server, frame, application buffer, observer, profiler
+or GC policy is created/replaced to make the benchmark pass.
+
+Use a **new output path** each time. UTF-8 `.eldata` reports retain all requests,
+all completed samples, actual published dimensions, node/text counts, GC,
+per-operation CPU time, code origins and hashes. Optional `:phases '(FUNCTIONS…)`
+records inclusive phase durations for loaded `ebox-`, `tp-` and `etaf-` provider
+functions. The driver and outer publication boundary cannot be selected as
+phases; nested durations must not be summed.
+Publication timing ends when the real public Ebox viewport call returns.
+Request→publication also includes event-loop delivery. Neither metric proves
+compositor presentation, absence of flicker, or every interaction's correctness;
+use the existing visual scenario/capture tools for those claims.
+
+`:valid t` requires complete correctly attributed publication coverage.
+`:within-limit t` additionally requires **every** request→publication sample to
+meet `:limit-ms` (default 50). Inspect p95 **and** max, including GC samples.
+Compare payload counts at matching widths before making speedup claims. A
+different page size/content or loaded version is a different baseline.
+
+Code origins and disk hashes alone cannot establish when a running function was
+loaded. After recompilation, `:reload-files '("/checkout/ebox/ebox-viewport.elc" …)`
+explicitly loads the chosen fresh bytecode before instrumentation. `:code`
+contains every explicitly loaded file's canonical path, source/bytecode hashes
+and load result, plus observed core function and benchmark driver origins;
+matching origins are marked `:reloaded t`. Choose the affected modules; do not reload
+application component declarations blindly. Without this option, report code
+origin observations separately from independent evidence of a fresh GUI load.
+
+Run the tool's regression checks with `make resize-benchmark-tests`; they also
+run in the full `make check` gate. Application-specific data setup and interaction
+assertions remain in the example repositories, not this resize driver.
diff --git a/scripts/benchmark-ebox-resize.el b/scripts/benchmark-ebox-resize.el
new file mode 100644
index 0000000..392cf71
--- /dev/null
+++ b/scripts/benchmark-ebox-resize.el
@@ -0,0 +1,497 @@
+;;; benchmark-ebox-resize.el --- Existing-frame resize benchmark -*- lexical-binding: t; -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+
+;; Drive any mounted Ebox buffer through a pixel-width sweep in its existing
+;; GUI frame.  This includes ETAF apps without depending on ETAF Runtime.
+;; Publication completion, rather than a fixed sleep, advances each request.
+;; The visual scenario engine remains responsible for screenshots/interaction
+;; assertions; this tool measures request and publication boundaries only.
+;; Internal Ebox state is read for bounded diagnostics, never mutated.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'ebox)
+(require 'ebox-viewport)
+
+(declare-function profiler-running-p "profiler" ())
+(declare-function ebox-native-reflow-runtime-report "ebox-native-reflow" ())
+
+(defvar ebox-resize-benchmark--run nil
+  "The sole active run, including its owned timers and instrumentation.")
+(defvar ebox-resize-benchmark--last-result nil
+  "Scalar report for the most recently finished run.")
+(defvar ebox-resize-benchmark--phases nil
+  "Dynamically bound phase counters for the current measured publication.")
+(defvar ebox-resize-benchmark--inside nil
+  "Non-nil inside the outer measured public viewport operation.")
+
+(defun ebox-resize-benchmark--widths (minimum maximum step rounds initial)
+  "Build MINIMUM–MAXIMUM sweeps using STEP and ROUNDS, returning to INITIAL.
+Consecutive duplicate widths, which request no change, are omitted."
+  (unless (and (integerp minimum) (> minimum 0)
+               (integerp maximum) (> maximum minimum)
+               (integerp step) (> step 0)
+               (integerp rounds) (> rounds 0))
+    (error "Resize requires positive integer bounds, step and rounds; min < max"))
+  (let* ((ascending (number-sequence minimum maximum step))
+         (up (if (= (car (last ascending)) maximum) ascending
+               (append ascending (list maximum))))
+         (cycle (append up (cdr (reverse up))))
+         (previous initial) widths)
+    (dolist (width (append (apply #'append (make-list rounds cycle))
+                          (list initial)))
+      (unless (= width previous) (push width widths))
+      (setq previous width))
+    (nreverse widths)))
+
+(defun ebox-resize-benchmark--summary (values)
+  "Return count, p50, p95 and max for all numeric VALUES."
+  (when values
+    (let ((sorted (sort (copy-sequence values) #'<)))
+      (list :count (length values)
+            :p50-ms (nth (1- (ceiling (* .5 (length values)))) sorted)
+            :p95-ms (nth (1- (ceiling (* .95 (length values)))) sorted)
+            :max-ms (car (last sorted))))))
+
+(defun ebox-resize-benchmark--condition (condition)
+  "Summarize CONDITION without printing arbitrary condition data."
+  (list :symbol (car condition)
+        :message (if (stringp (cadr condition))
+                     (truncate-string-to-width (cadr condition) 512 nil nil t)
+                   "Non-text condition data omitted")))
+
+(defun ebox-resize-benchmark--hash-file (file)
+  "Return FILE's literal SHA-256."
+  (with-temp-buffer
+    (insert-file-contents-literally file)
+    (secure-hash 'sha256 (current-buffer))))
+
+(defun ebox-resize-benchmark--file-evidence (file)
+  "Return canonical FILE and source paths with their literal hashes."
+  (let* ((path (file-truename file))
+         (source (if (string-suffix-p ".elc" path) (substring path 0 -1) path)))
+    (list :file path :sha256 (ebox-resize-benchmark--hash-file path)
+          :source (and (file-readable-p source) (file-truename source))
+          :source-sha256 (and (file-readable-p source)
+                              (ebox-resize-benchmark--hash-file source)))))
+
+(defun ebox-resize-benchmark--code (files)
+  "Reload explicitly supplied compiled FILES and report relevant code origins.
