build: ensure only one package's coverage is evaluated at a time

We were encountering a bug due to the HTML code coverage reports flattening their directory structure when all dependencies of the tested package reside in the same namespace
as the package itself.
While we could preserve the full project package structure with the  --all option, setting it would be too expensive. Hence, we instead only generate the test coverage for
the currently tested package by setting the appropriate c8 flags (for which the make command recipe had to be updated to accept custom flags) such that we can sidestep the
need to resolve the correct folder to upload to the code coverage repository, Our previous approach of finding the folder for the tested package was not satisfactory as it
didn't take the flattening behavior into account and the index.html file existence check was thus not always yielding the corect result.

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: passed
  - task: lint_typescript_declarations
    status: passed
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: Planeshifter

.github/workflows/scripts/run_tests_coverage

@@ -26,15 +26,8 @@
 #   file2        File name.
 #   file3        File name.
 #
-#
-# Environment variables:
-#
-#   GITHUB_REPO    GitHub repository.
-#   GITHUB_REF     GitHub branch or tag.
-#   LOG_FILE       Log file.
-#
 
-# shellcheck disable=SC2181,SC2153,SC2129
+# shellcheck disable=SC2181,SC2153,SC2129,SC2207,SC2317
 
 # Ensure that the exit status of pipelines is non-zero in the event that at least one of the commands in a pipeline fails:
 set -o pipefail
@@ -48,15 +41,6 @@ coverage_base_url="${COVERAGE_BASE_URL:-https://coverage.stdlib.io}"
 # Get the list of changed files:
 changed="$*"
 
-# Get the GitHub repository:
-github_repo="${GITHUB_REPO}"
-
-# Get the GitHub branch or tag:
-github_ref="${GITHUB_REF}"
-
-# Get the path to a log file as the third argument to the build script:
-log_file="${LOG_FILE}"
-
 # Define a heartbeat interval to periodically print messages in order to prevent CI from prematurely ending a build due to long running commands:
 heartbeat_interval='30s'
 
@@ -125,18 +109,18 @@ compare_cov() {
 
 	if [ "$old_cov_value" == 0 ]; then
 		new_cov_percentage=$(awk "BEGIN {printf \"%.2f\", $new_cov_value*100}")
-		echo "\$\\\\\\\\color{green}+$new_cov_percentage\\\\\\\\\\\\\\\\%\$"
+		printf "\$\\\\\\\\color{green}+%s\\\\\\\\\\\\\\\\%%\$\n" "$new_cov_percentage"
 	else
 		percentage_change=$(awk "BEGIN {printf \"%.2f\", (($new_cov_value - $old_cov_value) / $old_cov_value) * 100}")
 		color="green"
 		sign=""
-		if [ $(awk "BEGIN {if ($percentage_change >= 0) print 1; else print 0}") -eq 1 ]; then
+		if [ "$(awk "BEGIN {if ($percentage_change >= 0) print 1; else print 0}")" -eq 1 ]; then
 			sign="+"
-		elif [ $(awk "BEGIN {if ($percentage_change < 0) print 1; else print 0}") -eq 1 ]; then
+		elif [ "$(awk "BEGIN {if ($percentage_change < 0) print 1; else print 0}")" -eq 1 ]; then
 			sign="-"
 			color="red"
 		fi
-		echo "\$\\\\\\\\color{$color}$sign$percentage_change\\\\\\\\\\\\\\\\%\$"
+		printf "\$\\\\\\\\color{%s}%s%s\\\\\\\\\\\\\\\\%%\$\n" "$color" "$sign" "$percentage_change"
 	fi
 }
 
@@ -163,23 +147,15 @@ main() {
 	coverage=''
 	for package in ${directories}; do
 		# For each package, extract coverage values from the respective coverage report:
-		pkg=`echo $package | sed -E 's/^.*stdlib\///'`
+		pkg=$(echo "$package" | sed -E 's/^.*stdlib\///')
 
 		if [ -f "lib/node_modules/@stdlib/${pkg}/binding.gyp" ]; then
 			NODE_ADDONS_PATTERN="${pkg}" make install-node-addons
 		fi
 
-		make test-javascript-cov TESTS_FILTER=".*/${pkg}/test/.*"
+		make test-javascript-cov TESTS_FILTER=".*/${pkg}/test/.*" C8_FLAGS="-n 'lib/node_modules/@stdlib/${pkg}/**'"
 
