fix(core): Fixes loading file on windows

When we were loading the file, we were locking it and then opening another
file handle to read it. The test was loading it readonly rather than
using a shared lock, so this didn't catch the edge case

Signed-off-by: Taylor Thomas <[email protected]>

Author: thomastaylor312

Cargo.lock

@@ -4,7 +4,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-version = "0.8.2"
+version = "0.8.3"
 authors = ["The Wasmtime Project Developers"]
 license = "Apache-2.0 WITH LLVM-exception"
 
@@ -36,9 +36,9 @@ tracing-subscriber = { version = "0.3.18", default-features = false, features =
     "fmt",
     "env-filter",
 ] }
-wasm-pkg-common = { version = "0.8.2", path = "crates/wasm-pkg-common" }
-wasm-pkg-client = { version = "0.8.2", path = "crates/wasm-pkg-client" }
+wasm-pkg-common = { version = "0.8.3", path = "crates/wasm-pkg-common" }
+wasm-pkg-client = { version = "0.8.3", path = "crates/wasm-pkg-client" }
 wasm-metadata = "0.219"
 wit-component = "0.219"
 wit-parser = "0.219"
-wasm-pkg-core = { version = "0.8.2", path = "crates/wasm-pkg-core" }
+wasm-pkg-core = { version = "0.8.3", path = "crates/wasm-pkg-core" }

Cargo.toml

@@ -12,7 +12,7 @@ use semver::{Version, VersionReq};
 use serde::{Deserialize, Serialize};
 use tokio::{
     fs::{File, OpenOptions},
-    io::{AsyncSeekExt, AsyncWriteExt},
+    io::{AsyncReadExt, AsyncSeekExt, AsyncWriteExt},
 };
 use wasm_pkg_client::{ContentDigest, PackageRef};
 
@@ -70,12 +70,14 @@ impl LockFile {
     /// Loads a lock file from the given path. If readonly is set to false, then an exclusive lock
     /// will be acquired on the file. This function will block until the lock is acquired.
     pub async fn load_from_path(path: impl AsRef<Path>, readonly: bool) -> Result<Self> {
-        let locker = if readonly {
+        let mut locker = if readonly {
             Locker::open_ro(path.as_ref()).await
         } else {
             Locker::open_rw(path.as_ref()).await
         }?;
-        let contents = tokio::fs::read_to_string(path)
+        let mut contents = String::new();
+        locker
+            .read_to_string(&mut contents)
             .await
             .context("unable to load lock file from path")?;
         let lock_file: LockFileIntermediate =
@@ -87,6 +89,13 @@ impl LockFile {
                 lock_file.version
             ));
         }
+        // Rewind the file after reading just to be safe. We already do this before writing, but
+        // just in case we add any future logic, we can reset the file here so as to not cause
+        // issues
+        locker
+            .rewind()
+            .await
+            .context("Unable to reset file after reading")?;
         Ok(lock_file.into_lock_file(locker))
     }
 
@@ -131,25 +140,24 @@ impl LockFile {
     pub async fn write(&mut self) -> Result<()> {
         let contents = toml::to_string_pretty(self)?;
         // Truncate the file before writing to it
-        self.locker.file.rewind().await.with_context(|| {
+        self.locker.rewind().await.with_context(|| {
             format!(
                 "unable to rewind lock file at path {}",
                 self.locker.path.display()
             )
         })?;
-        self.locker.file.set_len(0).await.with_context(|| {
+        self.locker.set_len(0).await.with_context(|| {
             format!(
                 "unable to truncate lock file at path {}",
                 self.locker.path.display()
             )
         })?;
 
-        self.locker.file.write_all(
+        self.locker.write_all(
             b"# This file is automatically generated.\n# It is not intended for manual editing.\n",
         )
         .await.with_context(|| format!("unable to write lock file to path {}", self.locker.path.display()))?;
         self.locker
-            .file
             .write_all(contents.as_bytes())
             .await
             .with_context(|| {
@@ -160,7 +168,7 @@ impl LockFile {
             })?;
         // Make sure to flush and sync just to be sure the file doesn't drop and the lock is
         // released too early
-        self.locker.file.sync_all().await.with_context(|| {
+        self.locker.sync_all().await.with_context(|| {
             format!(
                 "unable to write lock file to path {}",
                 self.locker.path.display()
@@ -860,7 +868,7 @@ mod tests {
 
         // Now read the lock file again and make sure everything is correct (and we can lock it
         // properly)
-        let lock = LockFile::load_from_path(&path, true)
+        let lock = LockFile::load_from_path(&path, false)
             .await
             .expect("Shouldn't fail when loading lock file");
         assert_eq!(