message_regexp: regular expression rule for messages

Fixes: #30

now you can add a regular expression to the rules to be run
i.e. `git-validation -run "dco,message_regexp='^JIRA-[0-9]+ [A-Z].*$'"`

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

README.md

@@ -30,7 +30,9 @@ Usage of git-validation:
 The entire default rule set is run by default:
 ```console
 vbatts@valse ~/src/vb/git-validation (master) $ git-validation -list-rules
+"dangling-whitespace" -- checking the presence of dangling whitespaces on line endings
 "DCO" -- makes sure the commits are signed
+"message_regexp" -- checks the commit message for a user provided regular expression
 "short-subject" -- commit subjects are strictly less than 90 (github ellipsis length)
 ```
 
@@ -92,6 +94,7 @@ vbatts@valse ~/src/vb/git-validation (master) $ GIT_CHECK_EXCLUDE="./vendor" git
 ```
 using the `GIT_CHECK_EXCLUDE` environment variable
 
+
 ## Rules
 
 Default rules are added by registering them to the `validate` package.

main.go

@@ -9,6 +9,7 @@ import (
 
 	_ "github.com/vbatts/git-validation/rules/danglingwhitespace"
 	_ "github.com/vbatts/git-validation/rules/dco"
+	_ "github.com/vbatts/git-validation/rules/messageregexp"
 	_ "github.com/vbatts/git-validation/rules/shortsubject"
 	"github.com/vbatts/git-validation/validate"
 )
@@ -47,10 +48,20 @@ func main() {
 		return
 	}
 
-	// reduce the set being run
-	rules := validate.RegisteredRules
+	// rules to be used
+	var rules []validate.Rule
+	for _, r := range validate.RegisteredRules {
+		// only those that are Default
+		if r.Default {
+			rules = append(rules, r)
+		}
+	}
+	// or reduce the set being run to what the user provided
 	if *flRun != "" {
-		rules = validate.FilterRules(rules, validate.SanitizeFilters(*flRun))
+		rules = validate.FilterRules(validate.RegisteredRules, validate.SanitizeFilters(*flRun))
+	}
+	if os.Getenv("DEBUG") != "" {
+		log.Printf("%#v", rules) // XXX maybe reduce this list
 	}
 
 	var commitRange = *flCommitRange

rules/danglingwhitespace/rule.go

@@ -12,6 +12,7 @@ var (
 		Name:        "dangling-whitespace",
 		Description: "checking the presence of dangling whitespaces on line endings",
 		Run:         ValidateDanglingWhitespace,
+		Default:     true,
 	}
 )
 
@@ -20,7 +21,7 @@ func init() {
 }
 
 // ValidateDanglingWhitespace runs Git's check to look for whitespace errors.
-func ValidateDanglingWhitespace(c git.CommitEntry) (vr validate.Result) {
+func ValidateDanglingWhitespace(r validate.Rule, c git.CommitEntry) (vr validate.Result) {
 	vr.CommitEntry = c
 	vr.Msg = "commit does not have any whitespace errors"
 	vr.Pass = true

rules/dco/dco.go

@@ -20,11 +20,12 @@ var (
 		Name:        "DCO",
 		Description: "makes sure the commits are signed",
 		Run:         ValidateDCO,
+		Default:     true,
 	}
 )
 
 // ValidateDCO checks that the commit has been signed off, per the DCO process
-func ValidateDCO(c git.CommitEntry) (vr validate.Result) {
+func ValidateDCO(r validate.Rule, c git.CommitEntry) (vr validate.Result) {
 	vr.CommitEntry = c
 	if len(strings.Split(c["parent"], " ")) > 1 {
 		vr.Pass = true

rules/messageregexp/rule.go

@@ -0,0 +1,61 @@
+package messageregexp
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/vbatts/git-validation/git"
+	"github.com/vbatts/git-validation/validate"
+)
+
+func init() {
+	validate.RegisterRule(RegexpRule)
