fix: use channel key not version from rust-toolchain.toml (#304)

* fix(rust): pull version from channel, not version field

fixes #296

* test: use correct rust-toolchain.toml channel key

* docs: update rust version specification docs

* refactor: inline ifs

* test: assert against mise-specified rust version

* test: update snapshot

core/__snapshots__/TestGenerateBuildPlanForExamples_rust-cargo-workspaces-glob_1.snap.json

@@ -38,6 +38,10 @@
     {
      "path": "/mise/shims"
     },
+    {
+     "dest": ".tool-versions",
+     "src": ".tool-versions"
+    },
     {
      "customName": "create mise config",
      "name": "mise.toml",

core/providers/rust/rust.go

@@ -330,20 +330,28 @@ func (p *RustProvider) InstallMisePackages(ctx *generate.GenerateContext, miseSt
 		}
 	}
 
-	if cargoToml != nil {
-		if cargoToml.Package.RustVersion != "" {
-			// Newer versions of Rust allow the `rust-version` field in Cargo.toml
-			if version := utils.ExtractSemverVersion(cargoToml.Package.RustVersion); version != "" {
-				miseStep.Version(rust, version, "Cargo.toml")
-			}
+	if cargoToml != nil && cargoToml.Package.RustVersion != "" {
+		// Newer versions of Rust allow the `rust-version` field in Cargo.toml
+		if version := utils.ExtractSemverVersion(cargoToml.Package.RustVersion); version != "" {
+			miseStep.Version(rust, version, "Cargo.toml")
 		}
 	}
 
 	if toolchain, err := parseRustToolchain(ctx); err == nil {
-		if version := utils.ExtractSemverVersion(toolchain.Toolchain.Version); version != "" {
+		versionSource := toolchain.Toolchain.Channel
+		// TODO: Remove support for deprecated Version field in a future release
+		if toolchain.Toolchain.Version != "" {
+			ctx.Logger.LogWarn("The 'version' field in rust-toolchain.toml is deprecated and will be removed in a future release. Please use 'channel' instead.")
+			if versionSource == "" {
+				versionSource = toolchain.Toolchain.Version
+			}
+		}
+		if version := utils.ExtractSemverVersion(versionSource); version != "" {
 			miseStep.Version(rust, version, "rust-toolchain.toml")
 		}
 	}
+
+	miseStep.UseMiseVersions(ctx, []string{"rust"})
 }
 
 var wasmRegex = regexp.MustCompile(`target\s*=\s*"wasm32-wasi"`)

docs/src/content/docs/languages/rust.md

@@ -15,12 +15,13 @@ Your project will be detected as a Rust application if any of these conditions a
 
 The Rust version is determined in the following order:
 
-- Set via the `package.edition` field in the `Cargo.toml` file
-- Set via the `RAILPACK_RUST_VERSION` environment variable
-- Read from the `.rust-version` or `rust-version.txt` file
+- Any mise-supported version file (`mise.toml`, `.tool-versions`, etc).
+- Read from the `toolchain.channel` field in the `rust-toolchain.toml` file
 - Read from the `package.rust-version` field in the `Cargo.toml` file
-- Read from the `toolchain.version` field in the `rust-toolchain.toml` file
-- Defaults to `1.85.1`
+- Read from the `.rust-version` or `rust-version.txt` file
+- Set via the `RAILPACK_RUST_VERSION` environment variable
+- Set via the `package.edition` field in the `Cargo.toml` file
+- Defaults to `1.89`
 
 ## Runtime Variables
 

examples/rust-cargo-workspaces-glob/.tool-versions

@@ -0,0 +1 @@
+rust 1.88.0

examples/rust-cargo-workspaces-glob/test.json

@@ -1,5 +1,5 @@
 [
   {
-    "expectedOutput": "Hello from rust (rustc 1.89.0)"
+    "expectedOutput": "Hello from rust (rustc 1.88.0)"
   }
 ]

examples/rust-custom-toolchain/rust-toolchain.toml

@@ -1,4 +1,3 @@
 [toolchain]
-channel = "nightly-2024-08-12"
-version = "1.59.0"
+channel = "1.59.0"
 profile = "minimal"