From 79279ad8cf7615d583ae19520d4de1b05477d346 Mon Sep 17 00:00:00 2001 From: Alistair Date: Tue, 7 Nov 2023 10:33:58 +0000 Subject: [PATCH] Update `[[HostDefined]]` example. --- boa_examples/src/bin/host_defined.rs | 67 ++++++++++++++++++++++------ 1 file changed, 53 insertions(+), 14 deletions(-) diff --git a/boa_examples/src/bin/host_defined.rs b/boa_examples/src/bin/host_defined.rs index c60d4c4dcfb..69399f0cf1d 100644 --- a/boa_examples/src/bin/host_defined.rs +++ b/boa_examples/src/bin/host_defined.rs @@ -1,7 +1,8 @@ // This example goes into the details on how to store user defined structs/state that is shared. use boa_engine::{ - js_string, native_function::NativeFunction, Context, JsArgs, JsError, JsNativeError, Source, + js_string, native_function::NativeFunction, Context, JsArgs, JsError, JsNativeError, JsValue, + Source, }; use boa_gc::{Finalize, Trace}; @@ -25,6 +26,13 @@ impl AnotherCustomHostDefinedStruct { } } +/// Custom host-defined struct that tracks the number of calls to the `getRealmValue` and `setRealmValue` functions. +#[derive(Default, Trace, Finalize)] +struct HostDefinedMetrics { + #[unsafe_ignore_trace] + counter: usize, +} + fn main() -> Result<(), JsError> { // We create a new `Context` to create a new Javascript executor.. let mut context = Context::default(); @@ -34,14 +42,15 @@ fn main() -> Result<(), JsError> { // Insert a default CustomHostDefinedStruct. realm - .host_defined() + .host_defined_mut() .insert_default::(); { assert!(realm.host_defined().has::()); // Get the [[HostDefined]] field from the realm and downcast it to our concrete type. - let Some(host_defined) = realm.host_defined().get::() else { + let host_defined = realm.host_defined(); + let Some(host_defined) = host_defined.get::() else { return Err(JsNativeError::typ() .with_message("Realm does not have HostDefined field") .into()); @@ -53,15 +62,15 @@ fn main() -> Result<(), JsError> { // Insert another struct with state into [[HostDefined]] field. realm - .host_defined() + .host_defined_mut() .insert(AnotherCustomHostDefinedStruct::new(10)); { assert!(realm.host_defined().has::()); // Get the [[HostDefined]] field from the realm and downcast it to our concrete type. - let Some(host_defined) = realm.host_defined().get::() - else { + let host_defined = realm.host_defined(); + let Some(host_defined) = host_defined.get::() else { return Err(JsNativeError::typ() .with_message("Realm does not have HostDefined field") .into()); @@ -73,7 +82,7 @@ fn main() -> Result<(), JsError> { // Remove a type from the [[HostDefined]] field. assert!(realm - .host_defined() + .host_defined_mut() .remove::() .is_some()); @@ -86,14 +95,17 @@ fn main() -> Result<(), JsError> { NativeFunction::from_fn_ptr(|_, args, context| { let value: usize = args.get_or_undefined(0).try_js_into(context)?; - let host_defined = context.realm().host_defined(); - let Some(mut host_defined) = host_defined.get_mut::() else { + let mut host_defined = context.realm().host_defined_mut(); + let Some((host_defined, metrics)) = + host_defined.get_many_mut::<(CustomHostDefinedStruct, HostDefinedMetrics), 2>() + else { return Err(JsNativeError::typ() .with_message("Realm does not have HostDefined field") .into()); }; host_defined.counter = value; + metrics.counter += 1; Ok(value.into()) }), @@ -103,17 +115,34 @@ fn main() -> Result<(), JsError> { js_string!("getRealmValue"), 0, NativeFunction::from_fn_ptr(|_, _, context| { - let host_defined = context.realm().host_defined(); - let Some(host_defined) = host_defined.get::() else { + let mut host_defined = context.realm().host_defined_mut(); + + let value: JsValue = { + let Some(host_defined) = host_defined.get::() else { + return Err(JsNativeError::typ() + .with_message("Realm does not have HostDefined field") + .into()); + }; + host_defined.counter.into() + }; + + let Some(metrics) = host_defined.get_mut::() else { return Err(JsNativeError::typ() .with_message("Realm does not have HostDefined field") .into()); }; - Ok(host_defined.counter.into()) + metrics.counter += 1; + + Ok(value) }), )?; + // Insert HostDefinedMetrics into the [[HostDefined]] field. + realm + .host_defined_mut() + .insert_default::(); + // Run code in JavaScript that mutates the host-defined field on the Realm. context.eval(Source::from_bytes( r" @@ -122,14 +151,24 @@ fn main() -> Result<(), JsError> { ", ))?; - let Some(host_defined) = realm.host_defined().get::() else { + let host_defined = realm.host_defined(); + let Some(host_defined_value) = host_defined.get::() else { return Err(JsNativeError::typ() .with_message("Realm does not have HostDefined field") .into()); }; // Assert that the host-defined field changed. - assert_eq!(host_defined.counter, 100); + assert_eq!(host_defined_value.counter, 100); + + let Some(metrics) = host_defined.get::() else { + return Err(JsNativeError::typ() + .with_message("Realm does not have HostDefined field") + .into()); + }; + + // Assert that we called the getRealmValue and setRealmValue functions (3 times in total) + assert_eq!(metrics.counter, 3); Ok(()) }