ci: make code coverage dynamic

.codecov.yml

@@ -1,6 +1,10 @@
 comment:
   layout: "condensed_header, diff, flags, components"
 
+flag_management:
+  default_rules:
+    carryforward: true
+
 component_management:
   individual_components:
     - component_id: crashtracker  # this is an identifier that should not be changed

.github/actions/Cargo.toml

@@ -4,7 +4,7 @@
 [workspace]
 members = [
     "ci-shared",
-    "ci-crates",
+    "crates-reporter",
     "clippy-annotation-reporter",
 ]
 resolver = "2"

.github/actions/ci-shared/Cargo.toml

@@ -10,6 +10,7 @@ publish = false
 
 [dependencies]
 anyhow = "1.0"
+cargo_metadata = "0.23.1"
 log = "0.4"
 toml = "0.8"
 serde = { version = "1", features = ["derive"] }

.github/actions/ci-crates/src/git.rs → .github/actions/ci-shared/src/git.rs

@@ -4,7 +4,6 @@
 use anyhow::{bail, Context, Result};
 use std::process::Command;
 
-/// Run `git fetch --depth=1 origin <base_ref>` to ensure the base ref is available locally.
 pub fn fetch_base(base_ref: &str) -> Result<()> {
     log::info!("Fetching base branch: {base_ref}");
 
@@ -18,16 +17,12 @@ pub fn fetch_base(base_ref: &str) -> Result<()> {
         .context("Failed to run git fetch")?;
 
     if !status.success() {
-        // Non-fatal: warn but do not abort (mirrors `|| true` in the bash version)
         log::warn!("git fetch for {base_ref} returned non-zero exit code; continuing");
     }
 
     Ok(())
 }
 
-/// Return the list of files changed between `origin/<base_ref>...HEAD` (three-dot diff).
-///
-/// Uses `git diff --name-only origin/<base_ref>...HEAD`.
 pub fn changed_files(base_ref: &str) -> Result<Vec<String>> {
     let output = Command::new("git")
         .args(["diff", "--name-only", &format!("origin/{base_ref}...HEAD")])

.github/actions/ci-shared/src/lib.rs

@@ -3,3 +3,5 @@
 
 pub mod crate_detection;
 pub mod github_output;
+pub mod git;
+pub mod workspace;

.github/actions/ci-crates/src/workspace.rs → .github/actions/ci-shared/src/workspace.rs

@@ -9,7 +9,6 @@ use std::collections::{HashMap, HashSet, VecDeque};
 /// Parsed workspace metadata with reverse-dependency index.
 pub struct WorkspaceMetadata {
     packages: Vec<Package>,
-    /// Maps each crate name to the list of workspace crates that depend on it.
     reverse_deps: HashMap<String, Vec<String>>,
     workspace_root: Utf8PathBuf,
 }
@@ -105,8 +104,6 @@ mod tests {
         s.iter().map(|s| s.to_string()).collect()
     }
 
-    // --- affected_from ---
-
     #[test]
     fn affected_from_empty_seeds_returns_empty() {
         let meta = make_meta(&[]);
@@ -171,8 +168,6 @@ mod tests {
         );
     }
 
-    // --- load() integration ---
-
     #[test]
     fn load_returns_non_empty_workspace() {
         let meta = load().expect("load() should succeed against the real workspace");

.github/actions/clippy-annotation-reporter/src/commenter.rs

@@ -7,7 +7,7 @@
 //! including finding existing comments and updating or creating comments.
 
 use anyhow::{Context as _, Result};
-use log::{error, info};
+use log::info;
 use octocrab::Octocrab;
 
 /// Post or update a comment on a PR with the given report

.github/actions/ci-crates/Cargo.toml → .github/actions/crates-reporter/Cargo.toml

@@ -2,16 +2,15 @@
 # SPDX-License-Identifier: Apache-2.0
 
 [package]
-name = "ci-crates"
+name = "crates-reporter"
 version = "0.1.0"
 edition = "2021"
 rust-version = "1.84.1"
+description = "GitHub Action for reporting modified crates and transitive dependencies"
+homepage = "https://github.com/DataDog/libdatadog/tree/main/.github/actions/changed-crates"
+repository = "https://github.com/DataDog/libdatadog/tree/main/.github/actions/changed-crates"
 publish = false
 