+}
+
+var (
+	// RegexpRule for validating a user provided regex on the commit messages
+	RegexpRule = validate.Rule{
+		Name:        "message_regexp",
+		Description: "checks the commit message for a user provided regular expression",
+		Run:         ValidateMessageRegexp,
+		Default:     false, // only for users specifically calling it through -run ...
+	}
+)
+
+// ValidateMessageRegexp is the message regex func to run
+func ValidateMessageRegexp(r validate.Rule, c git.CommitEntry) (vr validate.Result) {
+	if r.Value == "" {
+		vr.Pass = true
+		vr.Msg = "noop: message_regexp value is blank"
+		return vr
+	}
+
+	re := regexp.MustCompile(r.Value)
+	vr.CommitEntry = c
+	if len(strings.Split(c["parent"], " ")) > 1 {
+		vr.Pass = true
+		vr.Msg = "merge commits are not checked for message_regexp"
+		return vr
+	}
+
+	hasValid := false
+	for _, line := range strings.Split(c["subject"], "\n") {
+		if re.MatchString(line) {
+			hasValid = true
+		}
+	}
+	for _, line := range strings.Split(c["body"], "\n") {
+		if re.MatchString(line) {
+			hasValid = true
+		}
+	}
+	if !hasValid {
+		vr.Pass = false
+		vr.Msg = fmt.Sprintf("commit message does not match %q", r.Value)
+	} else {
+		vr.Pass = true
+		vr.Msg = fmt.Sprintf("commit message matches %q", r.Value)
+	}
+	return vr
+}

rules/shortsubject/shortsubject.go

@@ -11,6 +11,7 @@ var (
 		Name:        "short-subject",
 		Description: "commit subjects are strictly less than 90 (github ellipsis length)",
 		Run:         ValidateShortSubject,
+		Default:     true,
 	}
 )
 
@@ -20,7 +21,7 @@ func init() {
 
 // ValidateShortSubject checks that the commit's subject is strictly less than
 // 90 characters (preferably not more than 72 chars).
-func ValidateShortSubject(c git.CommitEntry) (vr validate.Result) {
+func ValidateShortSubject(r validate.Rule, c git.CommitEntry) (vr validate.Result) {
 	if len(c["subject"]) >= 90 {
 		vr.Pass = false
 		vr.Msg = "commit subject exceeds 90 characters"

validate/rules.go

@@ -9,7 +9,7 @@ import (
 )
 
 var (
-	// RegisteredRules are the standard validation to perform on git commits
+	// RegisteredRules are the avaible validation to perform on git commits
 	RegisteredRules  = []Rule{}
 	registerRuleLock = sync.Mutex{}
 )
@@ -26,14 +26,15 @@ type Rule struct {
 	Name        string // short name for reference in in the `-run=...` flag
 	Value       string // value to configure for the rule (i.e. a regexp to check for in the commit message)
 	Description string // longer Description for readability
-	Run         func(git.CommitEntry) Result
+	Run         func(Rule, git.CommitEntry) Result
+	Default     bool // whether the registered rule is run by default
 }
 
 // Commit processes the given rules on the provided commit, and returns the result set.
 func Commit(c git.CommitEntry, rules []Rule) Results {
 	results := Results{}
 	for _, r := range rules {
-		results = append(results, r.Run(c))
+		results = append(results, r.Run(r, c))
 	}
 	return results
 }

validate/rules_test.go

@@ -46,7 +46,7 @@ func TestSliceHelpers(t *testing.T) {
 	for i := range set {
 		got := StringsSliceEqual(set[i].A, set[i].B)
 		if got != set[i].Equal {
-			t.Errorf("expected %d A and B comparison to be %q, but got %q", i, set[i].Equal, got)
+			t.Errorf("expected %d A and B comparison to be %t, but got %t", i, set[i].Equal, got)
 		}
 	}
 }