deno/cli/js.rs
Nayeem Rahman c1c8eb3d55
build: allow disabling snapshots for dev (#20048)
Closes #19399 (running without snapshots at all was suggested as an
alternative solution).

Adds a `__runtime_js_sources` pseudo-private feature to load extension
JS sources at runtime for faster development, instead of building and
loading snapshots or embedding sources in the binary. Will only work in
a development environment obviously.

Try running `cargo test --features __runtime_js_sources
integration::node_unit_tests::os_test`. Then break some behaviour in
`ext/node/polyfills/os.ts` e.g. make `function cpus() {}` return an
empty array, and run it again. Fix and then run again. No more build
time in between.
2023-08-06 01:47:15 +02:00

43 lines
967 B
Rust

// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
use deno_core::Snapshot;
use log::debug;
#[cfg(not(feature = "__runtime_js_sources"))]
static CLI_SNAPSHOT: &[u8] =
include_bytes!(concat!(env!("OUT_DIR"), "/CLI_SNAPSHOT.bin"));
pub fn deno_isolate_init() -> Option<Snapshot> {
debug!("Deno isolate init with snapshots.");
#[cfg(not(feature = "__runtime_js_sources"))]
{
Some(Snapshot::Static(CLI_SNAPSHOT))
}
#[cfg(feature = "__runtime_js_sources")]
{
None
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn runtime_snapshot() {
let mut js_runtime = deno_core::JsRuntime::new(deno_core::RuntimeOptions {
startup_snapshot: deno_isolate_init(),
..Default::default()
});
js_runtime
.execute_script_static(
"<anon>",
r#"
if (!(bootstrap.mainRuntime && bootstrap.workerRuntime)) {
throw Error("bad");
}
"#,
)
.unwrap();
}
}