-[[bin]]
-name = "changed-crates"
-path = "src/bin/changed_crates.rs"
-
 [dependencies]
 ci-shared = { path = "../ci-shared" }
 anyhow = "1.0"

.github/actions/changed-crates/action.yml → .github/actions/crates-reporter/action.yml

@@ -45,7 +45,7 @@ runs:
       shell: bash
       run: |
         cd ${{ github.action_path }}/..
-        cargo build --release -p ci-crates
+        cargo build --release -p crates-reporter
 
     - name: Run change reporter
       id: detect
@@ -58,7 +58,7 @@ runs:
           echo "status=skipped" >> $GITHUB_OUTPUT
           exit 0
         fi
-        if RUST_LOG=debug ${{ github.action_path }}/../target/release/changed-crates $PR_BASE_REF; then
+        if RUST_LOG=debug ${{ github.action_path }}/../target/release/crates-reporter $PR_BASE_REF; then
           echo "status=success" >> $GITHUB_OUTPUT
         else
           echo "status=skipped" >> $GITHUB_OUTPUT

.github/actions/ci-crates/src/bin/changed_crates.rs → .github/actions/crates-reporter/src/main.rs

@@ -14,15 +14,14 @@
 use anyhow::{anyhow, Result};
 use cargo_metadata::camino::Utf8Path;
 use cargo_metadata::Package;
-use ci_crates::git;
-use ci_crates::workspace;
+use ci_shared::git;
+use ci_shared::workspace;
 use ci_shared::crate_detection::CrateInfo;
 use ci_shared::github_output::set_output;
 use std::collections::HashSet;
 
 fn main() -> Result<()> {
     env_logger::init();
-    // Parse args
     let args: Vec<String> = std::env::args().collect();
     if args.len() < 2 {
         return Err(anyhow!("A reference base needs to be passed"));
@@ -35,13 +34,6 @@ fn main() -> Result<()> {
     let changed_files = git::changed_files(&base_ref)?;
     log::info!("Changed files: {:?}", changed_files);
 
-    // TODO: Check heuristics when workspace manifest (Cargo.toml) or config.toml changed. This could indicate a
-    // change in:
-    // * Rust version.
-    // * Edition.
-    // * Profile.
-    // * Compilation flags.
-
     let workspace = workspace::load()?;
     let changed_crates = collect_changed_crates(&changed_files, workspace.members(), workspace.workspace_root());
 

.github/workflows/coverage.yml

@@ -1,13 +1,62 @@
 name: Coverage
 
 on:
-  pull_request:
   push:
     branches:
+      # Allowing to generate coverage when pushes are made to main in order to generate all independent crate reports
+      # so we can establish a proper baseline without manual intervention or a manual workflow dispatch.
       - main
+  pull_request:
+    types: ['opened', 'edited', 'reopened', 'synchronize']
+    branches-ignore:
+      - "v[0-9]+.[0-9]+.[0-9]+.[0-9]+"
+      - release
 
