Making WebIDL generation deterministic (#2101)

* Making webidl generation deterministic

* Fixing line endings

* Regenerating WebIDL

* Running rustfmt

Author: Pauan

crates/web-sys/src/features/gen_Navigator.rs

@@ -105,18 +105,6 @@ extern "C" {
     #[doc = "*This API requires the following crate features to be activated: `CredentialsContainer`, `Navigator`*"]
     pub fn credentials(this: &Navigator) -> CredentialsContainer;
     #[cfg(web_sys_unstable_apis)]
-    #[cfg(feature = "Xr")]
-    # [ wasm_bindgen ( structural , method , getter , js_class = "Navigator" , js_name = xr ) ]
-    #[doc = "Getter for the `xr` field of this object."]
-    #[doc = ""]
-    #[doc = "[MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/xr)"]
-    #[doc = ""]
-    #[doc = "*This API requires the following crate features to be activated: `Navigator`, `Xr`*"]
-    #[doc = ""]
-    #[doc = "*This API is unstable and requires `--cfg=web_sys_unstable_apis` to be activated, as"]
-    #[doc = "[described in the `wasm-bindgen` guide](https://rustwasm.github.io/docs/wasm-bindgen/web-sys/unstable-apis.html)*"]
-    pub fn xr(this: &Navigator) -> Xr;
-    #[cfg(web_sys_unstable_apis)]
     #[cfg(feature = "Gpu")]
     # [ wasm_bindgen ( structural , method , getter , js_class = "Navigator" , js_name = gpu ) ]
     #[doc = "Getter for the `gpu` field of this object."]
@@ -128,6 +116,18 @@ extern "C" {
     #[doc = "*This API is unstable and requires `--cfg=web_sys_unstable_apis` to be activated, as"]
     #[doc = "[described in the `wasm-bindgen` guide](https://rustwasm.github.io/docs/wasm-bindgen/web-sys/unstable-apis.html)*"]
     pub fn gpu(this: &Navigator) -> Gpu;
+    #[cfg(web_sys_unstable_apis)]
+    #[cfg(feature = "Xr")]
+    # [ wasm_bindgen ( structural , method , getter , js_class = "Navigator" , js_name = xr ) ]
+    #[doc = "Getter for the `xr` field of this object."]
+    #[doc = ""]
+    #[doc = "[MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/xr)"]
+    #[doc = ""]
+    #[doc = "*This API requires the following crate features to be activated: `Navigator`, `Xr`*"]
+    #[doc = ""]
+    #[doc = "*This API is unstable and requires `--cfg=web_sys_unstable_apis` to be activated, as"]
+    #[doc = "[described in the `wasm-bindgen` guide](https://rustwasm.github.io/docs/wasm-bindgen/web-sys/unstable-apis.html)*"]
+    pub fn xr(this: &Navigator) -> Xr;
     # [ wasm_bindgen ( structural , method , getter , js_class = "Navigator" , js_name = hardwareConcurrency ) ]
     #[doc = "Getter for the `hardwareConcurrency` field of this object."]
     #[doc = ""]

crates/webidl/src/lib.rs

@@ -25,7 +25,7 @@ use crate::generator::{
 use crate::idl_type::ToIdlType;
 use crate::traverse::TraverseType;
 use crate::util::{
-    camel_case_ident, is_structural, shouty_snake_case_ident, snake_case_ident, throws,
+    camel_case_ident, is_structural, read_dir, shouty_snake_case_ident, snake_case_ident, throws,
     webidl_const_v_to_backend_const_v, TypePosition,
 };
 use anyhow::Context;
@@ -749,11 +749,9 @@ pub fn generate(from: &Path, to: &Path, options: Options) -> Result<String> {
 
     /// Read all WebIDL files in a directory into a single `SourceFile`
     fn read_source_from_path(dir: &Path) -> Result<SourceFile> {
-        let entries = fs::read_dir(dir).context("reading webidls directory")?;
+        let entries = read_dir(dir).context("reading webidls directory")?;
         let mut source = SourceFile::default();
-        for entry in entries {
-            let entry = entry.context(format!("getting {}/*.webidl entry", dir.display()))?;
-            let path = entry.path();
+        for path in entries {
             if path.extension() != Some(OsStr::new("webidl")) {
                 continue;
             }

crates/webidl/src/util.rs

@@ -1,5 +1,7 @@
 use std::collections::BTreeSet;
+use std::fs;
 use std::iter::FromIterator;
+use std::path::{Path, PathBuf};
 use std::ptr;
 
 use heck::{CamelCase, ShoutySnakeCase, SnakeCase};
@@ -23,6 +25,21 @@ use crate::Options;
 /// in their names, where `n` is this constant.
 const MAX_VARIADIC_ARGUMENTS_COUNT: usize = 7;
 
+/// Similar to std::fs::read_dir except it returns a sorted Vec,
+/// which is important to make the code generation deterministic.
+pub(crate) fn read_dir<P>(path: P) -> std::io::Result<Vec<PathBuf>>
+where
+    P: AsRef<Path>,
+{
+    let mut entries = fs::read_dir(path)?
+        .map(|entry| Ok(entry?.path()))
+        .collect::<std::io::Result<Vec<_>>>()?;
+
+    entries.sort();
+
+    Ok(entries)
+}
+
 /// Take a type and create an immutable shared reference to that type.
 pub(crate) fn shared_ref(ty: syn::Type, mutable: bool) -> syn::Type {
     syn::TypeReference {