Adds pre-commit to improve quality (#184)

* Adds initial hooks

* Work on tool install

* Actually implements the hooks
Does the actual hook implementation but doesn't run them.

* --no-verify

improve readme with --no-verify tip

* RUNS commits hooks

* Revert "RUNS commits hooks"

This reverts commit 30100f1.

* Removes tomlv from tools

* Updates RM instructions

* Update README.md

Co-authored-by: Daniel <[email protected]>

.pre-commit-config.yaml

@@ -0,0 +1,36 @@
+# install pre-commit `brew install pre-commit`
+# install hooks to git `pre-commit install`
+# update the hooks `pre-commit autoupdate`
+# to run the hooks `pre-commit run --all-files`
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.3.0
+    hooks:
+      - id: check-merge-conflict
+      - id: check-added-large-files
+      - id: check-yaml
+      - id: end-of-file-fixer
+      - id: trailing-whitespace
+  - repo: local
+    hooks:
+      - id: install-tools
+        name: "install tools"
+        entry: "./scripts/install_tools.sh"
+        language: script
+        description: "Installs tools needed for go static analysis hooks"
+      - id: go-vet
+        name: "go vet"
+        entry: "./scripts/go_vet.sh"
+        language: script
+        description: "Installs tools needed for go static analysis hooks"
+
+  - repo: https://github.com/dnephin/pre-commit-golang
+    rev: master
+    hooks:
+      - id: go-fmt
+      - id: go-imports
+      - id: go-cyclo
+        args: [-over=15]
+      - id: go-mod-tidy
+      - id: go-build
+      - id: go-critic

README.md

@@ -77,6 +77,25 @@ gofmt -w -s -e .
 go vet ./...
 ```
 
+Some useful tools are included in the repository using [pre-commit](https://pre-commit.com/hooks.html). pre-commit lets you run developer tools either on every git commit, or manually with `pre-commit run --all-files`. See the [config](./.pre-commit-config.yaml) for details. In this repo the hooks are not installed to git, as that can be cumbersome, but it is still possible to benefit from them.
+
+```bash
+## Prerequisites
+
+# pre-commit
+brew install pre-commit
+# goimports (https://pkg.go.dev/golang.org/x/tools/cmd/goimports)
+go install golang.org/x/tools/cmd/goimports@latest
+# gocyclo (https://github.com/fzipp/gocyclo)
+go install github.com/fzipp/gocyclo/cmd/gocyclo@latest
+# go-critic https://github.com/go-critic/go-critic
+go install github.com/go-critic/go-critic/cmd/gocritic@latest
+
+## Run the tools
+
+pre-commit run --all-files
+```
+
 **Debugging**
 
 If using VSCode, see [vscode-go/wiki/debugging](https://github.com/golang/vscode-go/wiki/debugging) to debug unit tests or go binaries.

scripts/go_vet.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -e
+pkg=$(go list ./...)
+for dir in $(echo $@|xargs -n1 dirname|sort -u); do
+  go vet $pkg/$dir
+done

scripts/install_tools.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -e -o pipefail
+
+if ! command -v gocyclo &> /dev/null ; then
+    echo "gocyclo not installed or available in the PATH, installing" >&2
+    go install github.com/fzipp/gocyclo/cmd/gocyclo@latest;
+fi
+
+if ! command -v gocritic &> /dev/null ; then
+    echo "gocritic not installed or available in the PATH, installing" >&2
+    go install github.com/go-critic/go-critic/cmd/gocritic@latest;
+fi
+
+if ! command -v goimports &> /dev/null ; then
+    echo "goimports not installed or available in the PATH, installing" >&2
+    go install golang.org/x/tools/cmd/goimports@latest;
+fi
+
+exit 0