test: Add tools to generate test coverage information

This patch adds some tooling and scripts to generate test coverage
information.

Unfortunately, this involves some hacks as Go does not have support for
generating coverage-enabled binaries, or merging coverage reports; but
overall it's not very intrusive.

test/cover.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+# Runs tests (both go and integration) in coverage-generation mode.
+# Generates an HTML report with the results.
+#
+# The .coverage directory is used to store the data, it will be erased and
+# recreated on each run.
+#
+# This is not very tidy, and relies on some hacky tricks (see
+# coverage_test.go), but works for now.
+
+set -e
+. $(dirname ${0})/util/lib.sh
+
+init
+
+cd "${TBASE}/.."
+
+# Recreate the coverage output directory, to avoid including stale results
+# from previous runs.
+rm -rf .coverage
+mkdir -p .coverage
+export COVER_DIR="$PWD/.coverage"
+
+# Normal go tests.
+go test -tags coverage \
+	-covermode=count \
+	-coverprofile="$COVER_DIR/pkg-tests.out"\
+	-coverpkg=./... ./...
+
+# Integration tests.
+# Will run in coverage mode due to $COVER_DIR being set.
+setsid -w ./test/run.sh
+
+# Merge all coverage output into a single file.
+# Ignore protocol buffer-generated files, as they are not relevant.
+go run "${UTILDIR}/gocovcat.go" .coverage/*.out \
+	| grep -v ".pb.go:" \
+	> .coverage/all.out
+
+# Generate reports based on the merged output.
+go tool cover -func="$COVER_DIR/all.out" | sort -k 3 -n > "$COVER_DIR/func.txt"
+go tool cover -html="$COVER_DIR/all.out" -o "$COVER_DIR/chasquid.html"
+
+echo
+echo "Coverage report can be found in:"
+echo file://$COVER_DIR/chasquid.html
+