+Never reload application declarations implicitly.  Without FILES, origin and
+disk hashes are observations, not proof that memory matches current bytecode."
+  (dolist (file files)
+    (unless (and (stringp file) (string-suffix-p ".elc" file)
+                 (file-readable-p file)
+                 (not (file-newer-than-file-p (substring file 0 -1) file)))
+      (error "Missing or stale compiled reload file: %s" file)))
+  (let ((reloads
+         (mapcar (lambda (file)
+                   (let* ((evidence (ebox-resize-benchmark--file-evidence file))
+                          (loaded (load (plist-get evidence :file) nil t t)))
+                     (unless (equal evidence (ebox-resize-benchmark--file-evidence file))
+                       (error "Reload file changed while loading: %s" file))
+                     (append evidence (list :loaded (and loaded t))))) files)))
+    (list :reload-files reloads :functions
+     (mapcar
+   (lambda (symbol)
+     (let* ((origin (symbol-file symbol 'defun))
+            (source (and origin
+                         (if (string-suffix-p ".elc" origin)
+                             (substring origin 0 -1) origin))))
+       (unless (and origin (file-readable-p origin))
+         (error "No readable origin for resize function: %s" symbol))
+       (when (and (string-suffix-p ".elc" origin)
+                  (file-newer-than-file-p source origin))
+         (error "Recompile stale resize bytecode: %s" origin))
+       (list :function symbol :origin origin
+             :origin-sha256 (ebox-resize-benchmark--hash-file origin)
+             :source-sha256 (and (file-readable-p source)
+                                 (ebox-resize-benchmark--hash-file source))
+             :reloaded (and (member (file-truename origin)
+                                   (mapcar #'file-truename files)) t))))
+   '(ebox-rerender-buffer-with-context ebox--window-size-change
+     ebox-surface-update-buffer-viewport
+     ebox-incremental-prepare-viewport-commit ebox-resize-benchmark-start)))))
+
+(defun ebox-resize-benchmark--payload (buffer)
+  "Read bounded workload facts from BUFFER, without copying runtime graphs."
+  (let* ((state (and (buffer-live-p buffer) (ebox--buffer-render-state buffer)))
+         (nodes (plist-get state :node-table)))
+    (list :nodes (and (hash-table-p nodes) (hash-table-count nodes))
+          :characters (and (buffer-live-p buffer)
+                           (with-current-buffer buffer (buffer-size)))
+          :viewport (list (plist-get state :viewport-width)
+                          (plist-get state :viewport-height)))))
+
+(defun ebox-resize-benchmark--guard ()
+  "Require the captured foreground buffer, frame, font and height."
+  (let* ((run ebox-resize-benchmark--run)
+         (frame (plist-get run :frame))
+         (window (plist-get run :window))
+         (buffer (plist-get run :buffer)))
+    (unless (and (frame-live-p frame) (display-graphic-p frame)
+                 (eq frame (selected-frame)) (eq t (frame-visible-p frame))
+                 (eq t (frame-focus-state frame)) (window-live-p window)
+                 (eq window (selected-window))
+                 (eq buffer (window-buffer window))
+                 (ebox-surface-buffer-mounted-p buffer)
+                 (equal (frame-parameter frame 'font) (plist-get run :font))
+                 (= (frame-pixel-height frame) (plist-get run :height))
+                 (not (active-minibuffer-window)))
+      (error "Resize target, focus, font, height or mount changed"))))
+
+(defun ebox-resize-benchmark--phase (name original &rest arguments)
+  "Record inclusive NAME timing around ORIGINAL called with ARGUMENTS."
+  (if (not ebox-resize-benchmark--phases)
+      (apply original arguments)
+    (let ((started (float-time)) (gc-start gc-elapsed))
+      (unwind-protect (apply original arguments)
+        (let ((row (or (gethash name ebox-resize-benchmark--phases)
+                       (puthash name (vector 0 0.0 0.0)
+                                ebox-resize-benchmark--phases))))
+          (cl-incf (aref row 0))
+          (cl-incf (aref row 1) (* 1000 (- (float-time) started)))
+          (cl-incf (aref row 2) (* 1000 (- gc-elapsed gc-start))))))))
+
+(defun ebox-resize-benchmark--write (file report)
+  "Write REPORT as UTF-8 data to a new FILE, without overwriting evidence."
+  (let ((coding-system-for-write 'utf-8-unix))
+    (with-temp-buffer
+      (prin1 report (current-buffer))
+      (insert "\n")
+      (write-region (point-min) (point-max) file nil 'silent nil 'excl))))
+
+(defun ebox-resize-benchmark--finish (status &optional condition)
+  "Release owned resources and record STATUS and optional CONDITION."
+  (let ((run ebox-resize-benchmark--run))
+    (when run
+      ;; Cleanup precedes report construction: even a dead buffer or write
+      ;; failure cannot leave a timed benchmark attached to the application.
