Found by the PR review, each with a test that failed first:
- get_diagram during a page export returned the one-page projection on
screen as the whole document (6 of 6 times when timed so). The preview
page no longer answers a sync while a projection shows, and syncs after
reloading, so the poll that restores the real document exports it.
- Exports are numbered on the server too: a late result of an export that
timed out was saved as the next export's file.
- In Chrome, a new_xml with a syntax error counted the <parsererror>
element as a second cell, so the web app rejected edits that auto-fix
repairs ("must contain exactly one cell").
- hasCells missed single-quoted ids, so screenshot_diagram called such a
diagram empty and auto-save never created its file.
- A literal \n directly under a <diagram> that has a model passed
validation; only text-only pages are compressed data.
- A wrapped mxCell repeating its UserObject's id took the wrapper's place
in edits, so delete and update left an empty or nested wrapper.
- Bare cells with a shape or edge id of "0" or "1" are rejected with a
clear message instead of being renamed, which broke their edges.
- DRAWIO_DATA_DIR expands ~, which JSON configs pass on as it is.
draw.io reads any text inside a page as compressed page data, so a stray
text node makes the whole page fail with an atob error. gpt-5-mini sends
new cells with a literal "\n" between the tags; the edit card said
Complete while draw.io showed the error and kept the old diagram.
Validation now reports text between tags, and auto-fix turns a literal
\n, \t or \r between tags into whitespace. Other text goes back to the
model as an error. The compressed data directly under <diagram> is fine.
The web app will reuse the MCP server's XML engine instead of its own
copy in lib/utils.ts, so these modules now run in the browser too.
- Relative imports end in .ts, rewritten to .js by tsc
(rewriteRelativeImportExtensions); Next.js resolves them directly
- Every module uses the global DOMParser/XMLSerializer: native in the
browser, linkedom in Node via installDomPolyfill. pages.ts parsed with
linkedom but serialized with the global serializer, which throws in
the browser
- The saxes syntax check moves to xml-syntax.ts, so the browser does not
pull in linkedom; it now also rejects undeclared prefixes such as
xlink:, as the browser does
- Page decompression uses pako and atob instead of node:zlib and Buffer
- hasCells moves to pages.ts, away from the file system code
- The duplicate cell id check counts UserObject/object ids
- wrapCellsInModel drops comments and text before the first cell, which
the web app accepts today
- validateAndFixXml takes { strict: false } for diagrams with user content
- Web tests run these modules with a browser DOM (jsdom)
- saxes becomes a direct dependency of the web app
- Preview page: keep an MCP export open until the server has its result.
A poll answered before that still saw the request and started the same
export again, so a parallel page export could write the previous
page's image into its file
- Auto-save only removes its own mcp-*.drawio files, so a DRAWIO_DATA_DIR
that also holds the user's diagrams keeps them
- screenshot_diagram captures a page that has no id attribute by loading
just that page, like export_diagram
- An empty <Array as="points"/> no longer hides orphan mxPoints that
come after it
- POST /api/state refuses a push without xml, which used to wipe the
stored diagram
- Clear exportOptions when an export ends, reuse hasCells for the empty
diagram check, and reword two log lines
- edit_diagram applies nothing when any operation fails, rejects invalid or
multi-cell new_xml, validates only the target page, and returns the
current page XML on every rejection (including stale edits)
- Fix get_diagram reading the old diagram right after an AI write: the
preview pushed its sync reply with a newer version than it was taken at
- Keep a user edit that loses the race with an AI write in history and
tell the user in the preview
- Autofix removes only exact foreign tags (a stray <mxGraph/> deleted
<mxGraphModel>), fixes tag case, drops orphan <mxPoint>s, and rejects
unknown element names in model XML
- Edit empty and compressed pages; PNG exports use the page on screen;
tag download exports; reload from the server after a page export
- Expand ~ in paths, tell the model when the browser sync timed out,
use registerPrompt, require SDK ^1.31.0
- Validate and escape the mcp session id; only serve localhost Host/Origin
- Malformed URLs and session ids return errors instead of crashing the process
- Strict XML syntax check with saxes (linkedom never reports parse errors)
- autoFixXml no longer corrupts valid XML; attribute newlines serialized as entities
- Sessions stay alive while polled; browser pushes carry a base version (409 on conflict)
- Page tools respect the edit gate; UTF-8 bodies decoded correctly
- Export replies matched to requests and serialized; xml sync export handled
- UserObject/object cells addressable by id; history restored by stable id; logs off stdout
dayuan.jiang