build-loop-rust.sh

#!/bin/sh

#
# A looping build script which builds when a file changes. Helpful when editing Rust 
# source code without a proper IDE or language server. This script uses cargo-watch if 
# it is available or Linux inotify if not.
#
# Dependencies: 
#   cargo-watch OR inotify-tools (Linux-only)
#   cargo-audit (optional)
#   cargo-outdated (optional)
#

COMMAND=${1:-test}

# Reset terminal
reset

# Some statistics
find src -name "*.rs" | xargs wc -l && sleep 1s && echo ""

# Update, show vulnerable crates and list outdated root crates
cargo update && echo ""
cargo help outdated &>/dev/null && cargo outdated -R && sleep 1s && echo ""
cargo help audit &>/dev/null && cargo audit && sleep 1s && echo ""

# Use cargo-watch if it is installed
if cargo watch --version &>/dev/null ; then
    # The initial build
    cargo $COMMAND $*
    
    # Build on demand
    cargo watch --postpone -cx $COMMAND $*
else
    # The initial build
    shift 2>/dev/null
    echo "Running cargo with subcommand '$COMMAND' $*"
    cargo $COMMAND $*

    # Build on demand
    while inotifywait -e modify --exclude target -r . &>/dev/null ; do
        sync
        clear
        cargo $COMMAND $*
    done
fi