Support local buildpacks and meta-buildpacks in libcnb-test

.gitignore

@@ -5,3 +5,4 @@
 Cargo.lock
 **/fixtures/*/target/
 **/fixtures/*/packaged/
+**/test-fixtures/buildpacks/*/target/

CHANGELOG.md

@@ -14,13 +14,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `libcnb-data`:
   - `ExecDProgramOutputKey`, `ProcessType`, `LayerName`, `BuildpackId` and `StackId` now implement `Ord` and `PartialOrd`. ([#658](https://github.com/heroku/libcnb.rs/pull/658))
   - Add `generic::GenericMetadata` as a generic metadata type. Also makes it the default for `BuildpackDescriptor`, `SingleBuildpackDescriptor`, `MetaBuildpackDescriptor` and `LayerContentMetadata`. ([#664](https://github.com/heroku/libcnb.rs/pull/664))
+- `libcnb-test`:
+  - Added the variant `WorkspaceBuildpack` to the `build_config::BuildpackReference` enum which allows any buildpack within the Rust workspace to be referenced for testing. ([#666](https://github.com/heroku/libcnb.rs/pull/666))
+  - Testing of composite buildpacks is now supported using the `WorkspaceBuildpack` variant - **Requires `pack` CLI version `>=0.30`**. ([#666](https://github.com/heroku/libcnb.rs/pull/666))
 
 ### Changed
 
 - Renamed `libcnb-data`'s `Buildpackage` to `PackageDescriptor`. This required changes in many other names across multiple libcnb.rs crates for consistency. See the PR diff for details, but renames should be straightforward and unsurprising. ([#656](https://github.com/heroku/libcnb.rs/pull/656))
 - `libcnb-cargo`:
   - No longer outputs paths for non-libcnb.rs and non-meta buildpacks. ([#657](https://github.com/heroku/libcnb.rs/pull/657))
   - Build output for humans changed slightly, output intended for machines/scripting didn't change. ([#657](https://github.com/heroku/libcnb.rs/pull/657))
+- `libcnb-test`:
+  - Renamed the variant `Crate` to `CurrentCrate` for the `build_config::BuildpackReference` enum which references the buildpack within the Rust Crate currently being tested. ([#666](https://github.com/heroku/libcnb.rs/pull/666))
 
 ## [0.14.0] - 2023-08-18
 

libcnb-test/Cargo.toml

@@ -12,9 +12,9 @@ readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
 [dependencies]
-cargo_metadata = "0.17.0"
 fastrand = "2.0.0"
 fs_extra = "1.3.0"
+libcnb-common.workspace = true
 libcnb-data.workspace = true
 libcnb-package.workspace = true
 tempfile = "3.7.1"

