The envelope of EffectCraft .ecproj project files: the members around the project that EffectCraft writes and other apps read. The project model, the saved view and the schema 1 conversion stay in EffectCraft. No unsafe, no panics, and it builds for wasm32-unknown-unknown. The dependencies are serde, serde_json and thiserror.

craft-ecproj-format = { git = "https://github.com/storytold/craft-libs", rev = "<commit>" }

The file

A project file is one UTF-8 JSON object with no newline at the end: savedBy, then the saved view's members (activeComp, openComps, compTimes, each left out when empty), then the project's members, starting with schema. Projects saved before savedBy was added start with schema. EffectCraft indents the object with two spaces, or writes it on one line when Settings ▸ Project ▸ Save Compact Project Files is on. The crate writes and reads both forms.

Use

use craft_ecproj_format::{File, Head, check_schema};

// Writing
check_schema(project.schema)?;
let text = File::new(APP_VERSION, &view, &project).to_json()?;

// Reading
let head = Head::read(&text)?;

SCHEMA_VERSION is the newest project schema, 2.
check_schema(schema) -> Result<(), TooNew> refuses a schema newer than SCHEMA_VERSION. TooNew reads "project schema 3 is newer than this version supports (2)". It is #[non_exhaustive]: other crates read its schema and supported fields.
File { saved_by, view, project } serializes as one object, with view and project flattened into it. to_json() gives the file's text indented with two spaces, and to_json_compact() gives it on one line. Neither checks the values: serde_json writes NaN and infinity as null, so the caller checks its values before saving.
Head::read_from(reader) applies the same header parsing to a std::io::Read, allowing a caller to bound or interrupt input. File/network readers should be buffered.
Head::read(text) -> Result<Head, ReadError> reads savedBy and schema from one JSON object, and skips other members. savedBy is None when it is absent, is not a string, or appears more than once. Text that is not a JSON object, has no schema that is a u32, or has two schema members gives ReadError::Json. A schema newer than SCHEMA_VERSION gives ReadError::TooNew { too_new, saved_by, .. }, which reads as TooNew does and holds the file's savedBy, so a message can name the version that wrote it. ReadError and its TooNew variant are #[non_exhaustive]: match them with a wildcard arm and ...

.ecprojx files hold the same object encoded as XML, which this crate does not read or write.