Add tests for runtime.txt containing invalid unicode

src/layers/pip_dependencies.rs

@@ -159,11 +159,11 @@ mod tests {
 
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply(Scope::Build, &base_env)),
-            vec![("PYTHONUSERBASE", "/layers/dependencies")]
+            [("PYTHONUSERBASE", "/layers/dependencies")]
         );
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply(Scope::Launch, &base_env)),
-            vec![("PYTHONUSERBASE", "/layers/dependencies")]
+            [("PYTHONUSERBASE", "/layers/dependencies")]
         );
     }
 }

src/layers/python.rs

@@ -477,7 +477,7 @@ mod tests {
         };
         assert_eq!(
             cache_invalidation_reasons(&cached_metadata, &new_metadata),
-            vec!["The Python version has changed from 3.11.0 to 3.11.1"]
+            ["The Python version has changed from 3.11.0 to 3.11.1"]
         );
     }
 
@@ -503,7 +503,7 @@ mod tests {
         };
         assert_eq!(
             cache_invalidation_reasons(&cached_metadata, &new_metadata),
-            vec![
+            [
                 "The stack has changed from heroku-20 to heroku-22",
                 "The Python version has changed from 3.9.0 to 3.11.1",
                 "The pip version has changed from A.B.C to A.B.C-new",
@@ -527,7 +527,7 @@ mod tests {
         // Remember to force invalidation of the cached layer if these env vars ever change.
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply_to_empty(Scope::Build)),
-            vec![
+            [
                 ("CPATH", "/layers/python/include/python3.9"),
                 ("LANG", "C.UTF-8"),
                 ("PIP_DISABLE_PIP_VERSION_CHECK", "1"),
@@ -539,7 +539,7 @@ mod tests {
         );
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply_to_empty(Scope::Launch)),
-            vec![
+            [
                 ("CPATH", "/layers/python/include/python3.9"),
                 ("LANG", "C.UTF-8"),
                 ("PIP_DISABLE_PIP_VERSION_CHECK", "1"),
@@ -573,7 +573,7 @@ mod tests {
         // Remember to force invalidation of the cached layer if these env vars ever change.
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply(Scope::Build, &base_env)),
-            vec![
+            [
                 ("CPATH", "/layers/python/include/python3.11:/base"),
                 ("LANG", "C.UTF-8"),
                 ("PIP_DISABLE_PIP_VERSION_CHECK", "1"),
@@ -585,7 +585,7 @@ mod tests {
         );
         assert_eq!(
             utils::environment_as_sorted_vector(&layer_env.apply(Scope::Launch, &base_env)),
-            vec![
+            [
                 ("CPATH", "/layers/python/include/python3.11:/base"),
                 ("LANG", "C.UTF-8"),
                 ("PIP_DISABLE_PIP_VERSION_CHECK", "1"),

src/runtime_txt.rs

@@ -218,6 +218,10 @@ mod tests {
             read_version(Path::new("tests/fixtures/empty/.gitkeep")).unwrap_err(),
             RuntimeTxtError::Read(_)
         ));
+        assert!(matches!(
+            read_version(Path::new("tests/fixtures/runtime_txt_invalid_unicode")).unwrap_err(),
+            RuntimeTxtError::Read(_)
+        ));
     }
 
     #[test]

tests/fixtures/runtime_txt_invalid_unicode/runtime.txt

@@ -0,0 +1 @@
+��

tests/pip_test.rs

@@ -106,7 +106,7 @@ fn pip_cache_invalidation_and_metadata_compatibility() {
     let config = BuildConfig::new(builder(), "tests/fixtures/pip_basic");
 
     TestRunner::default().build(
-        config.clone().buildpacks(vec![BuildpackReference::Other(
+        config.clone().buildpacks([BuildpackReference::Other(
             "docker://docker.io/heroku/buildpack-python:0.1.0".to_string(),
         )]),
         |context| {

tests/python_version_test.rs

@@ -144,6 +144,26 @@ fn builds_with_python_version(fixture_path: &str, python_version: &str) {
     });
 }
 
+#[test]
+#[ignore = "integration test"]
+fn runtime_txt_io_error() {
+    TestRunner::default().build(
+        BuildConfig::new(builder(), "tests/fixtures/runtime_txt_invalid_unicode")
+            .expected_pack_result(PackResult::Failure),
+        |context| {
+            assert_contains!(
+                context.pack_stderr,
+                &formatdoc! {"
+                    [Error: Unable to read runtime.txt]
+                    An unexpected error occurred whilst reading the (optional) runtime.txt file.
+
+                    Details: I/O Error: stream did not contain valid UTF-8
+                "}
+            );
+        },
+    );
+}
+
 #[test]
 #[ignore = "integration test"]
 fn runtime_txt_invalid_version() {