+      (setq ebox-resize-benchmark--run nil)
+      (dolist (key '(:timer :watchdog))
+        (when (timerp (plist-get run key)) (cancel-timer (plist-get run key))))
+      (advice-remove 'ebox-rerender-buffer-with-context
+                     #'ebox-resize-benchmark--publication)
+      (dolist (binding (plist-get run :bindings))
+        (advice-remove (car binding) (cdr binding)))
+      (let* ((samples (nreverse (plist-get run :samples)))
+             (valid (and (eq status 'complete)
+                         (= (length samples) (plist-get run :planned-count))
+                         (cl-every (lambda (sample) (plist-get sample :published)) samples)))
+             (publication (ebox-resize-benchmark--summary
+                           (delq nil (mapcar (lambda (s) (plist-get s :publication-ms)) samples))))
+             (latency (ebox-resize-benchmark--summary
+                       (delq nil (mapcar (lambda (s) (plist-get s :request-to-published-ms)) samples))))
+             (report
+              (list :format-version 1 :status status :valid valid
+                    :failure (and condition (ebox-resize-benchmark--condition condition))
+                    :pid (emacs-pid) :emacs-version emacs-version
+                    :system-type system-type :buffer (plist-get run :buffer-name)
+                    :font (plist-get run :font) :height (plist-get run :height)
+                    :range (plist-get run :range) :rounds (plist-get run :rounds)
+                    :step (plist-get run :step) :delay (plist-get run :delay)
+                    :requested-widths (plist-get run :widths)
+                    :start-width (plist-get run :start-width)
+                    :gc-before (plist-get run :gc-policy)
+                    :gc-after (list gc-cons-threshold gc-cons-percentage)
+                    :whole-run-gcs (- gcs-done (plist-get run :gcs))
+                    :whole-run-gc-ms (* 1000 (- gc-elapsed (plist-get run :gc)))
+                    :code (plist-get run :code) :native (plist-get run :native)
+                    :payload-before (plist-get run :payload)
+                    :payload-after (ebox-resize-benchmark--payload (plist-get run :buffer))
+                    :planned-count (plist-get run :planned-count)
+                    :requested-count (length samples)
+                    :completed-count (cl-count-if (lambda (s) (plist-get s :published)) samples)
+                    :publication publication :request-to-published latency
+                    :limit-ms (plist-get run :limit)
+                    :within-limit (and valid latency
+                                       (<= (plist-get latency :max-ms) (plist-get run :limit)))
+                    :phase-columns '(calls inclusive-ms gc-ms)
+                    :samples samples)))
+        (setq ebox-resize-benchmark--last-result report)
+        (condition-case write-error
+            (ebox-resize-benchmark--write (plist-get run :output) report)
+          ((error quit)
+           (setq ebox-resize-benchmark--last-result
+                 (plist-put report :evidence-write-error
+                            (ebox-resize-benchmark--condition write-error)))
+           (setf (plist-get ebox-resize-benchmark--last-result :status) 'failed
+                 (plist-get ebox-resize-benchmark--last-result :valid) nil
+                 (plist-get ebox-resize-benchmark--last-result :within-limit) nil)
+           (message "Resize evidence could not be written: %s"
+                    (plist-get (ebox-resize-benchmark--condition write-error) :message))
+           (unless condition (signal (car write-error) (cdr write-error)))))))))
+
+(defun ebox-resize-benchmark--abort (condition)
+  "Record failure and clean up before re-signaling original CONDITION."
+  (condition-case report-error
+      (ebox-resize-benchmark--finish 'failed condition)
+    ((error quit)
+     (message "Resize failure report unavailable: %s"
+              (plist-get (ebox-resize-benchmark--condition report-error) :message))))
+  (signal (car condition) (cdr condition)))
+
+(defun ebox-resize-benchmark--schedule ()
+  "Schedule the next request after the configured event-loop delay."
+  (setf (plist-get ebox-resize-benchmark--run :timer)
+        (run-at-time (plist-get ebox-resize-benchmark--run :delay)
+                     nil #'ebox-resize-benchmark--next)))
+
+(defun ebox-resize-benchmark--timeout ()
+  "Fail a request that did not publish within its configured deadline."
+  (when ebox-resize-benchmark--run
+    (ebox-resize-benchmark--finish 'failed '(error "Resize publication timed out"))))
+
+(defun ebox-resize-benchmark--settled ()
+  "Wait for the product's own GC lease to restore, without changing policy."
+  (when ebox-resize-benchmark--run
+    (condition-case condition
+        (progn
+          (ebox-resize-benchmark--guard)
+          (cond
+           ((and (not ebox--deferred-render-gc-state)
+                 (equal (list gc-cons-threshold gc-cons-percentage)
+                        (plist-get ebox-resize-benchmark--run :gc-policy)))
+            (ebox-resize-benchmark--finish 'complete))
+           ((>= (float-time) (plist-get ebox-resize-benchmark--run :settle-deadline))
+            (error "GC policy did not restore before the settle deadline"))
+           (t
+            (setf (plist-get ebox-resize-benchmark--run :timer)
+                  (run-at-time .05 nil #'ebox-resize-benchmark--settled)))))
+      ((error quit) (ebox-resize-benchmark--abort condition)))))
+
+(defun ebox-resize-benchmark--publication (original buffer width &optional height)
+  "Measure ORIGINAL publishing BUFFER for WIDTH and HEIGHT."
+  (if (or ebox-resize-benchmark--inside (not ebox-resize-benchmark--run)
+          (not (plist-get ebox-resize-benchmark--run :armed))
+          (not (eq (get-buffer buffer) (plist-get ebox-resize-benchmark--run :buffer))))
+      (funcall original buffer width height)
+    (let* ((ebox-resize-benchmark--inside t)
+           (run ebox-resize-benchmark--run)
+           (sample (plist-get run :current))
+           (expected (and sample (not (plist-get sample :published))))
+           (phase-data (make-hash-table :test #'eq))
+           before-failure failure result completed)
+      (unwind-protect
+          (progn
+            (condition-case condition (ebox-resize-benchmark--guard)
+              (error (setq before-failure condition)))
+            (let ((started (float-time)) (cpu (current-cpu-time))
+                  (gc gc-elapsed) (gcs gcs-done)
+                  (policy (list gc-cons-threshold gc-cons-percentage)))
+              ;; Attribution errors belong to this diagnostic, not the app.
+              ;; Always execute the real call once and preserve its outcome.
