An import's instruction and time budgets are now host limits on Limits, as a heavy filter's are, so a test can give an importer a small budget. An importer past its instruction or time limit, and a file past the input limit, return their error and leave an open document and its undo history unchanged. The manifest fuzz varies extensions (missing, dotted, mixed-case, repeated, too long and too many).
A plug-in of the wrong kind now gets "is a plug-in of kind `exporter`, not an importer", with rows in every complete-message catalog. The importer failure test also covers an open, edited document. docs/plugins.md states that Open Recent does not remember Open With's importer or parameters.
An importer plug-in (kind "importer", permission import.read) lists 1 to 8
file extensions and turns a file's bytes into objects, which open as a new
document whose artboard is their bounds. File › Open lists its extensions,
File › Open With (file.openWith) opens a file with a chosen importer, and
document.open takes importer and params. A built-in format that reads the
file by its content or extension always opens it; among importers listing
the same extension, the one whose id sorts first opens it. An importer reads
at most 128 MiB, and Place still reads only the built-in formats.
Docs: docs/plugins.md, docs/mcp.md, docs/gaps.md, docs/target-app-parity.md.
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