trustfall_wasm — the WebAssembly version of the trustfall engine

Embed state-of-the-art query capabilities directly into the browser, enabling a new generation of local-first serverless applications. Any query a server or serverless hosted function could run can also run at least as well in your own browser.

Browser demo of trustfall_wasm

See the www directory for an end-to-end demo of querying with trustfall_wasm, including an adapter implemented in JavaScript and a schema instantiated from JavaScript.

Building the trustfall_wasm module

Prerequisites:

• a recent Rust environment: installation instructions
• the wasm-pack tool: installation instructions

All following commands are run from the trustfall_wasm directory.

The WASM module currently only supports web browser use, and does not support running in Node. To run browser tests, make sure you have Firefox or Chrome installed, and then run one of the following commands matching the browser you'd like to test in:

wasm-pack test --headless --firefox
wasm-pack test --headless --chrome

The TypeScript definitions file is currently hand-written, since the wasm-bindgen auto-generated definitions are not as detailed (e.g. wouldn't make the Adapter type appropriately generic). Building the WASM module is therefore a two-step process:

• Build the WASM/JS files.
• Copy the hand-written TypeScript definitions into the build directory (by default, pkg).

To create a dev build, run the following commands:

wasm-pack build --dev
cp src/trustfall_wasm.d.ts pkg/

To create a release build, run the following commands:

wasm-pack build
cp src/trustfall_wasm.d.ts pkg/

At the end of either of these scripts, the build directory (by default, pkg) will contain the built WASM module and all its supporting files.