fix: simplify coverage summary generation, apply action lint

.github/workflows/rust-coverage.yml

@@ -55,13 +55,4 @@ jobs:
 
       # Convert the generated coverage report into overall and per-file summaries and add them to the GitHub job summary
       - name: Coverage summary
-        run: |
-          echo "### Test Coverage Report" >> $GITHUB_STEP_SUMMARY
-          echo "" >> $GITHUB_STEP_SUMMARY
-          ./.shared/scripts/coverage/coverage_summary.sh < /tmp/coverage.json >> $GITHUB_STEP_SUMMARY
-          echo "" >> $GITHUB_STEP_SUMMARY
-          echo "<details><summary>Per-file coverage</summary>" >> $GITHUB_STEP_SUMMARY
-          echo "" >> $GITHUB_STEP_SUMMARY
-          ./.shared/scripts/coverage/coverage_per_file.sh < /tmp/coverage.json >> $GITHUB_STEP_SUMMARY
-          echo "" >> $GITHUB_STEP_SUMMARY
-          echo "</details>" >> $GITHUB_STEP_SUMMARY
+        run: ./.shared/scripts/coverage/coverage_report.sh < /tmp/coverage.json >> "$GITHUB_STEP_SUMMARY"

scripts/coverage/coverage_report.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Generate coverage report in markdown format from cargo-llvm-cov JSON output.
+# Reads cargo-llvm-cov JSON output from stdin and outputs markdown to stdout
+# Usage: cargo llvm-cov --json ... | ./scripts/coverage/coverage_report.sh
+
+
+set -euo pipefail
+
+echo "### Test Coverage Report"
+echo ""
+
+# Overall coverage summary
+jq -r '
+  .data[0].totals |
+  "| Metric | Covered | Total | Coverage |",
+  "| ------ | ------: | ----: | -------: |",
+  "| Lines | \(.lines.covered) | \(.lines.count) | \(.lines.percent * 100 | round / 100)% |",
+  "| Functions | \(.functions.covered) | \(.functions.count) | \(.functions.percent * 100 | round / 100)% |",
+  "| Regions | \(.regions.covered) | \(.regions.count) | \(.regions.percent * 100 | round / 100)% |",
+  "| Instantiations | \(.instantiations.covered) | \(.instantiations.count) | \(.instantiations.percent * 100 | round / 100)% |"
+'
+
+echo ""
+echo "<details><summary>Per-file coverage</summary>"
+echo ""
+
+# Per-file coverage table
+jq -r '
+  "| File | Lines | Functions | Regions | Line Coverage |",
+  "| ---- | ----: | --------: | ------: | -----------: |",
+  (.data[0].files | sort_by(-.summary.lines.percent) | .[] |
+    .filename as $f |
+    .summary |
+    "| \($f | split("/") | .[-3:] | join("/")) | \(.lines.covered)/\(.lines.count) | \(.functions.covered)/\(.functions.count) | \(.regions.covered)/\(.regions.count) | \(.lines.percent * 100 | round / 100)% |"
+  )
+'
+
+echo ""
+echo "</details>"