test(e2e): reproducer for #510 (fine-grained change missed through non-root-visible wrapper)

tests/e2e/regressions.rs

@@ -213,6 +213,50 @@ fn wrapped_external_repo_change_reaches_main_consumer() {
     );
 }
 
+/// Reproducer for https://github.com/Tinder/bazel-diff/issues/510: like the
+/// #197 case above, but the wrapper module (`middle`) is only declared by
+/// `facade`, under a private apparent name, so it is not visible from the root.
+#[test]
+fn hidden_wrapper_external_repo_change_reaches_main_consumer_reproducer_for_issue_510() {
+    let first = copy_workspace("hidden_wrapper_external_repo");
+    let second = copy_workspace("hidden_wrapper_external_repo");
+    fs::write(second.path().join("leaf/value.txt"), "after\n").unwrap();
+    let impacted = diff_workspaces(
+        first.path(),
+        second.path(),
+        &["--fineGrainedHashExternalRepos", "@leaf"],
+    );
+    assert!(
+        impacted
+            .iter()
+            .any(|label| label == "//:consumer" || label == "@@//:consumer"),
+        "{impacted:?}"
+    );
+    assert!(!impacted.contains("//:control"), "{impacted:?}");
+}
+
+/// Control for the issue 510 reproducer: naming every repository in the chain
+/// already propagates the change, so the fixture's edges are real and the gap
+/// is in discovering `@@middle+` from `@leaf` alone.
+#[test]
+fn hidden_wrapper_external_repo_change_propagates_with_explicit_chain() {
+    let first = copy_workspace("hidden_wrapper_external_repo");
+    let second = copy_workspace("hidden_wrapper_external_repo");
+    fs::write(second.path().join("leaf/value.txt"), "after\n").unwrap();
+    let impacted = diff_workspaces(
+        first.path(),
+        second.path(),
+        &["--fineGrainedHashExternalRepos", "@leaf,@facade,@@middle+"],
+    );
+    assert!(
+        impacted
+            .iter()
+            .any(|label| label == "//:consumer" || label == "@@//:consumer"),
+        "{impacted:?}"
+    );
+    assert!(!impacted.contains("//:control"), "{impacted:?}");
+}
+
 #[test]
 fn fine_grained_external_hashes_are_hermetic() {
     let first = copy_workspace("wrapped_external_repo");

tests/resources/workspaces/hidden_wrapper_external_repo/.bazelignore

@@ -0,0 +1,3 @@
+facade
+middle
+leaf

tests/resources/workspaces/hidden_wrapper_external_repo/BUILD

@@ -0,0 +1,22 @@
+# Reproducer workspace for https://github.com/Tinder/bazel-diff/issues/510.
+#
+# Shape:
+#   //:consumer --> @facade//:export
+#               --> @@middle+//:wrapped   (apparent name only inside facade)
+#               --> @leaf//:value
+#               --> @leaf//:value.txt
+#
+# Unlike wrapped_external_repo (#197), the root never declares `middle`: facade
+# pulls it in under the private apparent name `private_wrapper`, so `@middle`
+# and `@private_wrapper` are not valid from the root. When leaf/value.txt
+# changes with --fineGrainedHashExternalRepos=@leaf, //:consumer should be
+# impacted without the caller enumerating @facade and @@middle+ too.
+filegroup(
+    name = "consumer",
+    srcs = ["@facade//:export"],
+)
+
+filegroup(
+    name = "control",
+    srcs = ["control.txt"],
+)

tests/resources/workspaces/hidden_wrapper_external_repo/MODULE.bazel

@@ -0,0 +1,22 @@
+module(
+    name = "hidden_wrapper_external_repo_test",
+    version = "0.0.0",
+)
+
+bazel_dep(name = "facade", version = "1.0")
+bazel_dep(name = "leaf", version = "1.0")
+
+local_path_override(
+    module_name = "facade",
+    path = "facade",
+)
+
+local_path_override(
+    module_name = "middle",
+    path = "middle",
+)
+
+local_path_override(
+    module_name = "leaf",
+    path = "leaf",
+)

tests/resources/workspaces/hidden_wrapper_external_repo/control.txt

@@ -0,0 +1 @@
+unchanged

tests/resources/workspaces/hidden_wrapper_external_repo/facade/BUILD

@@ -0,0 +1,5 @@
+alias(
+    name = "export",
+    actual = "@private_wrapper//:wrapped",
+    visibility = ["//visibility:public"],
+)

tests/resources/workspaces/hidden_wrapper_external_repo/facade/MODULE.bazel

@@ -0,0 +1,6 @@
+module(
+    name = "facade",
+    version = "1.0",
+)
+
+bazel_dep(name = "middle", version = "1.0", repo_name = "private_wrapper")

tests/resources/workspaces/hidden_wrapper_external_repo/leaf/BUILD

@@ -0,0 +1,5 @@
+filegroup(
+    name = "value",
+    srcs = ["value.txt"],
+    visibility = ["//visibility:public"],
+)

tests/resources/workspaces/hidden_wrapper_external_repo/leaf/MODULE.bazel

@@ -0,0 +1,4 @@
+module(
+    name = "leaf",
+    version = "1.0",
+)

tests/resources/workspaces/hidden_wrapper_external_repo/leaf/value.txt

@@ -0,0 +1 @@
+before

tests/resources/workspaces/hidden_wrapper_external_repo/middle/BUILD

@@ -0,0 +1,5 @@
+alias(
+    name = "wrapped",
+    actual = "@leaf//:value",
+    visibility = ["//visibility:public"],
+)

tests/resources/workspaces/hidden_wrapper_external_repo/middle/MODULE.bazel

@@ -0,0 +1,6 @@
+module(
+    name = "middle",
+    version = "1.0",
+)
+
+bazel_dep(name = "leaf", version = "1.0")

tools/e2e/rust_e2e_cases.bzl

@@ -131,6 +131,14 @@ RUST_E2E_SUITES = [
                 "name": "regressions::hashes_are_hermetic_across_workspace_paths",
                 "timeout": "moderate",
             },
+            {
+                "name": "regressions::hidden_wrapper_external_repo_change_propagates_with_explicit_chain",
+                "timeout": "moderate",
+            },
+            {
+                "name": "regressions::hidden_wrapper_external_repo_change_reaches_main_consumer_reproducer_for_issue_510",
+                "timeout": "moderate",
+            },
             {
                 "name": "regressions::local_path_override_works_for_query_and_cquery",
                 "timeout": "moderate",