+              (condition-case condition
+                  (let ((ebox-resize-benchmark--phases phase-data))
+                    (setq result (funcall original buffer width height)))
+                ((error quit) (setq failure condition)))
+              (let ((finished (float-time)) (cpu-end (current-cpu-time))
+                    (gc-end gc-elapsed) (gcs-end gcs-done))
+                ;; An observer may cancel this run or start a replacement.
+                ;; Never mutate a retired sample or schedule through a new run.
+                (when (eq run ebox-resize-benchmark--run)
+                  (condition-case condition
+                      (progn
+                        (unless (and expected (eq sample (plist-get run :current)))
+                          (error "Unattributed or duplicate publication during resize"))
+                        (let ((payload (ebox-resize-benchmark--payload (get-buffer buffer)))
+                              (window (plist-get run :window)) phases)
+                          (maphash (lambda (name values) (push (cons name values) phases))
+                                   phase-data)
+                          (setf (plist-get sample :publication-ms) (* 1000 (- finished started))
+                                (plist-get sample :request-to-published-ms)
+                                (* 1000 (- finished (plist-get sample :requested-at)))
+                                (plist-get sample :cpu-ms)
+                                (* 1000.0 (/ (- (car cpu-end) (car cpu)) (float (cdr cpu))))
+                                (plist-get sample :gc-ms) (* 1000 (- gc-end gc))
+                                (plist-get sample :gcs) (- gcs-end gcs)
+                                (plist-get sample :gc-policy) policy
+                                (plist-get sample :payload) payload
+                                (plist-get sample :phases) phases
+                                (plist-get sample :foreground-before) (not before-failure))
+                          (when failure (signal (car failure) (cdr failure)))
+                          (when before-failure (signal (car before-failure) (cdr before-failure)))
+                          (ebox-resize-benchmark--guard)
+                          (setf (plist-get sample :foreground-after) t)
+                          (unless (and (= (frame-pixel-width (plist-get run :frame))
+                                          (plist-get sample :width))
+                                       (equal (list width height)
+                                              (list (ebox-viewport-window-width window)
+                                                    (window-body-height window)))
+                                       (equal (list width height) (plist-get payload :viewport)))
+                            (error "Requested, actual and published viewport dimensions disagree"))
+                          (when (> finished (+ (plist-get sample :requested-at)
+                                               (plist-get run :timeout)))
+                            (error "Resize publication exceeded its deadline"))
+                          (setf (plist-get sample :published) t)
+                          (cancel-timer (plist-get run :watchdog))
+                          (setf (plist-get run :watchdog) nil)
+                          (ebox-resize-benchmark--schedule)))
+                    ((error quit) (ebox-resize-benchmark--observation-failed run condition))))))
+            (setq completed t)
+            (if failure (signal (car failure) (cdr failure)) result))
+        (unless completed
+          (ebox-resize-benchmark--observation-failed
+           run '(error "Publication exited before observation completed")))))))
+
+(defun ebox-resize-benchmark--observation-failed (run condition)
+  "Retire captured RUN with CONDITION without changing a product return value."
+  (when (eq run ebox-resize-benchmark--run)
+    (condition-case report-error
+        (ebox-resize-benchmark--finish 'failed condition)
+      ((error quit)
+       (message "Resize failure report unavailable: %s"
+                (plist-get (ebox-resize-benchmark--condition report-error) :message))))))
+
+(defun ebox-resize-benchmark--ready-p (run)
+  "Arm RUN after preceding rendering has released its GC lease."
+  (or (plist-get run :armed)
+      (cond
+       ((>= (float-time) (plist-get run :ready-deadline))
+        (error "Preceding render did not settle before the startup deadline"))
+       (ebox--deferred-render-gc-state
+        (ebox-resize-benchmark--schedule)
+        nil)
+       (t
+        (setf (plist-get run :gc-policy) (list gc-cons-threshold gc-cons-percentage)
+              (plist-get run :gcs) gcs-done
+              (plist-get run :gc) gc-elapsed
+              (plist-get run :payload)
+              (ebox-resize-benchmark--payload (plist-get run :buffer))
+              (plist-get run :armed) t)))))
+
+(defun ebox-resize-benchmark--next ()
+  "Issue one resize, then return to Emacs until its publication completes."
+  (when ebox-resize-benchmark--run
+    (condition-case condition
+        (let ((inhibit-quit nil))
+          (ebox-resize-benchmark--guard)
+          (let* ((run ebox-resize-benchmark--run)
+                 (frame (plist-get run :frame))
+                 (width (car (plist-get run :remaining))))
+            (setf (plist-get run :timer) nil)
+            (when (ebox-resize-benchmark--ready-p run)
+            (if (not width)
+                (progn
+                  (setf (plist-get run :settle-deadline)
+                        (+ (float-time) (plist-get run :timeout)))
+                  (ebox-resize-benchmark--settled))
+              ;; Allocate every mutable slot before sharing this record with
+              ;; the publication callback: plist setters may replace a head
+              ;; when adding a previously absent key.
+              (let ((sample (list :index (1+ (length (plist-get run :samples)))
+                                  :width width :requested-at (float-time)
+                                  :publication-ms nil :request-to-published-ms nil
+                                  :cpu-ms nil :gc-ms nil :gcs nil :gc-policy nil
+                                  :payload nil :phases nil :published nil
+                                  :foreground-before nil :foreground-after nil))
+                    (frame-resize-pixelwise t))
+                (setf (plist-get run :remaining) (cdr (plist-get run :remaining))
+                      (plist-get run :current) sample
+                      (plist-get run :samples) (cons sample (plist-get run :samples))
+                      (plist-get run :watchdog)
+                      (run-at-time (plist-get run :timeout) nil
+                                   #'ebox-resize-benchmark--timeout))
+                (set-frame-size frame
+                                (- width (- (frame-pixel-width frame)
+                                            (frame-text-width frame)))
+                                (frame-text-height frame) t)
+                (redisplay t))))))
+      ((error quit) (ebox-resize-benchmark--abort condition)))))
+
+;;;###autoload
+(cl-defun ebox-resize-benchmark-start
+    (buffer minimum maximum &key (step 32) (rounds 3) (delay .01)
+            (timeout 5.0) (limit-ms 50.0) output reload-files phases)
+  "Resize existing BUFFER from MINIMUM to MAXIMUM outer-frame pixels.
