Adds pre-commit hook, hook config script, and a README

The pre-commit hook will automatically gofmt code in place, warning you
about any changes. It will also fail to commit if either golint or go
vet fails.

Author: BrianBland

project/hooks/README.md

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+Git Hooks
+=========
+
+To enforce valid and properly-formatted code, there is CI in place which runs `gofmt`, `golint`, and `go vet` against code in the repository.
+
+As an aid to prevent committing invalid code in the first place, a git pre-commit hook has been added to the repository, found in [pre-commit](./pre-commit). As it is impossible to automatically add linked hooks to a git repository, this hook should be linked into your `.git/hooks/pre-commit`, which can be done by running the `configure-hooks.sh` script in this directory. This script is the preferred method of configuring hooks, as it will be updated as more are added.

project/hooks/configure-hooks.sh

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+#!/bin/sh
+
+cd $(dirname $0)
+
+REPO_ROOT=$(git rev-parse --show-toplevel)
+RESOLVE_REPO_ROOT_STATUS=$?
+if [ "$RESOLVE_REPO_ROOT_STATUS" -ne "0" ]; then
+	echo -e "Unable to resolve repository root. Error:\n$REPO_ROOT" > /dev/stderr
+	exit $RESOLVE_REPO_ROOT_STATUS
+fi
+
+set -e
+set -x
+
+# Just in case the directory doesn't exist
+mkdir -p $REPO_ROOT/.git/hooks
+
+ln -f -s $(pwd)/pre-commit $REPO_ROOT/.git/hooks/pre-commit

project/hooks/pre-commit

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+#!/bin/sh
+
+REPO_ROOT=$(git rev-parse --show-toplevel)
+RESOLVE_REPO_ROOT_STATUS=$?
+if [ "$RESOLVE_REPO_ROOT_STATUS" -ne "0" ]; then
+	printf "Unable to resolve repository root. Error:\n%s\n" "$RESOLVE_REPO_ROOT_STATUS" > /dev/stderr
+	exit $RESOLVE_REPO_ROOT_STATUS
+fi
+
+cd $REPO_ROOT
+
+GOFMT_CHANGES=$(gofmt -s -l -w . 2>&1)
+if [ -n "$GOFMT_CHANGES" ]; then
+	printf "gofmt corrected the following files:\n%s\n" "$GOFMT_CHANGES" > /dev/stderr
+fi
+
+GOLINT_ERRORS=$(golint ./... 2>&1)
+if [ -n "$GOLINT_ERRORS" ]; then
+	printf "golint failed with the following errors:\n%s\n" "$GOLINT_ERRORS" > /dev/stderr
+	exit 1
+fi
+
+GOVET_ERRORS=$(go vet ./... 2>&1)
+GOVET_STATUS=$?
+if [ "$GOVET_STATUS" -ne "0" ]; then
+	printf "govet failed with the following errors:\n%s\n" "$GOVET_ERRORS" > /dev/stderr
+	exit $GOVET_STATUS
+fi