From 0b9aae421fe44af1ababe19b90e093e33d2dbefb Mon Sep 17 00:00:00 2001
From: Jan-Erik Rediger <jrediger@mozilla.com>
Date: Mon, 27 Jul 2026 13:13:53 +0200
Subject: [PATCH] CI: Run Rust tests on GhA

We start with a decision taks right from the get go:
We will run specific tasks only when the corresponding files have
changed.
That will speed up CI significantly.
E.g. typo fixes in docs or Python-only files won't trigger a full Kotlin run, nor does it trigger a Rust rebuild.

With this first change however we only migrate the Rust tests, those
only happen when *.rs files or Cargo files change
---
 .github/rust.json             | 44 ++++++++++++++++
 .github/workflows/crate-ci.sh | 13 ++++-
 .github/workflows/test.yml    | 96 +++++++++++++++++++++++++++++++++++
 3 files changed, 152 insertions(+), 1 deletion(-)
 create mode 100644 .github/rust.json
 create mode 100644 .github/workflows/test.yml

diff --git a/.github/rust.json b/.github/rust.json
new file mode 100644
index 0000000000..4793344dbe
--- /dev/null
+++ b/.github/rust.json
@@ -0,0 +1,44 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "cargo-common",
+      "pattern": [
+        {
+          "regexp": "^(warning|warn|error)(\\[(\\S*)\\])?: (.*)$",
+          "severity": 1,
+          "message": 4,
+          "code": 3
+        },
+        {
+          "regexp": "^\\s+-->\\s(\\S+):(\\d+):(\\d+)$",
+          "file": 1,
+          "line": 2,
+          "column": 3
+        }
+      ]
+    },
+    {
+      "owner": "cargo-test",
+      "pattern": [
+        {
+          "regexp": "^\\s+thread\\s+'(.*?)'.+panicked\\s+at\\s+([^:]+):(\\d+):(\\d+):$",
+          "message": 1,
+          "file": 2,
+          "line": 3,
+          "column": 4
+        }
+      ]
+    },
+    {
+      "owner": "cargo-fmt",
+      "pattern": [
+        {
+          "regexp": "^(Diff in ([^:]+):(\\d+)):$",
+          "message": 1,
+          "file": 1,
+          "line": 2
+        }
+      ]
+    }
+  ]
+}
diff --git a/.github/workflows/crate-ci.sh b/.github/workflows/crate-ci.sh
index 72125da0b8..cd64a6d3e2 100755
--- a/.github/workflows/crate-ci.sh
+++ b/.github/workflows/crate-ci.sh
@@ -21,6 +21,7 @@ Options:
     -f, --force     Force overwriting an existing binary
     --crate NAME    Name of the crate to install (default <repository name>)
     --tag TAG       Tag (version) of the crate to install (default <latest release>)
+    --filename      Filename (instead of $crate-$tag-$target.tar.gz).
     --target TARGET Install the release compiled for $TARGET (default <`rustc` host>)
     --to LOCATION   Where to install the binary (default ~/.cargo/bin)
 EOF
@@ -71,6 +72,10 @@ while test $# -gt 0; do
             tag=$2
             shift
             ;;
+        --filename)
+            filename=$2
+            shift
+            ;;
         --target)
             target=$2
             shift
@@ -148,7 +153,13 @@ fi
 
 say_err "Installing to: $dest"
 
-url="$url/download/$tag/$crate-$tag-$target.tar.gz"
+if [ -z "$filename" ]; then
+  filename="$crate-$tag-$target.tar.gz"
+fi
+
+url="$url/download/$tag/$filename"
+
+say_err "URL: $url"
 
 td=$(mktemp -d || mktemp -d -t tmp)
 curl -sL "$url" | tar xz -f - -C "$td"
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000000..021ecec9d3
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,96 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types:
+      - opened
+      - synchronize
+
+# Drop all default GITHUB_TOKEN permissions; each job declares its own least-privilege set.
+permissions: {}
+
+env:
+  MSRV: '1.90'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  decide-runs:
+    name: Decision task
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    outputs:
+      rust-changed: ${{ steps.set-flags.outputs.rust-changed }}
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          persist-credentials: false
+          filter: blob:none
+          fetch-depth: 0
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+      - id: changed-files-rust
+        uses: tj-actions/changed-files@9426d40962ed5378910ee2e21d5f8c6fcbf2dd96  # v47.0.6
+        with:
+          files: |
+            **/Cargo.toml
+            **/Cargo.lock
+            **/*.rs
+          base_sha: ${{ github.event.pull_request.base.sha || github.event.before }}
+      - name: Decide which jobs to run
+        id: set-flags
+        env:
+          RUST_CHANGED: ${{ steps.changed-files-rust.outputs.any_changed }}
+        run: |
+          echo "rust-changed=$RUST_CHANGED" >> $GITHUB_OUTPUT
+
+  test-rust:
+    runs-on: ubuntu-latest
+    needs: [decide-runs]
+    if: needs.decide-runs.outputs.rust-changed == 'true'
+    strategy:
+      fail-fast: false
+      matrix:
+        rust-version: ["stable", "1.90"]
+    steps:
+      - &checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          persist-credentials: false
+          filter: blob:none
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+
+      - name: Set up Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust-version }}
+
+      - name: Install nextest
+        run: |
+          .github/workflows/crate-ci.sh \
+            --git nextest-rs/nextest \
+            --crate nextest \
+            --tag "cargo-nextest-0.9.143" \
+            --filename "cargo-nextest-0.9.143-x86_64-unknown-linux-gnu.tar.gz"
+
+      - uses: Swatinem/rust-cache@c19371144df3bb44fab255c43d04cbc2ab54d1c4  # v2.9.1
+
+      - name: Install deps
+        run: |
+            sudo apt update
+            sudo apt install --yes --no-install-recommends \
+              faketime
+
+      - name: Test
+        run: |
+          export RUST_BACKTRACE=1
+          export RUST_LOG=glean_core=debug
+          export CARGO_INCREMENTAL=0
+
+          echo "::add-matcher::.github/rust.json"
+          make test-rust