 jobs:
+  setup:
+    runs-on: ubuntu-latest
+    outputs:
+      packages: ${{ steps.set-packages.outputs.packages }}
+      packages-count: ${{ steps.set-packages.outputs.packages-count }}
+      crates-json: ${{ steps.set-packages.outputs.crates-json }}
+    steps:
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # 4.2.2
+      with:
+        fetch-depth: 0
+    - name: Get changed crates
+      if: ${{ github.event_name == 'pull_request' }}
+      id: changed-crates
+      uses: ./.github/actions/changed-crates
+    - name: Set packages to get coverage
+      id: set-packages
+      env:
+        CHANGED_CRATES_COUNT: ${{ steps.changed-crates.outputs.crates_count }}
+        AFFECTED_CRATES: ${{ steps.changed-crates.outputs.affected_crates }}
+      run: |
+        if [[ "${{ github.event_name }}" == "push" ]]; then
+          COUNT="1"
+          PACKAGES=""
+          CRATES_JSON=""
+        elif [[ "$CHANGED_CRATES_COUNT" == "0" ]]; then
+          COUNT="0"
+          PACKAGES=""
+          CRATES_JSON=""
+        else
+          COUNT=$(echo "$AFFECTED_CRATES" | jq 'length')
+          PACKAGES=$(echo "$AFFECTED_CRATES" | jq -r 'map("-p " + .) | join(" ")')
+          CRATES_JSON="$AFFECTED_CRATES"
+        fi
+        echo "packages-count=$COUNT" >> $GITHUB_OUTPUT
+        echo "packages=$PACKAGES" >> $GITHUB_OUTPUT
+        {
+          echo "crates-json<<EOF"
+          echo "$CRATES_JSON"
+          echo "EOF"
+        } >> $GITHUB_OUTPUT
+
   coverage:
+    needs: setup
+    if: needs.setup.outputs.packages-count != '0'
     runs-on:
       labels: ubuntu-latest-16-cores
       group: APM Larger Runners
@@ -40,13 +89,54 @@ jobs:
           cache-targets: true # cache build artifacts
           cache-bin: true # cache the ~/.cargo/bin directory
       - name: Generate code coverage (including doc tests)
+        env:
+          PACKAGES: ${{ needs.setup.outputs.packages }}
+          CRATES_JSON: ${{ needs.setup.outputs.crates-json }}
         run: |
-          cargo llvm-cov --all-features --workspace --no-report nextest
-          cargo llvm-cov --all-features --workspace --no-report --doc
-          cargo llvm-cov report --doctests --lcov --output-path lcov.info
+          if [[ -z "$PACKAGES" ]]; then
+            cargo llvm-cov --all-features --workspace --no-report nextest
+            cargo llvm-cov --all-features --workspace --no-report --doc
+            CRATES_JSON=$(cargo metadata --no-deps --format-version 1 | jq '[.packages[].name]')
+          else
+            # shellcheck disable=SC2086 - word splitting on $PACKAGES is intentional
+            cargo llvm-cov --all-features --no-report nextest $PACKAGES
+            # shellcheck disable=SC2086
+            cargo llvm-cov --all-features --no-report --doc $PACKAGES
+          fi
+          for crate in $(echo "$CRATES_JSON" | jq -r '.[]'); do
+            if ! cargo llvm-cov report --doctests --lcov \
+                --output-path "lcov-${crate}.info" \
+                --package "${crate}"; then
+              if [[ -s "lcov-${crate}.info" ]]; then
+                echo "::error::Coverage report generation failed for ${crate}"
+                exit 1
+              else
+                echo "No coverage data for ${crate}, skipping"
+              fi
+            fi
+          done
+          {
+            echo "CRATES_JSON_COMPUTED<<EOF"
+            echo "$CRATES_JSON"
+            echo "EOF"
+          } >> "$GITHUB_ENV"
+      - name: Install Codecov CLI
+        run: |
+          curl -Os https://cli.codecov.io/v10.4.0/linux/codecov
+          curl -Os https://cli.codecov.io/v10.4.0/linux/codecov.SHA256SUM
+          echo "0f7aadde579ebde1443ad2f977beada703f562997fdda603f213faf2a8559868  codecov" | shasum -a 256 -c
+          chmod +x codecov
+          sudo mv codecov /usr/local/bin/codecov
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@5a1091511ad55cbe89839c7260b706298ca349f7 # 5.5.1
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: lcov.info
-          fail_ci_if_error: true
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        run: |
+          for crate in $(echo "$CRATES_JSON_COMPUTED" | jq -r '.[]'); do
+            if [[ -s "lcov-${crate}.info" ]]; then
+              codecov upload-process \
+                --token "$CODECOV_TOKEN" \
+                --file "lcov-${crate}.info" \
+                --flag "${crate}" \
+                --fail-on-error
+            fi
+          done