Add synthetic focus/type/click: real DOM events, not attribute pokes - #91
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The actual "drive a login form" API on top of the LiveDocument foundation (#89) and hit-testing (#90). js/events.go: dispatch now bubbles — fires target-phase listeners on the node, then (when event.bubbles is true and nothing called stopPropagation) walks up the ancestor chain doing the same, updating target/currentTarget as it goes. Distinguishes stopPropagation (later listeners on the SAME node still run) from stopImmediatePropagation (they don't), which a single flag would have blurred. This is a behavior change to a function every existing page script's click()/ dispatchEvent() call already goes through — verified against the full existing test suite (unaffected: real content bubbles=false by default, matching spec) before adding anything on top. js/session.go: Session.Dispatch(n, typ, EventInit) is the new Go-facing seam — fires a synthetic event exactly as if the page's own script had called element.dispatchEvent(), and reports defaultPrevented so a caller (native form submission, a later phase) can honor it. synthetic.go (engine package): LiveDocument.Focus/Blur/Type/Click compose real event sequences through that seam — Type fires keydown->input->keyup PER CHARACTER (not one bulk value assignment), which is what lets a controlled React/Vue onChange see every keystroke; Focus/Blur track which control is focused and fire change only when its value actually differs at blur, matching real browser semantics; Click does mousedown->mouseup->click and reports defaultPrevented. Each interaction resettles (F0) so the live session keeps running, not restarting. TestSyntheticLoginFlow is the decisive end-to-end proof: a login form whose JS accumulates typed text in its OWN closure variables (not just DOM attributes) across many separate Focus/Type/Click calls, only succeeding once both fields match — exactly the shape a real login page's JS takes, and exactly what a naive re-render-per-keystroke would have silently corrupted. 100% coverage on every new/changed function, full existing suite + -race unaffected. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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F4 of the interactive-form-input plan (#89-#91): the path for a plain server-rendered login form with no JS submit handler at all. LiveDocument.Submit(ctx, form) dispatches "submit" through the live session first, exactly like a real browser. If a listener calls preventDefault() (the common SPA case, already reachable via Focus/Type/Click plus the engine's existing fetch()/XHR support), nothing further happens and the current page stays open. Otherwise it gathers named form-control values (input/textarea/select, skipping disabled controls and unchecked checkboxes/radios, matching what a real browser submits) and performs the actual GET-with-querystring or POST-urlencoded request per the form's action/method, then opens the response as a new LiveDocument and closes the old one — a real navigation ending the previous page's JS, same as a browser. Caught two real gaps while writing this against the actual DOM model rather than assuming: <select>'s submitted value needs its own selected-option walk (no shared helper existed at the engine-package level); <textarea> has no dedicated JS value accessor (js/dom.go's generic "value" property just reads the "value" attribute, which a textarea doesn't carry until something explicitly sets it) — Submit's own value-gathering falls back to the element's text content for an untouched textarea, matching what a real browser's textarea.value defaults to, while documenting the JS-binding gap for anyone who hits it from script instead. 100% coverage on every function except postForm (83.3% — the remaining gaps are low-level I/O failure branches http.NewRequest/ ReadAll/decodeCharset/dom.Parse can each return, consistent with this codebase's own existing tolerance for that class of near-unreachable path: Fetch and decodeCharset sit at 82.4%/75% on main today for the same reason). Full existing suite + -race unaffected. Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
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Summary
The actual "drive a login form" API, on top of the
LiveDocumentfoundation (#89) and hit-testing (#90).js/events.go:dispatchnow bubbles — target-phase listeners on the node, then (whenevent.bubblesand nothing calledstopPropagation) up the ancestor chain, updatingtarget/currentTargetas it goes. DistinguishesstopPropagation(later listeners on the SAME node still run) fromstopImmediatePropagation(they don't). This is a behavior change to a function every existing page script's.click()/dispatchEvent()already goes through — verified against the full existing suite before building anything on top (unaffected: real content defaultsbubbles=false, matching spec).js/session.go:Session.Dispatch(n, typ, EventInit)— the Go-facing seam, firing a synthetic event exactly as if the page's own script had calledelement.dispatchEvent(), reportingdefaultPrevented.synthetic.go:LiveDocument.Focus/Blur/Type/Click.Typefireskeydown→input→keyupper character (not one bulk value assignment) — what lets a controlled React/VueonChangesee every keystroke.Focus/Blurtrack the focused control and firechangeonly when its value actually differs at blur.Clickdoesmousedown→mouseup→clickand reportsdefaultPrevented.Test plan
-racepass unmodified,go vet/gofmtclean, 100% coverage on every new/changed functionTestSyntheticLoginFlow— the decisive proof: a login form whose JS accumulates typed text in its own closure variables (not just DOM attributes) across many separateFocus/Type/Clickcalls, only succeeding once both fields match. This is exactly what a naive re-render-per-keystroke would have silently corrupted, and exactly the shape a real login page's JS takes.TestEventBubbling/TestStopPropagationVsStopImmediate/TestEventCurrentTargetTracksBubblePhase— the bubbling mechanics in isolationTestFocusFiresBlurAndChangeOnThePreviousField— the blur/change fallout when focus moves🤖 Generated with Claude Code