rust: Add rust tests to bazelisk

.bazeliskrc

@@ -3,3 +3,5 @@
 # Set the version of Bazel to use.
 # TODO: #642 -- Update once the JS bazelbuild/rules_closure supports bazel modules.
 USE_BAZEL_VERSION=7.4.1
+# Use lld linker for rust since gold is deprecated and has known bugs.
+build --linkopt=-fuse-ld=lld

BUILD

@@ -0,0 +1 @@
+# Required for rules_rust configuration.

MODULE.bazel

@@ -5,9 +5,20 @@ module(
 
 # bazel-skylib required by #@io_bazel_rules_closure.
 # https://github.com/bazelbuild/bazel-skylib
-bazel_dep(name = "bazel_skylib", version = "1.7.1")
+bazel_dep(name = "bazel_skylib", version = "1.8.2")
 
 # googletest required by c/BUILD.
 # https://github.com/google/googletest
 bazel_dep(name = "googletest", version = "1.15.2")
 
+bazel_dep(name = "rules_rust", version = "0.69.0")
+
+bazel_dep(name = "protobuf", version = "27.0", repo_name = "com_google_protobuf")
+
+crate = use_extension("@rules_rust//crate_universe:extension.bzl", "crate")
+crate.from_cargo(
+    name = "crates",
+    cargo_lockfile = "//rust:Cargo.lock",
+    manifests = ["//rust:Cargo.toml"],
+)
+use_repo(crate, "crates")

rust/BUILD

@@ -0,0 +1,34 @@
+load("@rules_rust//rust:defs.bzl", "rust_library", "rust_test")
+load("@crates//:defs.bzl", "all_crate_deps")
+
+rust_library(
+    name = "open_location_code",
+    srcs = [
+        "src/lib.rs",
+        "src/codearea.rs",
+        "src/consts.rs",
+        "src/interface.rs",
+        "src/private.rs",
+    ],
+    deps = all_crate_deps(
+        normal = True,
+    ),
+    visibility = ["//visibility:private"],
+)
+
+rust_test(
+    name = "all_test",
+    size = "small",
+    srcs = [
+        "tests/all_test.rs",
+        "tests/csv_reader.rs",
+    ],
+    data = ["//test_data"],
+    deps = [
+        ":open_location_code",
+    ] + all_crate_deps(
+        normal = True,
+        normal_dev = True,
+    ),
+    visibility = ["//visibility:private"],
+)

rust/tests/all_test.rs

@@ -19,7 +19,7 @@ use rand::random_range;
 #[test]
 fn is_valid_test() {
     let mut tested = 0;
-    for line in CSVReader::new("validityTests.csv") {
+    for line in CSVReader::new("validityTests.csv").unwrap() {
         let cols: Vec<&str> = line.split(',').collect();
         let code = cols[0];
         let _valid = cols[1] == "true";
@@ -38,7 +38,7 @@ fn is_valid_test() {
 #[test]
 fn decode_test() {
     let mut tested = 0;
-    for line in CSVReader::new("decoding.csv") {
+    for line in CSVReader::new("decoding.csv").unwrap() {
         let cols: Vec<&str> = line.split(',').collect();
         let code = cols[0];
         let len = cols[1].parse::<usize>().unwrap();
@@ -65,7 +65,7 @@ fn encode_test() {
     let mut errors = 0;
     // Allow a small proportion of errors due to floating point.
     let allowed_error_rate = 0.05;
-    for line in CSVReader::new("encoding.csv") {
+    for line in CSVReader::new("encoding.csv").unwrap() {
         if line.chars().count() == 0 {
             continue;
         }
@@ -97,7 +97,7 @@ fn encode_test() {
 #[test]
 fn point_to_integers_test() {
     let mut tested = 0;
-    for line in CSVReader::new("encoding.csv") {
+    for line in CSVReader::new("encoding.csv").unwrap() {
         if line.chars().count() == 0 {
             continue;
         }
@@ -131,7 +131,7 @@ fn point_to_integers_test() {
 #[test]
 fn encode_integers_test() {
     let mut tested = 0;
-    for line in CSVReader::new("encoding.csv") {
+    for line in CSVReader::new("encoding.csv").unwrap() {
         if line.chars().count() == 0 {
             continue;
         }
@@ -158,7 +158,7 @@ fn encode_integers_test() {
 #[test]
 fn shorten_recovery_test() {
     let mut tested = 0;
-    for line in CSVReader::new("shortCodeTests.csv") {
+    for line in CSVReader::new("shortCodeTests.csv").unwrap() {
         let cols: Vec<&str> = line.split(',').collect();
         let full_code = cols[0];
         let lat = cols[1].parse::<f64>().unwrap();

rust/tests/csv_reader.rs

@@ -1,20 +1,43 @@
 use std::env::current_dir;
 use std::fs::File;
-use std::io::{BufRead, BufReader, Lines};
+use std::io::{BufRead, BufReader, Lines, Error};
+use std::io::ErrorKind::InvalidInput;
+use std::path::PathBuf;
 
 pub struct CSVReader {
     iter: Lines<BufReader<File>>,
 }
 
 impl CSVReader {
-    pub fn new(csv_name: &str) -> CSVReader {
+    pub fn new(csv_name: &str) -> Result<CSVReader, Error> {
         // Assumes we're called from <open-location-code root>/rust
-        let project_root = current_dir().unwrap();
-        let olc_root = project_root.parent().unwrap();
+        let project_root = current_dir()?;
+
+        let olc_root: PathBuf = match project_root.file_name().and_then(|n| n.to_str()) {
+            Some("rust") => project_root
+                .parent()
+                .map(|p| p.to_path_buf())
+                .ok_or_else(|| Error::new(InvalidInput, "Could not find project root parent")),
+            Some("_main") => Ok(project_root.clone()),
+            _ => {
+                return Err(Error::new(InvalidInput, format!(
+                    "Expected current dir to end with 'rust' or '_main', got {:?}",
+                    project_root
+                )));
+            }
+        }?;
         let csv_path = olc_root.join("test_data").join(csv_name);
-        CSVReader {
-            iter: BufReader::new(File::open(csv_path).unwrap()).lines(),
-        }
+
+        let file = File::open(&csv_path).map_err(|e| {
+            Error::new(e.kind(), format!(
+                "Failed to open CSV file at {:?}: {} (Current dir: {:?})",
+                csv_path, e, project_root
+            ))
+        })?;
+
+        Ok(CSVReader {
+            iter: BufReader::new(file).lines(),
+        })
     }
 }