feat(policy): add imperative mood check (#108)

Signed-off-by: Andrew Rynhard <andrew@andrewrynhard.com>

.conform.yaml

@@ -4,18 +4,17 @@ policies:
     headerLength: 89
     dco: true
     gpg: true
-- type: conventionalCommit
-  spec:
-    types:
-    - chore
-    - docs
-    - perf
-    - refactor
-    - style
-    - test
-    scopes:
-    - policy
-    - '*'
+    imperative: true
+    conventional:
+      types:
+      - chore
+      - docs
+      - perf
+      - refactor
+      - style
+      - test
+      scopes:
+      - policy
 - type: license
   spec:
     includeSuffixes:

README.md

@@ -18,11 +18,12 @@
 
 Some of the policies included are:
 
-- **Commits**: Enforce basic commit policies including:
+- **Commits**: Enforce commit policies including:
   - Commit message header length
   - Developer Certificate of Origin
   - GPG signature
-- **Conventional Commits**: Enforce [conventional commits](https://www.conventionalcommits.org) for all commit messages.
+  - [Conventional Commits](https://www.conventionalcommits.org)
+  - Imperative verb
 - **License Headers**: Enforce license headers on source code files.
 
 ## Getting Started
@@ -36,12 +37,12 @@ policies:
     headerLength: 89
     dco: true
     gpg: true
-- type: conventionalCommit
-  spec:
-    types:
-      - "type"
-    scopes:
-      - "scope"
+    imperative: true
+    conventional:
+      types:
+        - "type"
+      scopes:
+        - "scope"
 - type: license
   spec:
     includeSuffixes:

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/kevinburke/ssh_config v0.0.0-20170525151105-fa48d7ff1cfb // indirect
+	github.com/kljensen/snowball v0.6.0
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/magiconair/properties v1.7.2 // indirect
 	github.com/mitchellh/go-homedir v0.0.0-20161203194507-b8bc1bf76747

go.sum

@@ -20,6 +20,8 @@ github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOl
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 github.com/kevinburke/ssh_config v0.0.0-20170525151105-fa48d7ff1cfb h1:4qB7kGgjot2tlCOW66sJ+ai5tv81oIDM9t6cvyFTKLM=
 github.com/kevinburke/ssh_config v0.0.0-20170525151105-fa48d7ff1cfb/go.mod h1:CT57kijsi8u/K/BOFA39wgDQJ9CxiF4nAY/ojJ6r6mM=
+github.com/kljensen/snowball v0.6.0 h1:6DZLCcZeL0cLfodx+Md4/OLC6b/bfurWUOUGs1ydfOU=
+github.com/kljensen/snowball v0.6.0/go.mod h1:27N7E8fVU5H68RlUmnWwZCfxgt4POBJfENGMvNRhldw=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=

internal/enforcer/enforcer.go

@@ -12,7 +12,6 @@ import (
 
 	"github.com/autonomy/conform/internal/policy"
 	"github.com/autonomy/conform/internal/policy/commit"
-	"github.com/autonomy/conform/internal/policy/conventionalcommit"
 	"github.com/autonomy/conform/internal/policy/license"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
@@ -34,9 +33,8 @@ type PolicyDeclaration struct {
 
 // policyMap defines the set of policies allowed within Conform.
 var policyMap = map[string]policy.Policy{
-	"commit":             &commit.Commit{},
-	"conventionalCommit": &conventionalcommit.Conventional{},
-	"license":            &license.License{},
+	"commit":  &commit.Commit{},
+	"license": &license.License{},
 	// "version":    &version.Version{},
 }
 

