From 0d4556b7974e50306d3f089415202f17add2f09b Mon Sep 17 00:00:00 2001
From: Colin Casey <casey.colin@gmail.com>
Date: Thu, 9 Jan 2025 16:03:33 -0400
Subject: [PATCH] Fix warning for checked in `node_modules` dir

One of the features of the `commons` logger that was removed in https://github.com/heroku/buildpacks-nodejs/pull/993 was the ability to collect log messages that would be emitted at a later point. This feature is not available in `bullet_stream` so when I moved the logging message that notifies the user they've checked in their `node_modules` directory to the end of the build phase, I mistakenly moved the timing of that check to run at the end of the build phase as well.

This check needs to run at the beginning of the build phase and the warning needs to be emitted at the end. This PR contains changes to do this + adds an integration test to verify this case.
---
 buildpacks/nodejs-npm-install/CHANGELOG.md    |  4 ++++
 buildpacks/nodejs-npm-install/src/main.rs     | 13 ++++++-----
 .../tests/integration_test.rs                 | 23 +++++++++++++++++++
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/buildpacks/nodejs-npm-install/CHANGELOG.md b/buildpacks/nodejs-npm-install/CHANGELOG.md
index 38947c7e..c93566cc 100644
--- a/buildpacks/nodejs-npm-install/CHANGELOG.md
+++ b/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]
 
+### Fixed
+
+- Warning for checked in `node_modules` di
+
 ## [3.4.2] - 2025-01-08
 
 - No changes.
diff --git a/buildpacks/nodejs-npm-install/src/main.rs b/buildpacks/nodejs-npm-install/src/main.rs
index 1ff9476d..320e338c 100644
--- a/buildpacks/nodejs-npm-install/src/main.rs
+++ b/buildpacks/nodejs-npm-install/src/main.rs
@@ -78,6 +78,8 @@ impl Buildpack for NpmInstallBuildpack {
         let node_build_scripts_metadata = read_node_build_scripts_metadata(&context.buildpack_plan)
             .map_err(NpmInstallBuildpackError::NodeBuildScriptsMetadata)?;
 
+        let prebuild_modules_warning = application::warn_prebuilt_modules(app_dir);
+
         application::check_for_singular_lockfile(app_dir)
             .map_err(NpmInstallBuildpackError::Application)?;
 
@@ -98,12 +100,11 @@ impl Buildpack for NpmInstallBuildpack {
 
         configure_npm_runtime_env(&context)?;
 
-        let logger =
-            if let Some(prebuilt_modules_warning) = application::warn_prebuilt_modules(app_dir) {
-                logger.warning(prebuilt_modules_warning)
-            } else {
-                logger
-            };
+        let logger = if let Some(warning_message) = prebuild_modules_warning {
+            logger.warning(warning_message)
+        } else {
+            logger
+        };
 
         logger.done();
         build_result
diff --git a/buildpacks/nodejs-npm-install/tests/integration_test.rs b/buildpacks/nodejs-npm-install/tests/integration_test.rs
index 05147d62..2733b1f6 100644
--- a/buildpacks/nodejs-npm-install/tests/integration_test.rs
+++ b/buildpacks/nodejs-npm-install/tests/integration_test.rs
@@ -288,6 +288,29 @@ fn test_default_web_process_registration_is_skipped_if_procfile_exists() {
     );
 }
 
+#[test]
+#[ignore]
+fn npm_modules_checked_in_warning() {
+    nodejs_integration_test("./fixtures/npm-project", |ctx| {
+        assert_not_contains!(
+            ctx.pack_stdout,
+            "Warning: `node_modules` checked into source control"
+        );
+
+        let mut config = ctx.config.clone();
+        config.app_dir_preprocessor(|app_dir| {
+            std::fs::create_dir(app_dir.join("node_modules")).unwrap();
+        });
+
+        ctx.rebuild(config, |ctx| {
+            assert_contains!(
+                ctx.pack_stdout,
+                "Warning: `node_modules` checked into source control"
+            );
+        });
+    });
+}
+
 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();