libcnb-test/README.md

@@ -191,13 +191,15 @@ fn dynamic_fixture() {
 Building with multiple buildpacks, using [`BuildConfig::buildpacks`]:
 
 ```rust,no_run
+use libcnb_data::buildpack_id;
 use libcnb_test::{BuildConfig, BuildpackReference, TestRunner};
 
 // #[test]
 fn additional_buildpacks() {
     TestRunner::default().build(
         BuildConfig::new("heroku/builder:22", "test-fixtures/app").buildpacks(vec![
-            BuildpackReference::Crate,
+            BuildpackReference::CurrentCrate,
+            BuildpackReference::WorkspaceBuildpack(buildpack_id!("my-project/buildpack")),
             BuildpackReference::Other(String::from("heroku/another-buildpack")),
         ]),
         |context| {

libcnb-test/src/build.rs

@@ -1,62 +1,138 @@
-use cargo_metadata::MetadataCommand;
-use libcnb_package::build::{build_buildpack_binaries, BuildBinariesError};
+use libcnb_common::toml_file::{read_toml_file, TomlFileError};
+use libcnb_data::buildpack::{BuildpackDescriptor, BuildpackId};
+use libcnb_package::buildpack_dependency_graph::{
+    build_libcnb_buildpacks_dependency_graph, BuildBuildpackDependencyGraphError,
+};
 use libcnb_package::cross_compile::{cross_compile_assistance, CrossCompileAssistance};
-use libcnb_package::{assemble_buildpack_directory, CargoProfile};
+use libcnb_package::dependency_graph::{get_dependencies, GetDependenciesError};
+use libcnb_package::output::create_packaged_buildpack_dir_resolver;
+use libcnb_package::package::PackageBuildpackError;
+use libcnb_package::{find_cargo_workspace_root_dir, CargoProfile, FindCargoWorkspaceRootError};
+use std::collections::BTreeMap;
+use std::fs;
 use std::path::PathBuf;
 use tempfile::{tempdir, TempDir};
 
 /// Packages the current crate as a buildpack into a temporary directory.
 pub(crate) fn package_crate_buildpack(
     cargo_profile: CargoProfile,
     target_triple: impl AsRef<str>,
-) -> Result<TempDir, PackageCrateBuildpackError> {
+) -> Result<PackagedBuildpackDir, PackageTestBuildpackError> {
     let cargo_manifest_dir = std::env::var("CARGO_MANIFEST_DIR")
         .map(PathBuf::from)
-        .map_err(PackageCrateBuildpackError::CannotDetermineCrateDirectory)?;
+        .map_err(PackageTestBuildpackError::CannotDetermineCrateDirectory)?;
 
-    let cargo_metadata = MetadataCommand::new()
-        .manifest_path(&cargo_manifest_dir.join("Cargo.toml"))
-        .exec()
-        .map_err(PackageCrateBuildpackError::CargoMetadataError)?;
+    let buildpack_toml = cargo_manifest_dir.join("buildpack.toml");
 
-    let cargo_env = match cross_compile_assistance(target_triple.as_ref()) {
+    assert!(
+        buildpack_toml.exists(),
+        "Could not package directory as buildpack! No `buildpack.toml` file exists at {}",
+        cargo_manifest_dir.display()
+    );
+
+    let buildpack_descriptor: BuildpackDescriptor =
+        read_toml_file(buildpack_toml).map_err(PackageTestBuildpackError::CannotReadBuildpack)?;
+
+    package_buildpack(
+        &buildpack_descriptor.buildpack().id,
+        cargo_profile,
+        target_triple,
+    )
+}
+
+pub(crate) fn package_buildpack(
+    buildpack_id: &BuildpackId,
+    cargo_profile: CargoProfile,
+    target_triple: impl AsRef<str>,
+) -> Result<PackagedBuildpackDir, PackageTestBuildpackError> {
+    let cargo_manifest_dir = std::env::var("CARGO_MANIFEST_DIR")
+        .map(PathBuf::from)
+        .map_err(PackageTestBuildpackError::CannotDetermineCrateDirectory)?;
+
+    let cargo_build_env = match cross_compile_assistance(target_triple.as_ref()) {
         CrossCompileAssistance::HelpText(help_text) => {
-            return Err(PackageCrateBuildpackError::CrossCompileConfigurationError(
+            return Err(PackageTestBuildpackError::CrossCompileConfigurationError(
                 help_text,
             ));
         }
         CrossCompileAssistance::NoAssistance => Vec::new(),
         CrossCompileAssistance::Configuration { cargo_env } => cargo_env,
     };
 
-    let buildpack_dir =
-        tempdir().map_err(PackageCrateBuildpackError::CannotCreateBuildpackTempDirectory)?;
+    let workspace_root_path = find_cargo_workspace_root_dir(&cargo_manifest_dir)
+        .map_err(PackageTestBuildpackError::FindCargoWorkspace)?;
 
-    let buildpack_binaries = build_buildpack_binaries(
-        &cargo_manifest_dir,
-        &cargo_metadata,
+    let package_dir =
+        tempdir().map_err(PackageTestBuildpackError::CannotCreateBuildpackTempDirectory)?;
+
