ARROW-11101: [Rust] rewrite pre-commit hook

Currently,  the client side git pre-commit hook checks and runs `cargo fmt` with stable version, but the CI check may fail in nightly version occasionally even if the code has been formatted with stable.

It seems that, this problem can be resolved by: running `cargo +nighty fmt` before  `cargo +stable fmt`. Thus `pre-commit.sh` should be updated in this way.

In this PR:

1. only check staged *.rs files and exit if no changes
2. cargo clippy is moved before cargo fmt
3. run `cargo +nighty fmt` before  cargo +stable fmt
4. show more concise tip messages
5. abort the commit if there are files changed by `cargo fmt`

Closes apache#9072 from mqy/rewrite-pre-commit-hook

Authored-by: mqy <meng.qingyou@gmail.com>
Signed-off-by: Andrew Lamb <andrew@nerdnetworks.org>

rust/pre-commit.sh

@@ -21,9 +21,9 @@
 #
 # Soft link it as git hook under top dir of apache arrow git repository:
 # $ ln -s  ../../rust/pre-commit.sh .git/hooks/pre-commit
-
-# NOTE: colorized output may not work as expected.
-#       I've seen the difference between /bin/sh and GUN bash 5 on macOS.
+#
+# This file be run directly:
+# $ ./pre-commit.sh
 
 function RED() {
 	echo "\033[0;31m$@\033[0m"
@@ -37,50 +37,52 @@ function BYELLOW() {
 	echo "\033[1;33m$@\033[0m"
 }
 
-MSG="git pre-commit hook"
 RUST_DIR="rust"
-CARGO_FMT="cargo +stable fmt --all"
-CARGO_CLIPPY="cargo clippy"
-
-NUM_CHANGES=$(git diff --cached --name-only "${RUST_DIR}" |
-	grep -e ".*/*.rs$" -o -e "^rustfmt.toml$" -o -e "^rust-toolchain$" |
-	awk '{print $1}' |
-	wc -l)
 
-if [ ${NUM_CHANGES} -eq 0 ]; then
-	echo -e "$(GREEN INFO) ${MSG}: no changes in: *rs, rustfmt.toml, rust-toolchain, skip fmt/clippy"
-	#exit 0
+# env GIT_DIR is set by git when run a pre-commit hook.
+if [ -z "${GIT_DIR}" ]; then
+	GIT_DIR=$(git rev-parse --show-toplevel)
 fi
 
-cd ${RUST_DIR}
+cd ${GIT_DIR}/${RUST_DIR}
 
-# 1. Abort on cargo fmt error.
-
-echo -e "$(GREEN INFO) ${MSG}: cargo fmt checking ..."
+NUM_CHANGES=$(git diff --cached --name-only . |
+	grep -e ".*/*.rs$" |
+	awk '{print $1}' |
+	wc -l)
 
-$CARGO_FMT -q -- --check 2>/dev/null
-if [ $? -eq 0 ]; then
-	echo -e "$(GREEN INFO) ${MSG}: $(GREEN cargo fmt check passed)"
-else
-	echo -e "$(GREEN INFO) ${MSG}: cargo fmt formatting ..."
-	$CARGO_FMT
-	echo
-	echo -e "$(BYELLOW WARN) ${MSG}: cargo fmt $(BYELLOW fixed some files)"
+if [ ${NUM_CHANGES} -eq 0 ]; then
+	echo -e "$(GREEN INFO): no staged changes in *.rs, $(GREEN skip cargo fmt/clippy)"
+	exit 0
 fi
 
-# 2. Warn on cargo clippy errors/warnings.
+# 1. cargo clippy
 
-echo
-echo "===================================================="
-echo
-echo -e "$(GREEN INFO) ${MSG}: cargo clippy ..."
-echo
+echo -e "$(GREEN INFO): cargo clippy ..."
 
-# Cargo clippy always return exit code 0, and tee doesnt work.
+# Cargo clippy always return exit code 0, and `tee` doesn't work.
 # So let's just run cargo clippy.
-$CARGO_CLIPPY
-echo
-echo -e "$(BYELLOW WARN) ${MSG}: please try fix $(BYELLOW clippy issues) if any"
-echo
+cargo clippy
+echo -e "$(GREEN INFO): cargo clippy done"
+
+# 2. cargo fmt: format with nightly and stable.
+
+CHANGED_BY_CARGO_FMT=false
+echo -e "$(GREEN INFO): cargo fmt with nightly and stable ..."
+
+for version in nightly stable; do
+	CMD="cargo +${version} fmt"
+	${CMD} --all -q -- --check 2>/dev/null
+	if [ $? -ne 0 ]; then
+		${CMD} --all
+		echo -e "$(BYELLOW WARN): ${CMD} changed some files"
+		CHANGED_BY_CARGO_FMT=true
+	fi
+done
+
+if ${CHANGED_BY_CARGO_FMT}; then
+	echo -e "$(RED FAIL): git commit $(RED ABORTED), please have a look and run git add/commit again"
+	exit 1
+fi
 
 exit 0