Test coverage (#4596)

* update .gitignore

* add test-with-coverage.sh

* coverage gutters extension comment

* move lcov.info to target folder

---------

Co-authored-by: SleeplessOne1917 <28871516+SleeplessOne1917@users.noreply.github.com>

scripts/test-with-coverage.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -e
+
+CWD="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+
+cd $CWD/../
+
+PACKAGE="$1"
+echo "$PACKAGE"
+
+source scripts/start_dev_db.sh
+
+# tests are executed in working directory crates/api (or similar),
+# so to load the config we need to traverse to the repo root
+export LEMMY_CONFIG_LOCATION=../../config/config.hjson
+export RUST_BACKTRACE=1
+
+cargo install cargo-llvm-cov
+
+# Create lcov.info file, which is used by things like the Coverage Gutters extension for VS Code
+cargo llvm-cov --workspace --all-features --no-fail-fast --lcov --output-path target/lcov.info
+
+# Add this to do printlns: -- --nocapture
+
+pg_ctl stop --silent
+rm -rf $PGDATA