+    let buildpack_dir_resolver = create_packaged_buildpack_dir_resolver(
+        package_dir.as_ref(),
         cargo_profile,
-        &cargo_env,
         target_triple.as_ref(),
-    )
-    .map_err(PackageCrateBuildpackError::BuildBinariesError)?;
+    );
+
+    // TODO: this could accidentally detect a packaged meta-buildpack twice. how should we ignore directories
+    //       containing packaged buildpacks that might get detected now that the user controls --package-dir?
+    //       - support .gitignore or some other persistent configuration?
+    //       - during packaging should we create some type of file that indicates the output is a packaged buildpack?
+    let buildpack_dependency_graph =
+        build_libcnb_buildpacks_dependency_graph(&workspace_root_path, &[])
+            .map_err(PackageTestBuildpackError::CreateBuildpackDependencyGraph)?;
 
-    assemble_buildpack_directory(
-        buildpack_dir.path(),
-        cargo_manifest_dir.join("buildpack.toml"),
-        &buildpack_binaries,
+    let root_node = buildpack_dependency_graph
+        .node_weights()
+        .find(|node| node.buildpack_id == buildpack_id.clone());
+
+    assert!(
+        root_node.is_some(),
+        "Could not package directory as buildpack! No buildpack with id `{buildpack_id}` exists in the workspace at {}",
+        workspace_root_path.display()
+    );
+
+    let build_order = get_dependencies(
+        &buildpack_dependency_graph,
+        &[root_node.expect("The root node should exist")],
     )
-    .map_err(PackageCrateBuildpackError::CannotAssembleBuildpackDirectory)?;
+    .map_err(PackageTestBuildpackError::GetDependencies)?;
+
+    let mut packaged_buildpack_dirs = BTreeMap::new();
+    for node in &build_order {
+        let buildpack_destination_dir = buildpack_dir_resolver(&node.buildpack_id);
+
+        fs::create_dir_all(&buildpack_destination_dir).unwrap();
+
+        libcnb_package::package::package_buildpack(
+            &node.path,
+            cargo_profile,
+            target_triple.as_ref(),
+            &cargo_build_env,
+            &buildpack_destination_dir,
+            &packaged_buildpack_dirs,
+        )
+        .map_err(PackageTestBuildpackError::PackageBuildpack)?;
+
+        packaged_buildpack_dirs.insert(node.buildpack_id.clone(), buildpack_destination_dir);
+    }
+
+    Ok(PackagedBuildpackDir {
+        _root: package_dir,
+        path: buildpack_dir_resolver(buildpack_id),
+    })
+}
 
-    Ok(buildpack_dir)
+pub(crate) struct PackagedBuildpackDir {
+    _root: TempDir,
+    pub(crate) path: PathBuf,
 }
 
 #[derive(Debug)]
-pub(crate) enum PackageCrateBuildpackError {
-    BuildBinariesError(BuildBinariesError),
-    CannotAssembleBuildpackDirectory(std::io::Error),
+pub(crate) enum PackageTestBuildpackError {
     CannotCreateBuildpackTempDirectory(std::io::Error),
     CannotDetermineCrateDirectory(std::env::VarError),
-    CargoMetadataError(cargo_metadata::Error),
+    CannotReadBuildpack(TomlFileError),
+    CreateBuildpackDependencyGraph(BuildBuildpackDependencyGraphError),
     CrossCompileConfigurationError(String),
+    FindCargoWorkspace(FindCargoWorkspaceRootError),
+    GetDependencies(GetDependenciesError<BuildpackId>),
+    PackageBuildpack(PackageBuildpackError),
 }

libcnb-test/src/build_config.rs

@@ -1,3 +1,4 @@
+use libcnb_data::buildpack::BuildpackId;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
@@ -41,7 +42,7 @@ impl BuildConfig {
             cargo_profile: CargoProfile::Dev,
             target_triple: String::from("x86_64-unknown-linux-musl"),
             builder_name: builder_name.into(),
-            buildpacks: vec![BuildpackReference::Crate],
+            buildpacks: vec![BuildpackReference::CurrentCrate],
             env: HashMap::new(),
             app_dir_preprocessor: None,
             expected_pack_result: PackResult::Success,
@@ -50,7 +51,7 @@ impl BuildConfig {
 
     /// Sets the buildpacks (and their ordering) to use when building the app.
     ///
-    /// Defaults to [`BuildpackReference::Crate`].
+    /// Defaults to [`BuildpackReference::CurrentCrate`].
     ///
     /// # Example
     /// ```no_run
@@ -59,7 +60,7 @@ impl BuildConfig {
     /// TestRunner::default().build(
     ///     BuildConfig::new("heroku/builder:22", "test-fixtures/app").buildpacks(vec![
     ///         BuildpackReference::Other(String::from("heroku/another-buildpack")),
-    ///         BuildpackReference::Crate,
+    ///         BuildpackReference::CurrentCrate,
