Improved output directory helpers

CHANGELOG.md

@@ -9,11 +9,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `libcnb-package`:
+  - Added the `output::create_packaged_buildpack_dir_resolver` helper which contains all the information on how compiled buildpack directories are structured returns a function that can be invoked with `BuildpackId` to produce the output path for a buildpack. ([#632](https://github.com/heroku/libcnb.rs/pull/632))
+
 ### Changed
 
 - `libcnb-package`:
   - Added `find_cargo_workspace_root_dir` which provides a convenient starting point for locating buildpacks for packaging and testing purposes. ([#629](https://github.com/heroku/libcnb.rs/pull/629))
   - Changed the `ReadBuildpackDataError` and `ReadBuildpackageDataError` enums from struct to tuple format to be consistent with other error enums in the package. ([#631](https://github.com/heroku/libcnb.rs/pull/631))
+  - Changed `buildpack_dependency::rewrite_buildpackage_local_dependencies` to accept a `&BuildpackOutputDirectoryLocator` instead of `&HashMap<&BuildpackId, PathBuf>`. ([#632](https://github.com/heroku/libcnb.rs/pull/632))
+  - Moved `default_buildpack_directory_name` to `output::default_buildpack_directory_name`. ([#632](https://github.com/heroku/libcnb.rs/pull/632))
+
+### Removed
+
+- `libcnb-package`:
+  - `get_buildpack_package_dir` has been removed in favor of `output::create_packaged_buildpack_dir_resolver` for building output paths to compiled buildpacks. ([#632](https://github.com/heroku/libcnb.rs/pull/632))
 
 ## [0.14.0] - 2023-08-18
 

libcnb-cargo/src/package/command.rs

@@ -11,16 +11,25 @@ use libcnb_package::buildpack_dependency::{
 use libcnb_package::buildpack_package::{read_buildpack_package, BuildpackPackage};
 use libcnb_package::cross_compile::{cross_compile_assistance, CrossCompileAssistance};
 use libcnb_package::dependency_graph::{create_dependency_graph, get_dependencies};
+use libcnb_package::output::create_packaged_buildpack_dir_resolver;
 use libcnb_package::{
-    assemble_buildpack_directory, find_buildpack_dirs, find_cargo_workspace_root_dir,
-    get_buildpack_package_dir, CargoProfile,
+    assemble_buildpack_directory, find_buildpack_dirs, find_cargo_workspace_root_dir, CargoProfile,
 };
-use std::collections::HashMap;
+use std::ffi::OsString;
 use std::path::{Path, PathBuf};
 
 type Result<T> = std::result::Result<T, Error>;
 
+#[allow(clippy::too_many_lines)]
 pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
+    let target_triple = args.target.clone();
+
+    let cargo_profile = if args.release {
+        CargoProfile::Release
+    } else {
+        CargoProfile::Dev
+    };
+
     eprintln!("🔍 Locating buildpacks...");
 
     let current_dir = std::env::current_dir().map_err(Error::GetCurrentDir)?;
@@ -43,19 +52,6 @@ pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
 
     let buildpack_packages_graph = create_dependency_graph(buildpack_packages)?;
 
-    let target_directories_index = buildpack_packages_graph
-        .node_weights()
-        .map(|buildpack_package| {
-            let id = buildpack_package.buildpack_id();
-            let target_dir = if contains_buildpack_binaries(&buildpack_package.path) {
-                buildpack_package.path.clone()
-            } else {
-                get_buildpack_package_dir(id, &package_dir, args.release, &args.target)
-            };
-            (id, target_dir)
-        })
-        .collect::<HashMap<_, _>>();
-
     let buildpack_packages_requested = buildpack_packages_graph
         .node_weights()
         .filter(|buildpack_package| {
@@ -75,13 +71,15 @@ pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
 
     let build_order = get_dependencies(&buildpack_packages_graph, &buildpack_packages_requested)?;
 
+    let packaged_buildpack_dir_resolver =
+        create_packaged_buildpack_dir_resolver(&package_dir, cargo_profile, &target_triple);
+
     let lookup_target_dir = |buildpack_package: &BuildpackPackage| {
-        target_directories_index
-            .get(&buildpack_package.buildpack_id())
-            .ok_or(Error::TargetDirectoryLookup {
-                buildpack_id: buildpack_package.buildpack_id().clone(),
-            })
-            .map(std::clone::Clone::clone)
+        if contains_buildpack_binaries(&buildpack_package.path) {
+            buildpack_package.path.clone()
+        } else {
+            packaged_buildpack_dir_resolver(buildpack_package.buildpack_id())
+        }
     };
 
