Add test

.bazelci/presubmit.yml

@@ -583,6 +583,12 @@ tasks:
     test_flags:
       - "--@rules_rust//rust/toolchain/channel=nightly"
       - "--@rules_rust//:no_std=alloc"
+  bzlmod_repo_mapping_runfiles:
+    name: bzlmod repo mapping test
+    platform: ubuntu2004
+    working_directory: test/bzlmod_repo_mapping/module_a
+    test_targets:
+      - "//..."
   android_examples_ubuntu2004:
     name: Android Examples
     platform: ubuntu2004

.bazelignore

@@ -2,5 +2,6 @@ bzlmod
 docs
 examples
 crate_universe/private/bootstrap
+test/bzlmod_repo_mapping
 test/cc_common_link
 test/no_std

test/bzlmod_repo_mapping/README.md

@@ -0,0 +1,4 @@
+Bzlmod allow modules to rename their dependencies and use the aliased names in runfiles lookups.
+This test defines the following dependency tree: A -> B -> C. The test if whether a binary built in A
+that calls code in B that has an `rlocation!` call to lookup a runfile from C is able to correctly use
+B's repo_mapping. This is accomplished by having B use a custom `repo_name` for C.

test/bzlmod_repo_mapping/module_a/.gitignore

@@ -0,0 +1 @@
+bazel-*

test/bzlmod_repo_mapping/module_a/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
+
+rust_library(
+    name = "lib",
+    srcs = ["lib.rs"],
+    deps = ["@module_b//:lib_b"],
+)
+
+rust_test(
+    name = "lib_test",
+    crate = ":lib",
+)

test/bzlmod_repo_mapping/module_a/MODULE.bazel

@@ -0,0 +1,15 @@
+module(name = "module_a")
+
+local_path_override(module_name = "module_b", path = "../module_b")
+local_path_override(module_name = "module_c", path = "../module_c")
+
+bazel_dep(name = "module_b", version = "0.0.0")
+
+bazel_dep(name = "rules_rust", version = "0.0.0")
+local_path_override(module_name = "rules_rust", path = "../../..")
+
+rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
+rust.toolchain(edition = "2021")
+use_repo(rust, "rust_toolchains")
+
+register_toolchains("@rust_toolchains//:all")

test/bzlmod_repo_mapping/module_a/lib.rs

@@ -0,0 +1,8 @@
+#[cfg(test)]
+mod test {
+    #[test]
+    fn test_repo_remapping() {
+        let data = lib_b::read_file_from_module_c();
+        assert_eq!(data, "module(name = \"module_c\")");
+    }
+}

test/bzlmod_repo_mapping/module_b/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@rules_rust//rust:defs.bzl", "rust_library")
+
+rust_library(
+    name = "lib_b",
+    srcs = ["lib.rs"],
+    data = ["@aliased_c//:MODULE.bazel"],
+    deps = ["@rules_rust//tools/runfiles"],
+    visibility = ["//visibility:public"],
+)

test/bzlmod_repo_mapping/module_b/MODULE.bazel

@@ -0,0 +1,9 @@
+module(name = "module_b")
+
+bazel_dep(name = "module_c", version = "0.0.0", repo_name = "aliased_c")
+bazel_dep(name = "rules_rust", version = "0.0.0")
+rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
+rust.toolchain(edition = "2021")
+use_repo(rust, "rust_toolchains")
+
+register_toolchains("@rust_toolchains//:all")

test/bzlmod_repo_mapping/module_b/lib.rs

@@ -0,0 +1,6 @@
+use runfiles::Runfiles;
+
+pub fn read_file_from_module_c() -> String {
+    let r = Runfiles::create().unwrap();
+    std::fs::read_to_string(runfiles::rlocation!(r, "aliased_c/MODULE.bazel")).unwrap()
+}

test/bzlmod_repo_mapping/module_c/BUILD.bazel

@@ -0,0 +1 @@
+exports_files(["MODULE.bazel"])

test/bzlmod_repo_mapping/module_c/MODULE.bazel

@@ -0,0 +1 @@
+module(name = "module_c")

tools/runfiles/runfiles.rs

@@ -70,7 +70,7 @@ impl Runfiles {
     /// or a directory based Runfiles object otherwise.
     pub fn create() -> io::Result<Self> {
         let mode = if let Some(manifest_file) = std::env::var_os(MANIFEST_FILE_ENV_VAR) {
-            Self::create_manifest_based(&Path::new(&manifest_file))?
+            Self::create_manifest_based(Path::new(&manifest_file))?
         } else {
             Mode::DirectoryBased(find_runfiles_dir()?)
         };