workflows/check: Add test code coverage by RobertZ2011 · Pull Request #763 · OpenDevicePartnership/embedded-services

RobertZ2011 · 2026-03-25T23:44:53Z

No description provided.

Copilot

Pull request overview

This PR extends the existing CI “check” workflow by adding Rust test code coverage generation and uploading the resulting HTML report as a workflow artifact.

Changes:

Attempts to install LLVM coverage tooling for the Rust toolchain.
Runs cargo test with coverage instrumentation enabled.
Adds steps to merge raw profiles, generate an HTML coverage report via grcov, and upload it as an artifact.

Copilot · 2026-03-25T23:47:41Z

.github/workflows/check.yml

          submodules: true
      - name: Install stable
        uses: dtolnay/rust-toolchain@stable
+        components: llvm-tools


dtolnay/rust-toolchain step inputs must be under with:. As written, components: llvm-tools is not passed to the action, so the LLVM tools (and rust-profdata) likely won’t be installed and later coverage steps will fail. Move the component under with: (and ensure the correct rustup component name is used for rust-profdata).

Suggested change

components: llvm-tools

with:

components: llvm-tools-preview

Copilot · 2026-03-25T23:47:41Z

.github/workflows/check.yml

      - name: cargo test
        run: cargo test --locked
+        env:
+          RUSTFLAGS: '-C instrument-coverage'


Coverage instrumentation sets RUSTFLAGS=-C instrument-coverage, but LLVM_PROFILE_FILE isn’t set. Without a per-process filename pattern, test binaries can overwrite the same .profraw, producing incomplete/incorrect coverage data. Set LLVM_PROFILE_FILE to a unique pattern (e.g., including %p/%m) and preferably write it into a known directory under target/.

Copilot · 2026-03-25T23:47:42Z

.github/workflows/check.yml

+      - name: Install rustfilt
+        run: cargo install rustfilt
+      - name : Merge raw profiles
+        run: rust-profdata merge -sparse *.profraw -o coverage.profdata


The merge step assumes .profraw files exist in the repo root (*.profraw). Depending on where the tests run and how profiling output is configured, the files may be emitted elsewhere (or not match the glob), causing this step to fail. Consider merging from the directory you configure via LLVM_PROFILE_FILE, or using find to collect the .profraw inputs robustly.

Suggested change

run: rust-profdata merge -sparse *.profraw -o coverage.profdata

run: rust-profdata merge -sparse $(find . -name '*.profraw' -print) -o coverage.profdata

Copilot · 2026-03-25T23:47:42Z

.github/workflows/check.yml

+      - name: Install grcov
+        run: cargo install grcov
+      - name: Install rustfilt
+        run: cargo install rustfilt


Installing grcov and rustfilt via cargo install without pinning versions makes CI non-reproducible and can break when upstream releases change. Prefer pinning --version (and --locked) or using an install action (e.g., taiki-e/install-action) to get consistent binaries and faster runs via caching.

Suggested change

- name: Install grcov

run: cargo install grcov

- name: Install rustfilt

run: cargo install rustfilt

- name: Install grcov and rustfilt

uses: taiki-e/install-action@v2

with:

tool: grcov,rustfilt

tool-version: 0.8.18,0.2.1

Copilot

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

Copilot · 2026-03-26T00:00:34Z

.github/workflows/check.yml

+        run: rust-profdata merge -sparse *.profraw -o coverage.profdata
+      - name: Generate code coverage report
+        run: |
+          grcov . --binary-path ./target/debug/ -s . -t html --ignore-not-existing -o ./target/debug/coverage/ coverage.profdata


The grcov invocation is generating a report from an LLVM .profdata, but it doesn't pass LLVM-specific options and only points --binary-path at ./target/debug/ (test binaries usually live under target/debug/deps). As written this can produce an empty/incomplete report. Consider enabling LLVM mode in grcov and including the deps directory (or otherwise pointing grcov at the actual test binaries used to generate the profiles).

Suggested change

grcov . --binary-path ./target/debug/ -s . -t html --ignore-not-existing -o ./target/debug/coverage/ coverage.profdata

grcov . \

--binary-path ./target/debug/ \

--binary-path ./target/debug/deps/ \

-s . \

-t html \

--llvm \

--ignore-not-existing \

-o ./target/debug/coverage/ \

coverage.profdata

Copilot · 2026-03-26T00:00:34Z

.github/workflows/check.yml

      - name: cargo test
        run: cargo test --locked
+        env:
+          RUSTFLAGS: '-C instrument-coverage'


-C instrument-coverage relies on LLVM profile output files; without setting LLVM_PROFILE_FILE to a unique pattern (e.g., including %p), parallel cargo test processes can overwrite/corrupt the same .profraw and make coverage flaky/incorrect. Set LLVM_PROFILE_FILE (and consider CARGO_INCREMENTAL=0) in this step's env so all profiles are written deterministically to a known directory.