+STEP and ROUNDS control repeated narrow→wide→narrow sweeps.  The final measured
+request restores the starting width.  OUTPUT must name a new evidence file.
+DELAY spaces completed publications; TIMEOUT bounds startup and publication.
+LIMIT-MS applies to all request→publication samples, including GC and first use.
+RELOAD-FILES explicitly reloads fresh compiled modules before measurement.
+PHASES names loaded ebox-/tp-/etaf- functions for inclusive diagnostics.
+Use `ebox-resize-benchmark-status' to poll and `ebox-resize-benchmark-cancel'
+to stop.  Failure stops at the current width.  No frame or server is created,
+no application observer is replaced, and no GC/font policy is changed."
+  (when ebox-resize-benchmark--run (error "A resize benchmark is already active"))
+  (unless (and (stringp output) (not (file-exists-p output))
+               (file-directory-p (file-name-directory (expand-file-name output)))
+               (numberp delay) (> delay 0) (numberp timeout) (> timeout delay)
+               (numberp limit-ms) (> limit-ms 0))
+    (error "Resize requires a new output path and positive delay/timeout/limit"))
+  (when (and (fboundp 'profiler-running-p) (profiler-running-p))
+    (error "Stop profiling before collecting resize latency"))
+  (dolist (name phases)
+    (unless (and (symbolp name) (fboundp name)
+                 (string-match-p "\\`\\(?:ebox\\|tp\\|etaf\\)-" (symbol-name name))
+                 (not (string-prefix-p "ebox-resize-benchmark-" (symbol-name name)))
+                 (not (eq name 'ebox-rerender-buffer-with-context)))
+      (error "Invalid or duplicate outer measurement phase: %s" name)))
+  (let* ((target (get-buffer buffer))
+         (frame (selected-frame))
+         (initial (frame-pixel-width frame))
+         (widths (ebox-resize-benchmark--widths minimum maximum step rounds initial)))
+    (setq ebox-resize-benchmark--last-result nil
+          ebox-resize-benchmark--run
+          (list :buffer target :buffer-name (and target (buffer-name target))
+                :frame frame :window (selected-window)
+                :font (frame-parameter frame 'font) :height (frame-pixel-height frame)
+                :gc-policy (list gc-cons-threshold gc-cons-percentage)
+                :gcs gcs-done :gc gc-elapsed :code nil :native nil :payload nil
+                :start-width initial :widths widths :remaining widths
+                :planned-count (length widths) :range (list minimum maximum)
+                :rounds rounds :step step :delay delay :timeout timeout
+                :limit limit-ms :output (expand-file-name output)
+                :timer nil :watchdog nil :current nil :samples nil
+                :bindings nil :settle-deadline nil :armed nil :ready-deadline nil))
+    (condition-case condition
+        (progn
+          (ebox-resize-benchmark--guard)
+          (setf (plist-get ebox-resize-benchmark--run :code)
+                (ebox-resize-benchmark--code reload-files)
+                (plist-get ebox-resize-benchmark--run :native)
+                (and (fboundp 'ebox-native-reflow-runtime-report)
+                     (ebox-native-reflow-runtime-report))
+                (plist-get ebox-resize-benchmark--run :payload)
+                (ebox-resize-benchmark--payload target)
+                (plist-get ebox-resize-benchmark--run :gcs) gcs-done
+                (plist-get ebox-resize-benchmark--run :gc) gc-elapsed)
+          (ebox-resize-benchmark--guard)
+          (setf (plist-get ebox-resize-benchmark--run :ready-deadline)
+                (+ (float-time) timeout))
+          (dolist (name (delete-dups (copy-sequence phases)))
+            (let ((wrapper (apply-partially #'ebox-resize-benchmark--phase name)))
+              (push (cons name wrapper) (plist-get ebox-resize-benchmark--run :bindings))
+              (advice-add name :around wrapper)))
+          (advice-add 'ebox-rerender-buffer-with-context :around
+                      #'ebox-resize-benchmark--publication)
+          (ebox-resize-benchmark--schedule)
+          (ebox-resize-benchmark-status))
+      ((error quit) (ebox-resize-benchmark--abort condition)))))
+
+;;;###autoload
+(defun ebox-resize-benchmark-status ()
+  "Return bounded progress or the last run's completion/latency summary."
+  (if ebox-resize-benchmark--run
+      (list :status 'running
+            :requested (length (plist-get ebox-resize-benchmark--run :samples))
+            :planned (plist-get ebox-resize-benchmark--run :planned-count)
+            :output (plist-get ebox-resize-benchmark--run :output))
+    (cl-loop for key in '(:status :valid :failure :completed-count :planned-count
+                         :publication :request-to-published :within-limit
+                         :evidence-write-error)
+             append (list key (plist-get ebox-resize-benchmark--last-result key)))))
+
+;;;###autoload
+(defun ebox-resize-benchmark-cancel ()
+  "Stop this benchmark and release its timers and advice."
+  (interactive)
+  (ebox-resize-benchmark--finish 'cancelled '(quit "Resize cancelled"))
+  (ebox-resize-benchmark-status))
+
+(provide 'benchmark-ebox-resize)
+;;; benchmark-ebox-resize.el ends here
diff --git a/tests/etaf-resize-benchmark-tests.el b/tests/etaf-resize-benchmark-tests.el
new file mode 100644
index 0000000..f2a3b93
--- /dev/null
+++ b/tests/etaf-resize-benchmark-tests.el
@@ -0,0 +1,337 @@
+;;; etaf-resize-benchmark-tests.el --- Resize driver contracts -*- lexical-binding: t; -*-
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'benchmark-ebox-resize)
+
+(defmacro etaf-resize-test--with-run (&rest body)
+  "Evaluate BODY with isolated evidence and deterministic frame/publication IO."
+  (declare (indent 0) (debug t))
+  `(let* ((directory (make-temp-file "etaf-resize-test-" t))
+          (output (expand-file-name "result.eldata" directory))
+          (buffer (generate-new-buffer " *resize-test*"))
+          (ebox-resize-benchmark--run nil)
+          (ebox-resize-benchmark--last-result nil)
+          (ebox--deferred-render-gc-state nil)
+          (width 600))
+     (unwind-protect
+         (cl-letf (((symbol-function 'ebox-resize-benchmark--guard) #'ignore)
+                   ((symbol-function 'ebox-resize-benchmark--code) (lambda (_) nil))
+                   ((symbol-function 'ebox-native-reflow-runtime-report) #'ignore)
+                   ((symbol-function 'ebox-resize-benchmark--payload)
+                    (lambda (_buffer) (list :nodes 3 :characters 4 :viewport (list width 24))))
+                   ((symbol-function 'frame-pixel-width) (lambda (&optional _) width))
+                   ((symbol-function 'frame-text-width) (lambda (&optional _) width))
+                   ((symbol-function 'frame-text-height) (lambda (&optional _) 400))
+                   ((symbol-function 'ebox-viewport-window-width) (lambda (_) width))
+                   ((symbol-function 'window-body-height) (lambda (&rest _) 24))
+                   ((symbol-function 'redisplay) #'ignore)
+                   ((symbol-function 'set-frame-size)
+                    (lambda (_frame new-width _height &optional _) (setq width new-width))))
+           ,@body)
+       (when ebox-resize-benchmark--run
+         (ebox-resize-benchmark-cancel))
+       (when (buffer-live-p buffer) (kill-buffer buffer))
+       (delete-directory directory t))))
+
+(defun etaf-resize-test--tick ()
+  "Consume the owned driver timer and execute one request synchronously."
+  (cancel-timer (plist-get ebox-resize-benchmark--run :timer))
+  (ebox-resize-benchmark--next))
+
+(ert-deftest etaf-resize-widths-cover-both-endpoints-and-return ()
+  "Non-divisible ranges retain their widest point on every sweep."
+  (should (equal (ebox-resize-benchmark--widths 400 505 40 2 600)
+                 '(400 440 480 505 480 440 400 440 480 505 480 440 400 600)))
+  (should (equal (ebox-resize-benchmark--widths 400 500 100 1 400)
+                 '(500 400)))
+  (dolist (args '((0 500 1 1 400) (500 400 1 1 400)
+                  (400 500 0 1 400) (400 500 1 0 400)))
+    (should-error (apply #'ebox-resize-benchmark--widths args))))
+
+(ert-deftest etaf-resize-completion-keeps-every-publication-and-restores-width ()
+  "Only successful publication advances the driver; all samples are retained."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :step 200 :rounds 1 :delay 10 :timeout 20 :output output)
+    (let ((planned (plist-get ebox-resize-benchmark--run :planned-count)))
+      (dotimes (_ planned)
+        (etaf-resize-test--tick)
+        (should-not (plist-get ebox-resize-benchmark--run :timer))
+        (should (timerp (plist-get ebox-resize-benchmark--run :watchdog)))
+        (should (eq :published
+                    (ebox-resize-benchmark--publication (lambda (&rest _) :published)
+                                                        buffer width 24)))
+        (should (timerp (plist-get ebox-resize-benchmark--run :timer)))
+        (should-not (plist-get ebox-resize-benchmark--run :watchdog)))
+      (etaf-resize-test--tick)
+      (should-not ebox-resize-benchmark--run)
+      (should (= width 600))
+      (should (plist-get ebox-resize-benchmark--last-result :valid))
+      (should (= planned (plist-get ebox-resize-benchmark--last-result :completed-count)))
+      (should (file-exists-p output))
+      (should-not (advice-member-p #'ebox-resize-benchmark--publication
+                                  'ebox-rerender-buffer-with-context)))))
+
+(ert-deftest etaf-resize-publication-error-and-quit-preserve-cause-and-cleanup ()
+  "Original errors and C-g cannot leave advice or timers attached."
