Skip default process registration when Procfile is present (#985)

* Skip default process registration when Procfile is present

This change treats the presence of a `Procfile` as the "source of truth" for how processes should be registered and will skip the default process registration that was previously performed for `npm`, `yarn`, and `pnpm`.

Fixes #908

Related to heroku/buildpacks-go#319

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update CHANGELOG.md

buildpacks/nodejs-npm-install/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Default processes will no longer be registered if a Procfile is present. ([#985](https://github.com/heroku/buildpacks-nodejs/pull/985))
+
 ## [3.3.5] - 2024-12-11
 
 - No changes.

buildpacks/nodejs-npm-install/src/main.rs

@@ -100,7 +100,7 @@ impl Buildpack for NpmInstallBuildpack {
         let logger = section.end_section();
 
         let section = logger.section("Configuring default processes");
-        let build_result = configure_default_processes(&package_json, section.as_ref());
+        let build_result = configure_default_processes(&context, &package_json, section.as_ref());
         let logger = section.end_section();
 
         configure_npm_runtime_env(&context)?;
@@ -198,10 +198,14 @@ fn run_build_scripts(
 }
 
 fn configure_default_processes(
+    context: &BuildContext<NpmInstallBuildpack>,
     package_json: &PackageJson,
     _section_logger: &dyn SectionLogger,
 ) -> Result<BuildResult, libcnb::Error<NpmInstallBuildpackError>> {
-    if package_json.has_start_script() {
+    if context.app_dir.join("Procfile").exists() {
+        log_step("Skipping default web process (Procfile detected)");
+        BuildResultBuilder::new().build()
+    } else if package_json.has_start_script() {
         log_step(format!(
             "Adding default web process for {}",
             fmt::value("npm start")

buildpacks/nodejs-npm-install/tests/integration_test.rs

@@ -269,6 +269,25 @@ fn test_skip_build_scripts_from_buildplan() {
     );
 }
 
+#[test]
+#[ignore]
+fn test_default_web_process_registration_is_skipped_if_procfile_exists() {
+    nodejs_integration_test_with_config(
+        "./fixtures/npm-project",
+        |config| {
+            config.app_dir_preprocessor(|app_dir| {
+                std::fs::File::create(app_dir.join("Procfile")).unwrap();
+            });
+        },
+        |ctx| {
+            assert_contains!(
+                ctx.pack_stdout,
+                "Skipping default web process (Procfile detected)"
+            );
+        },
+    );
+}
+
 fn add_lockfile_entry(app_dir: &Path, package_name: &str, lockfile_entry: serde_json::Value) {
     update_json_file(&app_dir.join("package-lock.json"), |json| {
         let dependencies = json["dependencies"].as_object_mut().unwrap();

buildpacks/nodejs-pnpm-install/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Default processes will no longer be registered if a Procfile is present. ([#985](https://github.com/heroku/buildpacks-nodejs/pull/985))
+
 ## [3.3.5] - 2024-12-11
 
 - No changes.

buildpacks/nodejs-pnpm-install/src/main.rs

@@ -97,7 +97,11 @@ impl Buildpack for PnpmInstallBuildpack {
         }
 
         let result_builder = BuildResultBuilder::new().store(Store { metadata });
-        if pkg_json.has_start_script() {
+
+        if context.app_dir.join("Procfile").exists() {
+            log_info("Skipping default web process (Procfile detected)");
+            result_builder.build()
+        } else if pkg_json.has_start_script() {
             result_builder
                 .launch(
                     LaunchBuilder::new()

buildpacks/nodejs-pnpm-install/tests/integration_test.rs

@@ -6,7 +6,7 @@ use libcnb::data::buildpack_id;
 use libcnb_test::{assert_contains, assert_empty, BuildpackReference};
 use test_support::{
     add_build_script, assert_web_response, custom_buildpack, integration_test_with_config,
-    nodejs_integration_test,
+    nodejs_integration_test, nodejs_integration_test_with_config,
 };
 
 #[test]
@@ -215,3 +215,22 @@ fn test_skip_build_scripts_from_buildplan() {
         ],
     );
 }
+
+#[test]
+#[ignore = "integration test"]
+fn test_default_web_process_registration_is_skipped_if_procfile_exists() {
+    nodejs_integration_test_with_config(
+        "./fixtures/pnpm-9",
+        |config| {
+            config.app_dir_preprocessor(|app_dir| {
+                std::fs::File::create(app_dir.join("Procfile")).unwrap();
+            });
+        },
+        |ctx| {
+            assert_contains!(
+                ctx.pack_stdout,
+                "Skipping default web process (Procfile detected)"
+            );
+        },
+    );
+}

buildpacks/nodejs-yarn/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Default processes will no longer be registered if a Procfile is present. ([#985](https://github.com/heroku/buildpacks-nodejs/pull/985))
+
 ## [3.3.5] - 2024-12-11
 
 - No changes.

buildpacks/nodejs-yarn/src/main.rs

@@ -154,7 +154,10 @@ impl Buildpack for YarnBuildpack {
             }
         }
 
-        if pkg_json.has_start_script() {
+        if context.app_dir.join("Procfile").exists() {
+            log_info("Skipping default web process (Procfile detected)");
+            BuildResultBuilder::new().build()
+        } else if pkg_json.has_start_script() {
             BuildResultBuilder::new()
                 .launch(
                     LaunchBuilder::new()

buildpacks/nodejs-yarn/tests/integration_test.rs

@@ -6,7 +6,7 @@ use libcnb::data::buildpack_id;
 use libcnb_test::{assert_contains, assert_not_contains, BuildpackReference};
 use test_support::{
     add_build_script, assert_web_response, custom_buildpack, integration_test_with_config,
-    nodejs_integration_test,
+    nodejs_integration_test, nodejs_integration_test_with_config,
 };
 
 #[test]
@@ -214,3 +214,22 @@ fn test_skip_build_scripts_from_buildplan() {
         ],
     );
 }
+
+#[test]
+#[ignore = "integration test"]
+fn test_default_web_process_registration_is_skipped_if_procfile_exists() {
+    nodejs_integration_test_with_config(
+        "./fixtures/yarn-project",
+        |config| {
+            config.app_dir_preprocessor(|app_dir| {
+                std::fs::File::create(app_dir.join("Procfile")).unwrap();
+            });
+        },
+        |ctx| {
+            assert_contains!(
+                ctx.pack_stdout,
+                "Skipping default web process (Procfile detected)"
+            );
+        },
+    );
+}