     let mut current_count = 1;
@@ -91,17 +89,27 @@ pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
             "📦 [{current_count}/{total_count}] Building {}",
             buildpack_package.buildpack_id()
         );
-        let target_dir = lookup_target_dir(buildpack_package)?;
+        let target_dir = lookup_target_dir(buildpack_package);
         match buildpack_package.buildpack_data.buildpack_descriptor {
             BuildpackDescriptor::Single(_) => {
                 if contains_buildpack_binaries(&buildpack_package.path) {
                     eprintln!("Not a libcnb.rs buildpack, nothing to compile...");
                 } else {
-                    package_single_buildpack(buildpack_package, &target_dir, args)?;
+                    package_single_buildpack(
+                        buildpack_package,
+                        &target_dir,
+                        cargo_profile,
+                        &target_triple,
+                        args.no_cross_compile_assistance,
+                    )?;
                 }
             }
             BuildpackDescriptor::Meta(_) => {
-                package_meta_buildpack(buildpack_package, &target_dir, &target_directories_index)?;
+                package_meta_buildpack(
+                    buildpack_package,
+                    &target_dir,
+                    &packaged_buildpack_dir_resolver,
+                )?;
             }
         }
         current_count += 1;
@@ -111,14 +119,14 @@ pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
         build_order
             .into_iter()
             .map(lookup_target_dir)
-            .collect::<Result<Vec<_>>>()?,
+            .collect::<Vec<_>>(),
     );
 
     print_requested_buildpack_output_dirs(
         buildpack_packages_requested
             .into_iter()
             .map(lookup_target_dir)
-            .collect::<Result<Vec<_>>>()?,
+            .collect::<Vec<_>>(),
     );
 
     Ok(())
@@ -127,16 +135,10 @@ pub(crate) fn execute(args: &PackageArgs) -> Result<()> {
 fn package_single_buildpack(
     buildpack_package: &BuildpackPackage,
     target_dir: &Path,
-    args: &PackageArgs,
+    cargo_profile: CargoProfile,
+    target_triple: &str,
+    no_cross_compile_assistance: bool,
 ) -> Result<()> {
-    let cargo_profile = if args.release {
-        CargoProfile::Release
-    } else {
-        CargoProfile::Dev
-    };
-
-    let target_triple = &args.target;
-
     let cargo_metadata = MetadataCommand::new()
         .manifest_path(&buildpack_package.path.join("Cargo.toml"))
         .exec()
@@ -145,25 +147,7 @@ fn package_single_buildpack(
             source: e,
         })?;
 
-    let cargo_build_env = if args.no_cross_compile_assistance {
-        vec![]
-    } else {
-        eprintln!("Determining automatic cross-compile settings...");
-        match cross_compile_assistance(target_triple) {
-            CrossCompileAssistance::Configuration { cargo_env } => cargo_env,
-
-            CrossCompileAssistance::NoAssistance => {
-                eprintln!("Could not determine automatic cross-compile settings for target triple {target_triple}.");
-                eprintln!("This is not an error, but without proper cross-compile settings in your Cargo manifest and locally installed toolchains, compilation might fail.");
-                eprintln!("To disable this warning, pass --no-cross-compile-assistance.");
-                vec![]
-            }
-
-            CrossCompileAssistance::HelpText(help_text) => {
-                Err(Error::CrossCompilationHelp { message: help_text })?
-            }
-        }
-    };
+    let cargo_build_env = get_cargo_build_env(target_triple, no_cross_compile_assistance)?;
 
     eprintln!("Building binaries ({target_triple})...");
 
@@ -198,7 +182,7 @@ fn package_single_buildpack(
 fn package_meta_buildpack(
     buildpack_package: &BuildpackPackage,
     target_dir: &Path,
-    target_dirs_by_buildpack_id: &HashMap<&BuildpackId, PathBuf>,
+    packaged_buildpack_dir_resolver: &impl Fn(&BuildpackId) -> PathBuf,
 ) -> Result<()> {
     eprintln!("Writing buildpack directory...");
 
@@ -219,7 +203,7 @@ fn package_meta_buildpack(
         .map(|buildpackage_data| &buildpackage_data.buildpackage_descriptor)
         .ok_or(Error::MissingBuildpackageData)
         .and_then(|buildpackage| {
-            rewrite_buildpackage_local_dependencies(buildpackage, target_dirs_by_buildpack_id)
+            rewrite_buildpackage_local_dependencies(buildpackage, packaged_buildpack_dir_resolver)
                 .map_err(std::convert::Into::into)
         })
         .and_then(|buildpackage| {
@@ -319,6 +303,31 @@ fn contains_buildpack_binaries(dir: &Path) -> bool {
         .all(|path| path.is_file())
 }
 
+fn get_cargo_build_env(
+    target_triple: &str,
+    no_cross_compile_assistance: bool,
+) -> Result<Vec<(OsString, OsString)>> {
+    if no_cross_compile_assistance {
+        Ok(vec![])
+    } else {
+        eprintln!("Determining automatic cross-compile settings...");
+        match cross_compile_assistance(target_triple) {
+            CrossCompileAssistance::Configuration { cargo_env } => Ok(cargo_env),
+
+            CrossCompileAssistance::NoAssistance => {
+                eprintln!("Could not determine automatic cross-compile settings for target triple {target_triple}.");
+                eprintln!("This is not an error, but without proper cross-compile settings in your Cargo manifest and locally installed toolchains, compilation might fail.");
+                eprintln!("To disable this warning, pass --no-cross-compile-assistance.");
+                Ok(vec![])
+            }
+
+            CrossCompileAssistance::HelpText(help_text) => {
+                Err(Error::CrossCompilationHelp(help_text))?
+            }
+        }
+    }
+}
+
 fn get_default_package_dir(workspace_root_path: &Path) -> Result<PathBuf> {
     MetadataCommand::new()
         .manifest_path(&workspace_root_path.join("Cargo.toml"))

libcnb-cargo/src/package/error.rs

@@ -28,11 +28,8 @@ pub(crate) enum Error {
     #[error("Could not create package directory: {0}\nError: {1}")]
     CreatePackageDirectory(PathBuf, std::io::Error),
 
