(#32) Support for commit-msg hook with msg-file flag (#37)

README.md

@@ -23,26 +23,53 @@ Flags:
   --subject-regex=".*"      Commit subject line must conform to this regular expression (default: ".*").
   --subject-len=2147483646  Commit subject line cannot exceed this length (default: math.MaxInt32 - 1).
   --body-regex=".*"         Commit message body must conform to this regular expression (default: ".*").
-  --since="1970-01-01"      A date in "yyyy-MM-dd" format starting from which commits will be analyzed (default: "1970-01-01")
+  --since="1970-01-01"      A date in "yyyy-MM-dd" format starting from which commits will be analyzed (default: "1970-01-01").
+  --msg-file=""             Only analyze the commit message found in this file (default: "").
 ```
 Additionally, it will look for configurations in a file `.gitlint` in the current directory if it exists. This file's format is just the same command line flags but each on a separate line. *Flags passed through the command line take precedence.*
 
-## Integrate to your CI
+### Lint your commit msg when committing
 
-Use the [`download-gitlint.sh`](https://raw.githubusercontent.com/llorllale/go-gitlint/master/download-gitlint.sh) script:
+Add a `commit-msg` hook to your Git repo:
 
-`curl -sfL https://raw.githubusercontent.com/llorllale/go-gitlint/master/download-gitlint.sh | sh -s 1.0.0`
+1. Create hook: `echo 'gitlint --msg-file=$1' > .git/hooks/commit-msg`
+2. Make it executable: `chmod +x .git/hooks/commit-msg`
 
-Specifying the version is optional; if you just want the latest, omit the `-s <version>` part.
+Now your commits will be validated after saving and closing the commit message in your text editor.
 
-In both cases the correct version for your platform will be downloaded and installed at `$GOPATH/bin`.
+### Integrate to your CI
+
+Use [`download-gitlint.sh`](https://raw.githubusercontent.com/llorllale/go-gitlint/master/download-gitlint.sh):
+
+1. `curl https://raw.githubusercontent.com/llorllale/go-gitlint/master/download-gitlint.sh > download-gitlint.sh`
+2. `chmod +x download-gitlint.sh`
+
+Usage:
+```
+$ ./download-gitlint.sh -h
+./download-gitlint.sh: download go binaries for llorllale/go-gitlint
+
+Usage: ./download-gitlint.sh [-b] bindir [-d] [tag]
+  -b sets bindir or installation directory, Defaults to ./bin
+  -d turns on debug logging
+   [tag] is a tag from
+   https://github.com/llorllale/go-gitlint/releases
+   If tag is missing, then the latest will be used.
+
+ Generated by godownloader
+  https://github.com/goreleaser/godownloader
+```
+
+### Exit codes
+
+`gitlint`'s exit code will equal the number of issues found with your commit(s).
 
 ## Motivation
 
 - [X] Validate format of commit message subject and body
 - [X] Lint commit msgs on varios development platforms (Windows, Linux, Mac)
 - [X] Configuration from file with cli args taking precedence
-- [ ] [`commit-msg`](https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks) hook to validate my commit's msg
+- [X] [`commit-msg`](https://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks) hook to validate my commit's msg
 - [X] Performance (because a slow pre-commit hook would render the git workflow unmanageable)
 - [X] My first Go project :)
 

cmd/go-gitlint/main.go

@@ -30,11 +30,12 @@ import (
 //  Figure out a way to remove these global variables. Whatever command line
 //  parser we choose should be able to auto-generate usage.