-		if [ ! -f reports/coverage/lcov-report/${pkg}/lib/index.html ]; then
-			# Reports for packages with no dependencies are stored in the `lcov-report` directory
-			coverage_path="reports/coverage/lcov-report/index.html"
-			top_level_report=true
-		else
-			# Reports for packages with dependencies are stored in `lcov-report/<pkg>/lib`:
-			coverage_path="reports/coverage/lcov-report/${pkg}/lib/index.html"
-			top_level_report=false
-		fi
+		coverage_path="reports/coverage/lcov-report/index.html"
 		pkg_cov_values=($(cat $coverage_path | grep "fraction" | grep -oP '\d+/\d+' | awk -F'/' '{if ($2 != 0) print $1/$2; else print 1}'))
 		pkg_statements_cov=${pkg_cov_values[0]}
 		pkg_branches_cov=${pkg_cov_values[1]}
@@ -214,26 +190,22 @@ main() {
 		pkg_cov="| $pkg_statements_cov_fraction <br> $cov_change_statements | $pkg_branches_cov_fraction <br> $cov_change_branches | $pkg_functions_cov_fraction <br> $cov_change_functions | $pkg_lines_cov_fraction <br> $cov_change_lines |"
 
 		pkg_url="${coverage_base_url}/${pkg}/index.html"
-		pkg_link="<a href=\"$pkg_url\">$pkg</a>"
+		pkg_link="<a href=\"${pkg_url}\">${pkg}</a>"
 		coverage="$coverage\n| $pkg_link $pkg_cov"
 
 		# Copy coverage report of the package to artifacts directory:
-		if [ "$top_level_report" = true ]; then
-			mkdir -p "artifacts/${pkg}" && cp -r "reports/coverage/lcov-report"/* "artifacts/${pkg}/"
-		else
-			mkdir -p "artifacts/${pkg}/lib/" && cp -r "reports/coverage/lcov-report/${pkg}/lib"/* "artifacts/${pkg}/"
-		fi
+		mkdir -p "artifacts/${pkg}" && cp -r "reports/coverage/lcov-report"/* "artifacts/${pkg}/"
 
 		# Cleanup coverage reports for next package:
 		rm -rf reports/coverage/lcov-report/*
 	done
 
 	# Format coverage as Markdown table row:
-	table_body=`echo $coverage | sed -e 's/,/|/g; s/"/ /g; s/\[/|/g; s/\]/|/g'`
+	table_body=$(echo "$coverage" | sed -e 's/,/|/g; s/"/ /g; s/\[/|/g; s/\]/|/g')
 	table_header="| Package | Statements | Branches | Functions | Lines |\n| --------- | ------------ | ---------- | ----------- | ----- |"
 	table="${table_header}${table_body}"
 
-	echo "table=$table" >> $GITHUB_OUTPUT
+	echo "table=$table" >> "$GITHUB_OUTPUT"
 
 	cleanup
 	print_success

tools/make/lib/test-cov/c8.mk

@@ -49,14 +49,19 @@ C8_EXCLUDES_FLAGS = \
 	-x "**/$(CONFIG_FOLDER)/**" \
 	-x "**/$(DOCUMENTATION_FOLDER)/**"
 
+# Define user-supplied command-line options:
+C8_FLAGS ?=
+
 # Define command-line options when generating coverage data:
-C8_FLAGS = \
+c8_flags = \
 	$(C8_EXCLUDES_FLAGS) \
 	--clean=false \
 	--temp-directory $(COVERAGE_DIR)/tmp \
 	--report-dir $(COVERAGE_DIR) \
 	--reporter lcov
 
+# Append user-supplied command-line options:
+c8_flags += $(C8_FLAGS)
 
 # RULES #
 
@@ -87,7 +92,7 @@ ifeq ($(FAIL_FAST), true)
 		NODE_ENV="$(NODE_ENV_TEST)" \
 		NODE_PATH="$(NODE_PATH_TEST)" \
 		TEST_MODE=coverage \
-		$(C8) $(C8_FLAGS) $(NODE) $$test | $(TAP_REPORTER) || exit 1; \
+		$(C8) $(c8_flags) $(NODE) $$test | $(TAP_REPORTER) || exit 1; \
 	done
 else
 	$(QUIET) $(FIND_TESTS_CMD) | grep '^[\/]\|^[a-zA-Z]:[/\]' | while read -r test; do \
@@ -96,7 +101,7 @@ else
 		NODE_ENV="$(NODE_ENV_TEST)" \
 		NODE_PATH="$(NODE_PATH_TEST)" \
 		TEST_MODE=coverage \
-		$(C8) $(C8_FLAGS) $(NODE) $$test | $(TAP_REPORTER) || echo 'Tests failed.'; \
+		$(C8) $(c8_flags) $(NODE) $$test | $(TAP_REPORTER) || echo 'Tests failed.'; \
 	done
 endif