feat: script to produce coverage report for wallet (#3938)

Description
---
This PR adds a script that will use the LLVM profiler and grcov to produce a coverage report of the wallet crate.

.gitignore

@@ -50,3 +50,7 @@ buildtools/Output/
 # any specific "assets" folders should be gitignored
 # closer to where they live
 #assets/
+
+# Ignore coverage profiling artifacts
+*.profraw
+/report/

scripts/code_coverage_wallet.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+set -e
+
+REPORT_DIR="report/"
+CRATE_DIR="../base_layer/wallet"
+RELATIVE_TARGET_DIR="../../target/debug"
+
+echo "Check if latest llvm-tools are installed:"
+rustup component add llvm-tools-preview
+
+echo "Check if grcov installed:"
+if [ "$(command -v grcov)" ]
+then
+    echo "    + Already installed"
+else
+    echo "    + Installing.."
+    cargo install grcov
+fi
+
+export LLVM_PROFILE_FILE="coverage_data-%p-%m.profraw"
+export RUSTFLAGS="-Zinstrument-coverage"
+
+echo "Running Wallet tests to produce coverage profiling data:"
+cd $CRATE_DIR
+# We force the tests to use a single thread. Something about the profiling breaks the Sqlite connection pool even though every test
+# with a db uses its own unique pool connection to its own unique file  ¯\_(ツ)_/¯
+cargo test -- --test-threads=1
+
+echo "Clear Report directories:"
+if [ -d "$report_dir" ]; then
+    rm -rf $report_dir
+    echo "    + Report directory removed"
+else
+    echo "    + Report directory already cleared"
+fi
+
+
+echo "Generating coverage report:"
+grcov . -s . --binary-path $RELATIVE_TARGET_DIR -t html --branch --ignore-not-existing -o $REPORT_DIR
+
+CUR_DIR=$(pwd)
+echo "Coverage report can be found in $CUR_DIR/$REPORT_DIR"