 var (
-	path          = kingpin.Flag("path", `Path to the git repo (default: ".").`).Default(".").String()                                                                         //nolint[gochecknoglobals]
-	subjectRegex  = kingpin.Flag("subject-regex", `Commit subject line must conform to this regular expression (default: ".*").`).Default(".*").String()                       //nolint[gochecknoglobals]
-	subjectLength = kingpin.Flag("subject-len", "Commit subject line cannot exceed this length (default: math.MaxInt32 - 1).").Default(strconv.Itoa(math.MaxInt32 - 1)).Int()  //nolint[gochecknoglobals]
-	bodyRegex     = kingpin.Flag("body-regex", `Commit message body must conform to this regular expression (default: ".*").`).Default(".*").String()                          //nolint[gochecknoglobals]
-	since         = kingpin.Flag("since", `A date in "yyyy-MM-dd" format starting from which commits will be analyzed (default: "1970-01-01")`).Default("1970-01-01").String() //nolint[gochecknoglobals]
+	path          = kingpin.Flag("path", `Path to the git repo (default: ".").`).Default(".").String()                                                                          //nolint[gochecknoglobals]
+	subjectRegex  = kingpin.Flag("subject-regex", `Commit subject line must conform to this regular expression (default: ".*").`).Default(".*").String()                        //nolint[gochecknoglobals]
+	subjectLength = kingpin.Flag("subject-len", "Commit subject line cannot exceed this length (default: math.MaxInt32 - 1).").Default(strconv.Itoa(math.MaxInt32 - 1)).Int()   //nolint[gochecknoglobals]
+	bodyRegex     = kingpin.Flag("body-regex", `Commit message body must conform to this regular expression (default: ".*").`).Default(".*").String()                           //nolint[gochecknoglobals]
+	since         = kingpin.Flag("since", `A date in "yyyy-MM-dd" format starting from which commits will be analyzed (default: "1970-01-01").`).Default("1970-01-01").String() //nolint[gochecknoglobals]
+	msgFile       = kingpin.Flag("msg-file", `Only analyze the commit message found in this file (default: "").`).Default("").String()                                          //nolint[gochecknoglobals]
 )
 
 func main() {
@@ -49,11 +50,23 @@ func main() {
 						issues.OfBodyRegex(*bodyRegex),
 						issues.OfSubjectLength(*subjectLength),
 					},
-					commits.Since(
-						*since,
-						commits.In(
-							repo.Filesystem(*path),
-						),
+					try(
+						len(*msgFile) > 0,
+						func() commits.Commits {
+							file, err := os.Open(*msgFile)
+							if err != nil {
+								panic(err)
+							}
+							return commits.MsgIn(file)
+						},
+						func() commits.Commits {
+							return commits.Since(
+								*since,
+								commits.In(
+									repo.Filesystem(*path),
+								),
+							)
+						},
 					),
 				),
 			)(),
@@ -75,3 +88,10 @@ func configure() {
 		panic(err)
 	}
 }
+
+func try(cond bool, actual, dflt func() commits.Commits) commits.Commits {
+	if cond {
+		return actual()
+	}
+	return dflt()
+}

internal/commits/commits.go

@@ -15,6 +15,8 @@
 package commits
 
 import (
+	"io"
+	"io/ioutil"
 	"strings"
 	"time"
 
@@ -110,3 +112,19 @@ func Since(t string, cmts Commits) Commits {
 		return filtered
 	}
 }
+
+// MsgIn returns a single fake commit with the message read from this reader.
+// This fake commit will have a fake hash and its timestamp will be time.Now().
+func MsgIn(reader io.Reader) Commits {
+	return func() []*Commit {
+		b, err := ioutil.ReadAll(reader)
+		if err != nil {
+			panic(err)
+		}
+		return []*Commit{{
+			Hash:    "fakehsh",
+			Message: string(b),
+			Date:    time.Now(),
+		}}
+	}
+}

internal/commits/commits_test.go

@@ -98,6 +98,14 @@ func TestSince(t *testing.T) {
 	assert.Contains(t, commits, &Commit{Date: after})
 }
 
+func TestMsgIn(t *testing.T) {
+	const message = "test subject\n\ntest body"
+	commits := MsgIn(strings.NewReader(message))()
+	assert.Len(t, commits, 1)
+	assert.Equal(t, "test subject", commits[0].Subject())
+	assert.Equal(t, "test body", commits[0].Body())
+}
+
 // A git repo initialized and with one commit per each of the messages provided.
 // This repo is created in a temporary directory; use the cleanup function
 // to delete it afterwards.