+  (dolist (failure '((error "original publication failure") (quit "publication interrupted")))
+    (etaf-resize-test--with-run
+      (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+      (etaf-resize-test--tick)
+      (let ((watchdog (plist-get ebox-resize-benchmark--run :watchdog)) caught)
+        (condition-case condition
+            (ebox-resize-benchmark--publication
+             (lambda (&rest _) (signal (car failure) (cdr failure))) buffer width 24)
+          ((error quit) (setq caught condition)))
+        (should (equal caught failure))
+        (should-not ebox-resize-benchmark--run)
+        (should-not (memq watchdog timer-list))
+        (should-not (advice-member-p #'ebox-resize-benchmark--publication
+                                    'ebox-rerender-buffer-with-context))
+        (should (= 0 (plist-get ebox-resize-benchmark--last-result :completed-count)))
+        (should-not (plist-get ebox-resize-benchmark--last-result :valid))))))
+
+(ert-deftest etaf-resize-timeout-is-incomplete-and-releases-owned-resources ()
+  "No publication must produce failed evidence, never a successful sample."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (let ((watchdog (plist-get ebox-resize-benchmark--run :watchdog)))
+      (ebox-resize-benchmark--timeout)
+      (should-not ebox-resize-benchmark--run)
+      (should-not (memq watchdog timer-list))
+      (should (eq 'failed (plist-get ebox-resize-benchmark--last-result :status)))
+      (should (= 1 (plist-get ebox-resize-benchmark--last-result :requested-count)))
+      (should (= 0 (plist-get ebox-resize-benchmark--last-result :completed-count))))))
+
+(ert-deftest etaf-resize-report-failure-preserves-publication-failure ()
+  "A secondary write failure is visible while the original error survives."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (let (warning)
+      (cl-letf (((symbol-function 'ebox-resize-benchmark--write)
+                 (lambda (&rest _) (error "disk failure")))
+                ((symbol-function 'message)
+                 (lambda (format-string &rest args)
+                   (setq warning (apply #'format format-string args)))))
+        (should (equal '(error "original")
+                       (should-error (ebox-resize-benchmark--abort '(error "original"))))))
+      (should (string-match-p "disk failure" warning))
+      (should (plist-get ebox-resize-benchmark--last-result :evidence-write-error))
+      (should-not ebox-resize-benchmark--run))))
+
+(ert-deftest etaf-resize-partial-installation-releases-earlier-phase-advice ()
+  "Instrumentation setup failure cleans previously installed advice."
+  (etaf-resize-test--with-run
+    (let ((original-add (symbol-function 'advice-add)) (calls 0))
+      (cl-letf (((symbol-function 'advice-add)
+                 (lambda (&rest args)
+                   (if (= 2 (cl-incf calls)) (error "injected install failure")
+                     (apply original-add args)))))
+        (should-error
+         (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20
+                                     :phases '(ebox-viewport-window-width ebox-surface-buffer-revision)
+                                     :output output)))
+      (should-not ebox-resize-benchmark--run)
+      (let (remaining)
+        (advice-mapc (lambda (_fn _props) (setq remaining t)) 'ebox-viewport-window-width)
+        (should-not remaining)))))
+
+(ert-deftest etaf-resize-mismatched-viewport-cannot-count-as-publication ()
+  "A call returning normally is insufficient when published geometry differs."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (should (eq :real-result
+                (ebox-resize-benchmark--publication (lambda (&rest _) :real-result)
+                                                    buffer (1+ width) 24)))
+    (should-not (plist-get ebox-resize-benchmark--last-result :valid))
+    (should (= 0 (plist-get ebox-resize-benchmark--last-result :completed-count)))))
+
+(ert-deftest etaf-resize-writer-refuses-existing-evidence ()
+  "A later invocation must not silently overwrite a previous report."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark--write output '(:original t))
+    (should-error (ebox-resize-benchmark--write output '(:replacement t)))
+    (with-temp-buffer
+      (insert-file-contents output)
+      (should (equal '(:original t) (read (current-buffer)))))))
+
+(ert-deftest etaf-resize-nested-publication-counts-only-the-outer-call ()
+  "Nested public calls belong to the same measured viewport request."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (should
+     (eq :outer
+         (ebox-resize-benchmark--publication
+          (lambda (&rest _)
+            (ebox-resize-benchmark--publication #'ignore buffer width 24)
+            :outer)
+          buffer width 24)))
+    (should (= 1 (length (plist-get ebox-resize-benchmark--run :samples))))
+    (should (timerp (plist-get ebox-resize-benchmark--run :timer)))))
+
+(ert-deftest etaf-resize-successful-coverage-without-written-evidence-fails ()
+  "Successful calls cannot yield a passed tool result if evidence was lost."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :step 400 :rounds 1
+                                :delay 10 :timeout 20 :output output)
+    (dotimes (_ (plist-get ebox-resize-benchmark--run :planned-count))
+      (etaf-resize-test--tick)
+      (ebox-resize-benchmark--publication #'ignore buffer width 24))
+    (cl-letf (((symbol-function 'ebox-resize-benchmark--write)
+               (lambda (&rest _) (error "disk failure")))
+              ((symbol-function 'message) #'ignore))
+      (should-error (etaf-resize-test--tick)))
+    (should-not ebox-resize-benchmark--run)
+    (should (eq 'failed (plist-get ebox-resize-benchmark--last-result :status)))
+    (should-not (plist-get ebox-resize-benchmark--last-result :valid))
+    (should-not (plist-get ebox-resize-benchmark--last-result :within-limit))
+    (should (plist-get ebox-resize-benchmark--last-result :evidence-write-error))))
+
+(ert-deftest etaf-resize-unattributed-call-still-executes-product-once ()
+  "Diagnostic attribution failure must not prevent real application work."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (ebox-resize-benchmark--publication #'ignore buffer width 24)
+    (let ((calls 0))
+      (should (eq :real-result
+                  (ebox-resize-benchmark--publication
+                   (lambda (&rest _) (cl-incf calls) :real-result) buffer width 24)))
+      (should (= calls 1))
+      (should-not ebox-resize-benchmark--run)
+      (should-not (plist-get ebox-resize-benchmark--last-result :valid)))))
+
+(ert-deftest etaf-resize-cancel-from-product-callback-cannot-rearm-run ()
+  "Cancellation inside a publication prevents its old callback from rearming."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (should (eq :real-result
+                (ebox-resize-benchmark--publication
+                 (lambda (&rest _) (ebox-resize-benchmark-cancel) :real-result)
+                 buffer width 24)))
+    (should-not ebox-resize-benchmark--run)
+    (should (eq 'cancelled (plist-get ebox-resize-benchmark--last-result :status)))))
+
+(ert-deftest etaf-resize-old-publication-cannot-reschedule-replacement-run ()
+  "A callback may replace the benchmark; old completion cannot own its timer."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (let (new-run new-timer)
+      (ebox-resize-benchmark--publication
+       (lambda (&rest _)
+         (ebox-resize-benchmark-cancel)
+         (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20
+                                     :output (expand-file-name "new.eldata" directory))
+         (setq new-run ebox-resize-benchmark--run
+               new-timer (plist-get new-run :timer)))
+       buffer width 24)
+      (should (eq new-run ebox-resize-benchmark--run))
+      (should (eq new-timer (plist-get new-run :timer)))
+      (should-not (plist-get new-run :samples)))))
+
+(ert-deftest etaf-resize-publication-boundary-detects-transient-focus-loss ()
+  "Losing focus before publication invalidates it even if the call restores it."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (let (focused)
+      (cl-letf (((symbol-function 'ebox-resize-benchmark--guard)
+                 (lambda () (unless focused (error "lost focus")))))
+        (should (eq :real-result
+                    (ebox-resize-benchmark--publication
+                     (lambda (&rest _) (setq focused t) :real-result) buffer width 24))))
+      (should-not ebox-resize-benchmark--run)
+      (should-not (plist-get ebox-resize-benchmark--last-result :valid)))))
+
+(ert-deftest etaf-resize-blocking-publication-cannot-hide-expired-deadline ()
+  "Completion must check the deadline even if the event loop could not poll it."
