Added github action to publish cargo-bazel binaries. (#2134)

closes #2131

.github/workflows/cargo_bazel_release.yaml

@@ -0,0 +1,47 @@
+---
+name: Release Cargo-bazel
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+    paths:
+      - crate_universe/version.bzl
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  validation:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      # TODO: Unfortunately it's not obvious how to restrict `workflow_dispatch` to a particular branch
+      # so this step ensures releases are always done off of `main`.
+      - name: Ensure branch is 'main'
+        run: |
+          git fetch origin &> /dev/null
+          branch="$(git rev-parse --abbrev-ref HEAD)"
+          if [[ "${branch}" != "main" ]]; then
+            echo "The release branch must be main. Got '${branch}'' instead." >&2
+            exit 1
+          else
+            echo "Branch is '${branch}'"
+          fi
+  builds:
+    needs: validation
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install rust toolchains for host
+        run: |
+          # Detect the current version of rust
+          version="$(grep 'DEFAULT_RUST_VERSION =' ./rust/private/common.bzl | grep -o '[[:digit:].]\+')"
+          rustup override set "${version}"
+          rustup update stable && rustup default stable
+      - name: Publish to crates.io
+        run: cargo publish --token ${CRATES_TOKEN}
+        working-directory: ./crate_universe
+        env:
+          CRATES_TOKEN: ${{ secrets.CRATES_TOKEN }}

crate_universe/BUILD.bazel

@@ -131,6 +131,20 @@ rust_test(
     ),
 )
 
+rust_test(
+    name = "versions_test",
+    srcs = ["tests/version_test.rs"],
+    data = [
+        "Cargo.toml",
+        "version.bzl",
+    ],
+    edition = "2021",
+    rustc_env = {
+        "CARGO_TOML": "$(rootpath :Cargo.toml)",
+        "VERSION_BZL": "$(rootpath :version.bzl)",
+    },
+)
+
 rust_doc(
     name = "rustdoc",
     crate = ":cargo_bazel",

crate_universe/tests/version_test.rs

@@ -0,0 +1,44 @@
+//! A small test binary for ensuring the version of the rules matches the binary version
+
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+
+#[test]
+fn test_cargo_and_bazel_versions() {
+    // Parse the version field from the `cargo-bazel` Cargo.toml file
+    let cargo_version = {
+        let cargo_path = PathBuf::from(env!("CARGO_TOML"));
+        let file = File::open(cargo_path).expect("Failed to load Cargo.toml file");
+        BufReader::new(file)
+            .lines()
+            .flatten()
+            .find(|line| line.contains("version = "))
+            .map(|line| {
+                line.trim()
+                    .replace("version = ", "")
+                    .trim_matches('\"')
+                    .to_owned()
+            })
+            .expect("The version.bzl file should have a line with `version = `")
+    };
+
+    // Parse the version global from the Bazel module
+    let bazel_version = {
+        let bazel_path = PathBuf::from(env!("VERSION_BZL"));
+        let file = File::open(bazel_path).expect("Failed to load versions.bzl file");
+        BufReader::new(file)
+            .lines()
+            .flatten()
+            .find(|line| line.contains("VERSION = "))
+            .map(|line| {
+                line.trim()
+                    .replace("VERSION = ", "")
+                    .trim_matches('\"')
+                    .to_owned()
+            })
+            .expect("The version.bzl file should have a line with `VERSION = `")
+    };
+
+    assert_eq!(cargo_version, bazel_version, "make sure `//crate_universe:version.bzl` and `//crate_universe:Cargo.toml` have matching versions.");
+}

crate_universe/version.bzl

@@ -1,3 +1,3 @@
 """ Version info for the `cargo-bazel` repository """
 
-VERSION = "0.8.0"
+VERSION = "0.9.0"