     ///     ]),
     ///     |context| {
     ///         // ...
@@ -250,7 +251,9 @@ impl BuildConfig {
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub enum BuildpackReference {
     /// References the buildpack in the Rust Crate currently being tested.
-    Crate,
+    CurrentCrate,
+    /// References a libcnb.rs buildpack within the Rust Workspace that needs to be packaged into a buildpack
+    WorkspaceBuildpack(BuildpackId),
     /// References another buildpack by id, local directory or tarball.
     Other(String),
 }

libcnb-test/src/test_runner.rs

@@ -88,14 +88,7 @@ impl TestRunner {
             }
         };
 
-        let temp_crate_buildpack_dir =
-            config
-                .buildpacks
-                .contains(&BuildpackReference::Crate)
-                .then(|| {
-                    build::package_crate_buildpack(config.cargo_profile, &config.target_triple)
-                        .expect("Could not package current crate as buildpack")
-                });
+        let mut buildpack_dirs = vec![];
 
         let mut pack_command = PackBuildCommand::new(&config.builder_name, &app_dir, &image_name);
 
@@ -105,11 +98,23 @@ impl TestRunner {
 
         for buildpack in &config.buildpacks {
             match buildpack {
-                BuildpackReference::Crate => {
-                    pack_command.buildpack(temp_crate_buildpack_dir.as_ref()
-                        .expect("Test references crate buildpack, but crate wasn't packaged as a buildpack. This is an internal libcnb-test error, please report any occurrences."))
+                BuildpackReference::CurrentCrate => {
+                    let crate_buildpack_dir = build::package_crate_buildpack(config.cargo_profile, &config.target_triple)
+                        .expect("Test references crate buildpack, but crate wasn't packaged as a buildpack. This is an internal libcnb-test error, please report any occurrences");
+                    pack_command.buildpack(crate_buildpack_dir.path.clone());
+                    buildpack_dirs.push(crate_buildpack_dir);
+                }
+
+                BuildpackReference::WorkspaceBuildpack(builpack_id) => {
+                    let buildpack_dir = build::package_buildpack(builpack_id, config.cargo_profile, &config.target_triple)
+                        .unwrap_or_else(|_| panic!("Test references buildpack `{builpack_id}`, but this directory wasn't packaged as a buildpack. This is an internal libcnb-test error, please report any occurrences"));
+                    pack_command.buildpack(buildpack_dir.path.clone());
+                    buildpack_dirs.push(buildpack_dir);
+                }
+
+                BuildpackReference::Other(id) => {
+                    pack_command.buildpack(id.clone());
                 }
-                BuildpackReference::Other(id) => pack_command.buildpack(id.clone()),
             };
         }
 

libcnb-test/test-fixtures/buildpacks/libcnb-test-a/Cargo.toml

@@ -0,0 +1,5 @@
+[package]
+name = "one"
+version = "0.0.0"
+
+[workspace]

libcnb-test/test-fixtures/buildpacks/libcnb-test-a/buildpack.toml

@@ -0,0 +1,8 @@
+api = "0.8"
+
+[buildpack]
+id = "libcnb-test/a"
+version = "0.0.0"
+
+[[stacks]]
+id = "*"

libcnb-test/test-fixtures/buildpacks/libcnb-test-a/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Buildpack A");
+}

libcnb-test/test-fixtures/buildpacks/libcnb-test-b/Cargo.toml

@@ -0,0 +1,5 @@
+[package]
+name = "two"
+version = "0.0.0"
+
+[workspace]

libcnb-test/test-fixtures/buildpacks/libcnb-test-b/buildpack.toml

@@ -0,0 +1,8 @@
+api = "0.8"
+
+[buildpack]
+id = "libcnb-test/b"
+version = "0.0.0"
+
+[[stacks]]
+id = "*"

libcnb-test/test-fixtures/buildpacks/libcnb-test-b/src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Buildpack B");
+}

libcnb-test/test-fixtures/buildpacks/libcnb-test-meta/buildpack.toml

@@ -0,0 +1,22 @@
+api = "0.8"
+
+[buildpack]
+id = "libcnb-test/meta"
+name = "Meta-buildpack Test"
+version = "0.0.0"
+homepage = "https://example.com"
+description = "Official test example"
+keywords = ["test"]
+
+[[buildpack.licenses]]
+type = "BSD-3-Clause"
+
+[[order]]
+
+[[order.group]]
+id = "libcnb-test/a"
+version = "0.0.0"
+
+[[order.group]]
+id = "libcnb-test/b"
+version = "0.0.0"

libcnb-test/test-fixtures/buildpacks/libcnb-test-meta/package.toml

@@ -0,0 +1,9 @@
+[buildpack]
+uri = "."
+
+[[dependencies]]
+uri = "libcnb:libcnb-test/a"
+
+[[dependencies]]
+uri = "libcnb:libcnb-test/b"
+