-    #[error("Could not determine a target directory for buildpack with id `{buildpack_id}`")]
-    TargetDirectoryLookup { buildpack_id: BuildpackId },
-
-    #[error("{message}")]
-    CrossCompilationHelp { message: String },
+    #[error("{0}")]
+    CrossCompilationHelp(String),
 
     #[error("No environment variable named `CARGO` is set")]
     GetCargoBin(#[from] std::env::VarError),
@@ -79,9 +76,6 @@ pub(crate) enum Error {
     #[error("Failed to locate buildpack with id `{0}`")]
     BuildpackPackagesLookup(BuildpackId),
 
-    #[error("Failed to lookup target directory for dependency with id `{0}`")]
-    RewriteLocalDependencyTargetDirectoryLookup(BuildpackId),
-
     #[error("Could not convert path into buildpackage file uri: {0}")]
     InvalidPathDependency(PathBuf),
 
@@ -201,9 +195,6 @@ impl From<CreateDependencyGraphError<BuildpackId, BuildpackIdError>> for Error {
 impl From<RewriteBuildpackageLocalDependenciesError> for Error {
     fn from(value: RewriteBuildpackageLocalDependenciesError) -> Self {
         match value {
-            RewriteBuildpackageLocalDependenciesError::TargetDirectoryLookup(id) => {
-                Error::RewriteLocalDependencyTargetDirectoryLookup(id)
-            }
             RewriteBuildpackageLocalDependenciesError::InvalidDependency(path) => {
                 Error::InvalidPathDependency(path)
             }

libcnb-cargo/tests/integration_test.rs

@@ -5,7 +5,8 @@
 use libcnb_data::buildpack::BuildpackId;
 use libcnb_data::buildpack_id;
 use libcnb_data::buildpackage::BuildpackageDependency;
-use libcnb_package::{read_buildpack_data, read_buildpackage_data};
+use libcnb_package::output::create_packaged_buildpack_dir_resolver;
+use libcnb_package::{read_buildpack_data, read_buildpackage_data, CargoProfile};
 use std::io::ErrorKind;
 use std::path::{Path, PathBuf};
 use std::process::Command;
@@ -26,7 +27,7 @@ fn package_buildpack_in_single_buildpack_project() {
 
     let packaged_buildpack_dir = create_packaged_buildpack_dir_resolver(
         &fixture_dir.path().join(DEFAULT_PACKAGE_DIR_NAME),
-        true,
+        CargoProfile::Release,
         X86_64_UNKNOWN_LINUX_MUSL,
     )(&buildpack_id);
 
@@ -51,7 +52,7 @@ fn package_single_meta_buildpack_in_monorepo_buildpack_project() {
 
     let packaged_buildpack_dir_resolver = create_packaged_buildpack_dir_resolver(
         &fixture_dir.path().join(DEFAULT_PACKAGE_DIR_NAME),
-        true,
+        CargoProfile::Release,
         X86_64_UNKNOWN_LINUX_MUSL,
     );
 
@@ -111,7 +112,7 @@ fn package_single_buildpack_in_monorepo_buildpack_project() {
 
     let packaged_buildpack_dir = create_packaged_buildpack_dir_resolver(
         &fixture_dir.path().join(DEFAULT_PACKAGE_DIR_NAME),
-        true,
+        CargoProfile::Release,
         X86_64_UNKNOWN_LINUX_MUSL,
     )(&buildpack_id);
 
@@ -141,7 +142,7 @@ fn package_all_buildpacks_in_monorepo_buildpack_project() {
 
     let packaged_buildpack_dir_resolver = create_packaged_buildpack_dir_resolver(
         &fixture_dir.path().join(DEFAULT_PACKAGE_DIR_NAME),
-        true,
+        CargoProfile::Release,
         X86_64_UNKNOWN_LINUX_MUSL,
     );
 
@@ -274,22 +275,6 @@ fn validate_packaged_meta_buildpack(
     );
 }
 
-fn create_packaged_buildpack_dir_resolver(
-    package_dir: &Path,
-    release: bool,
-    target_triple: &str,
-) -> impl Fn(&BuildpackId) -> PathBuf {
-    let package_dir = PathBuf::from(package_dir);
-    let target_triple = target_triple.to_string();
-
-    move |buildpack_id| {
-        package_dir
-            .join(&target_triple)
-            .join(if release { "release" } else { "debug" })
-            .join(buildpack_id.as_str().replace('/', "_"))
-    }
-}
-
 fn copy_fixture_to_temp_dir(name: &str) -> Result<TempDir, std::io::Error> {
     let fixture_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
         .join("fixtures")