+  (etaf-resize-test--with-run
+    (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+    (etaf-resize-test--tick)
+    (setf (plist-get (plist-get ebox-resize-benchmark--run :current) :requested-at)
+          (- (float-time) 30))
+    (should (eq :real-result
+                (ebox-resize-benchmark--publication (lambda (&rest _) :real-result)
+                                                    buffer width 24)))
+    (should-not ebox-resize-benchmark--run)
+    (should-not (plist-get ebox-resize-benchmark--last-result :valid))
+    (should (> (plist-get (car (plist-get ebox-resize-benchmark--last-result :samples))
+                          :request-to-published-ms) 20000))))
+
+(ert-deftest etaf-resize-code-evidence-includes-every-reload-and-the-driver ()
+  "Explicitly loaded modules need evidence even without a sentinel function."
+  (let* ((directory (make-temp-file "etaf-resize-code-" t))
+         (source (expand-file-name "etaf-resize-evidence-fixture.el" directory))
+         (compiled (concat source "c"))
+         (features (copy-sequence features)))
+    (unwind-protect
+        (progn
+          (with-temp-file source
+            (insert ";;; -*- lexical-binding: t; -*-\n"
+                    "(provide 'etaf-resize-evidence-fixture)\n"))
+          (should (byte-compile-file source))
+          (let* ((code (ebox-resize-benchmark--code (list compiled)))
+                 (reload (car (plist-get code :reload-files)))
+                 (driver (cl-find 'ebox-resize-benchmark-start (plist-get code :functions)
+                                  :key (lambda (entry) (plist-get entry :function)))))
+            (should (featurep 'etaf-resize-evidence-fixture))
+            (should (equal (plist-get reload :file) (file-truename compiled)))
+            (should (plist-get reload :loaded))
+            (should (equal (plist-get reload :sha256)
+                           (ebox-resize-benchmark--hash-file compiled)))
+            (should (equal (plist-get reload :source-sha256)
+                           (ebox-resize-benchmark--hash-file source)))
+            (should (plist-get driver :origin-sha256))))
+      (delete-directory directory t))))
+
+(ert-deftest etaf-resize-start-waits-for-existing-gc-lease-without-measuring-it ()
+  "A preceding render must settle before recording the benchmark baseline."
+  (etaf-resize-test--with-run
+    (let ((ebox--deferred-render-gc-state '(:busy t))
+          (gc-cons-threshold (* 128 1024 1024))
+          (gc-cons-percentage .1))
+      (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+      (etaf-resize-test--tick)
+      (should-not (plist-get ebox-resize-benchmark--run :samples))
+      (should (= width 600))
+      (should (eq :prior-render
+                  (ebox-resize-benchmark--publication
+                   (lambda (&rest _) :prior-render) buffer width 24)))
+      (setq ebox--deferred-render-gc-state nil gc-cons-threshold (* 16 1024 1024))
+      (etaf-resize-test--tick)
+      (should (plist-get ebox-resize-benchmark--run :armed))
+      (should (= width 400))
+      (should (equal (plist-get ebox-resize-benchmark--run :gc-policy)
+                     (list gc-cons-threshold gc-cons-percentage))))))
+
+(ert-deftest etaf-resize-startup-lease-wait-is-bounded ()
+  "A stuck preceding render fails without issuing a benchmark resize."
+  (etaf-resize-test--with-run
+    (let ((ebox--deferred-render-gc-state '(:busy t)))
+      (ebox-resize-benchmark-start buffer 400 800 :delay 10 :timeout 20 :output output)
+      (setf (plist-get ebox-resize-benchmark--run :ready-deadline) (1- (float-time)))
+      (should-error (etaf-resize-test--tick))
+      (should (= width 600))
+      (should-not ebox-resize-benchmark--run)
+      (should-not (plist-get ebox-resize-benchmark--last-result :valid))
+      (should (= 0 (plist-get ebox-resize-benchmark--last-result :requested-count))))))
+
+(ert-deftest etaf-resize-phase-selection-rejects-the-measurement-machinery ()
+  "Instrumentation cannot recursively time its own clock and bookkeeping."
+  (etaf-resize-test--with-run
+    (dolist (phase '(float-time gethash ebox-resize-benchmark--payload
+                               ebox-rerender-buffer-with-context))
+      (should-error (ebox-resize-benchmark-start buffer 400 800
+                                                :phases (list phase) :output output)))
+    (should-not ebox-resize-benchmark--run)
+    (should-not (file-exists-p output))))
+
+(provide 'etaf-resize-benchmark-tests)
+;;; etaf-resize-benchmark-tests.el ends here