Step 7/12 of docs/superpowers/plans/2026-05-17-files-overlay-rewrite.md.
overlay_file_edit_page now renders the binary-replace UI instead of
returning 415 for non-editable files. Two cases bridge to the same
binary template: the up-front is_editable() check and the late-binding
UnicodeDecodeError on read (8-KiB sniff said yes but the tail had
non-UTF-8 bytes). Both paths route through a small _render_binary_editor
helper that fills in:
* is_binary=True
* content="" (no inline editor)
* byte_count=target.stat().st_size
* mime_type from mimetypes.guess_type, falling back to
application/octet-stream
Template (overlay_file_editor.html) gains an is_binary branch in the
modal body: hides .files-editor-text (CM6 textarea + language
dropdown), renders .files-editor-binary instead with file-info note,
replace-zone (drop area + browse button + hidden file input), and
the per-state idle/queued labels. The Save button reads "Replace"
in binary mode and starts disabled — Step 8 enables it via JS when
a replacement file is queued.
Delete and Download stay visible in binary mode (binary files can be
deleted and downloaded the same way text files can).
The /files/new route gets is_binary=False + mime_type="" passed
explicitly so the template's binary branch never fires there.
Server-side only — no JS changes in Step 7. Step 8 wires up the
binary-replace handlers (replace-zone drag, browse/clear clicks,
Replace button → POST /files/replace).
Tests:
* Removed test_edit_route_415s_for_non_editable_file — the route
no longer returns 415 for non-editable files; the binary template
is the new contract.
* Added test_edit_route_renders_binary_template_for_non_editable
(asserts 200 + is_binary markup + Save button label + disabled
state + .files-editor-text absent + byte count rendered).
* Added test_binary_template_has_replace_zone (asserts the replace-
zone markup: drop zone, idle/queued labels, browse button, hidden
file input, and that Download stays visible).
pytest: 578 → 579 passed, 1 skipped, 3 deselected. The pre-existing
"still 404 / still 400" cases the plan asks for are covered by the
existing test_edit_route_404s_for_missing_file and
test_edit_route_400s_for_path_traversal tests — left alone rather
than duplicated.
Verified live: GET /overlays/2/files/edit?path=test.png (an actual
binary file in the demo overlay) returns the binary template; DOM
inspection confirms .files-editor-binary present with data-rel-path,
"Replace" save button starts disabled, Download href points at the
file's download endpoint, MIME type and byte count match, .files-
editor-text is absent.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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