Suggested change

RUSTFLAGS: '-C instrument-coverage'

RUSTFLAGS: '-C instrument-coverage'

LLVM_PROFILE_FILE: 'default-%p-%m.profraw'

CARGO_INCREMENTAL: '0'

Copilot · 2026-03-26T00:00:35Z

.github/workflows/check.yml

+      - name : Merge raw profiles
+        run: rust-profdata merge -sparse *.profraw -o coverage.profdata


This step installs llvm-tools-preview but merges profiles using rust-profdata. For clarity/portability across toolchains, prefer using the LLVM tool name (llvm-profdata) that is provided by the component, and make the input glob/path match wherever LLVM_PROFILE_FILE writes the .profraw files.

Copilot

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

Copilot · 2026-03-26T00:17:48Z

.github/workflows/check.yml

+          name: code-coverage-report
+          path: ./target/debug/coverage/



grcov typically needs LLVM mode enabled when consuming .profraw/.profdata generated by -C instrument-coverage; otherwise it may not interpret the profile data correctly and can produce an empty/incorrect report. Consider adding the appropriate LLVM flag(s) for grcov when generating the HTML report.

Copilot · 2026-03-26T00:17:49Z

.github/workflows/check.yml

+        uses: actions/upload-artifact@v4
+        with:


Minor YAML style: this step uses - name : whereas the rest of the workflow uses - name:. Consider normalizing formatting for consistency/readability.

Copilot AI review requested due to automatic review settings March 25, 2026 23:44

RobertZ2011 self-assigned this Mar 25, 2026

Copilot started reviewing on behalf of RobertZ2011 March 25, 2026 23:45 View session

Copilot AI reviewed Mar 25, 2026

View reviewed changes

RobertZ2011 force-pushed the test-coverage-report branch from 4bd6053 to 5e295dc Compare March 25, 2026 23:49

Copilot AI review requested due to automatic review settings March 25, 2026 23:56

RobertZ2011 force-pushed the test-coverage-report branch from 5e295dc to e40955b Compare March 25, 2026 23:56

Copilot started reviewing on behalf of RobertZ2011 March 25, 2026 23:57 View session

Copilot AI reviewed Mar 26, 2026

View reviewed changes

RobertZ2011 force-pushed the test-coverage-report branch 2 times, most recently from 66036c8 to 950eb34 Compare March 26, 2026 00:04

Copilot AI review requested due to automatic review settings March 26, 2026 00:04

Copilot started reviewing on behalf of RobertZ2011 March 26, 2026 00:04 View session

RobertZ2011 force-pushed the test-coverage-report branch 2 times, most recently from 15d3fa4 to b4b6053 Compare March 26, 2026 00:17

Copilot AI reviewed Mar 26, 2026

View reviewed changes

workflows/check: Add test code coverage

d8a8f6b

RobertZ2011 force-pushed the test-coverage-report branch from b4b6053 to d8a8f6b Compare March 26, 2026 00:23

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

workflows/check: Add test code coverage#763

workflows/check: Add test code coverage#763
RobertZ2011 wants to merge 1 commit intoOpenDevicePartnership:v0.2.0from
RobertZ2011:test-coverage-report

RobertZ2011 commented Mar 25, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 25, 2026

Uh oh!

Copilot AI Mar 25, 2026

Uh oh!

Copilot AI Mar 25, 2026

Uh oh!

Copilot AI Mar 25, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 26, 2026

Uh oh!

Copilot AI Mar 26, 2026

Uh oh!

Copilot AI Mar 26, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 26, 2026

Uh oh!

Copilot AI Mar 26, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

	run: rust-profdata merge -sparse *.profraw -o coverage.profdata
	run: rust-profdata merge -sparse $(find . -name '*.profraw' -print) -o coverage.profdata

-          grcov . --binary-path ./target/debug/ -s . -t html --ignore-not-existing -o ./target/debug/coverage/ coverage.profdata
+          grcov . \
+            --binary-path ./target/debug/ \
+            --binary-path ./target/debug/deps/ \
+            -s . \
+            -t html \
+            --llvm \
+            --ignore-not-existing \
+            -o ./target/debug/coverage/ \
+            coverage.profdata

		- name : Merge raw profiles
		run: rust-profdata merge -sparse *.profraw -o coverage.profdata

Conversation

RobertZ2011 commented Mar 25, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Mar 25, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 25, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 25, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 25, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Mar 26, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 26, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 26, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Mar 26, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 26, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants