From 0b57cdd736e7ce5cbcebea29c9bca7a3c841aff8 Mon Sep 17 00:00:00 2001
From: Pratyush Mishra <pratyushmishra@berkeley.edu>
Date: Wed, 4 Mar 2020 16:05:57 -0800
Subject: [PATCH] Add a pre-commit hook for rustfmt (#102)

* add a pre-commit hook for rustfmt

* make printing sccache stats optional

* fixup! add a pre-commit hook for rustfmt
---
 .hooks/pre-commit       | 36 ++++++++++++++++++++++++++++++++++++
 scripts/install-hook.sh |  9 +++++++++
 2 files changed, 45 insertions(+)
 create mode 100755 .hooks/pre-commit
 create mode 100755 scripts/install-hook.sh

diff --git a/.hooks/pre-commit b/.hooks/pre-commit
new file mode 100755
index 0000000..f3a3b0d
--- /dev/null
+++ b/.hooks/pre-commit
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+rustfmt --version &>/dev/null
+if [ $? != 0 ]; then
+        printf "[pre_commit] \033[0;31merror\033[0m: \"rustfmt\" not available. \n"
+        printf "[pre_commit] \033[0;31merror\033[0m: rustfmt can be installed via - \n"
+        printf "[pre_commit] $ rustup component add rustfmt-preview \n"
+        exit 1
+fi
+
+problem_files=()
+
+# collect ill-formatted files
+for file in $(git diff --name-only --cached); do
+        if [ ${file: -3} == ".rs" ]; then
+                rustfmt --check $file &>/dev/null
+                if [ $? != 0 ]; then
+                        problem_files+=($file)
+                fi
+        fi
+done
+
+if [ ${#problem_files[@]} == 0 ]; then
+  # done
+  printf "[pre_commit] rustfmt \033[0;32mok\033[0m \n"
+else
+  # reformat the files that need it and re-stage them.
+  printf "[pre_commit] the following files were rustfmt'd before commit: \n"
+  for file in ${problem_files[@]}; do
+    rustfmt $file
+    git add $file
+    printf "\033[0;32m    $file\033[0m \n"
+  done
+fi
+
+exit 0
\ No newline at end of file
diff --git a/scripts/install-hook.sh b/scripts/install-hook.sh
new file mode 100755
index 0000000..eafcf81
--- /dev/null
+++ b/scripts/install-hook.sh
@@ -0,0 +1,9 @@
+#!/bin/env bash
+# This script will install the provided directory ../.hooks as the hook
+# directory for the present repo. See there for hooks, including a pre-commit
+# hook that runs rustfmt on files before a commit.
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+HOOKS_DIR="${DIR}/../.hooks"
+
+git config core.hooksPath "$HOOKS_DIR"