internal/policy/commit/blacklist.go

@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package commit
+
+// BlackList is the set of black listed imperative verbs.
+var BlackList = []string{
+	"a",
+	"an",
+	"the",
+	"action",
+	"always",
+	"api",
+	"base",
+	"basic",
+	"business",
+	"calculation",
+	"callback",
+	"collection",
+	"common",
+	"constructor",
+	"convenience",
+	"convenient",
+	"current",
+	"currently",
+	"custom",
+	"data",
+	"data",
+	"default",
+	"deprecated",
+	"description",
+	"dict",
+	"dictionary",
+	"does",
+	"dummy",
+	"example",
+	"factory",
+	"false",
+	"final",
+	"formula",
+	"function",
+	"generic",
+	"handler",
+	"handler",
+	"helper",
+	"here",
+	"hook",
+	"implementation",
+	"importantly",
+	"internal",
+	"it",
+	"main",
+	"method",
+	"module",
+	"new",
+	"number",
+	"optional",
+	"package",
+	"placeholder",
+	"reference",
+	"result",
+	"same",
+	"schema",
+	"setup",
+	"should",
+	"simple",
+	"some",
+	"special",
+	"sql",
+	"standard",
+	"static",
+	"string",
+	"subclasses",
+	"that",
+	"these",
+	"this",
+	"true",
+	"unique",
+	"unit",
+	"utility",
+	"what",
+	"wrapper",
+}

internal/policy/commit/commit.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/autonomy/conform/internal/git"
 	"github.com/autonomy/conform/internal/policy"
+	"github.com/kljensen/snowball"
 	"github.com/pkg/errors"
 )
 
@@ -23,6 +24,18 @@ type Commit struct {
 	DCO bool `mapstructure:"dco"`
 	// GPG enables the GPG signature check.
 	GPG bool `mapstructure:"gpg"`
+	// Imperative enforces the use of imperative verbs as the first word of a
+	// commit message.
+	Imperative bool `mapstructure:"imperative"`
+	// Conventional is the user specified settings for conventional commits.
+	Conventional *Conventional `mapstructure:"conventional"`
+}
+
+// Conventional implements the policy.Policy interface and enforces commit
+// messages to conform the Conventional Commit standard.
+type Conventional struct {
+	Types  []string `mapstructure:"types"`
+	Scopes []string `mapstructure:"scopes"`
 }
 
 // MaxNumberOfCommitCharacters is the default maximium number of characters
@@ -32,7 +45,26 @@ var MaxNumberOfCommitCharacters = 89
 // DCORegex is the regular expression used for Developer Certificate of Origin.
 var DCORegex = regexp.MustCompile(`^Signed-off-by: ([^<]+) <([^<>@]+@[^<>]+)>$`)
 
+// FirstWordRegex is theregular expression used to find the first word in a
+// commit.
+var FirstWordRegex = regexp.MustCompile(`^\s*([a-zA-Z0-9]+)`)
+
+// HeaderRegex is the regular expression used for Conventional Commits
+// 1.0.0-beta.1.
+var HeaderRegex = regexp.MustCompile(`^(\w*)(\(([^)]+)\))?:\s{1}(.*)($|\n{2})`)
+
+const (
+	// TypeFeat is a commit of the type fix patches a bug in your codebase
+	// (this correlates with PATCH in semantic versioning).
+	TypeFeat = "feat"
+
+	// TypeFix is a commit of the type feat introduces a new feature to the
+	// codebase (this correlates with MINOR in semantic versioning).
+	TypeFix = "fix"
+)
+
 // Compliance implements the policy.Policy.Compliance function.
+// nolint: gocyclo
 func (c *Commit) Compliance(options *policy.Options) (report policy.Report) {
 	var err error
 
@@ -72,6 +104,25 @@ func (c *Commit) Compliance(options *policy.Options) (report policy.Report) {
 		ValidateGPGSign(&report, g)
 	}
 
+	word := firstWord(msg)
+
+	if c.Conventional != nil {
+		groups := parseHeader(msg)
+		if len(groups) != 6 {
+			report.Errors = append(report.Errors, errors.Errorf("Invalid conventional commits format: %s", msg))
+			return
+		}
+		word = firstWord(groups[4])
+
+		ValidateType(&report, groups, c.Conventional.Types)
+		ValidateScope(&report, groups, c.Conventional.Scopes)
+		ValidateDescription(&report, groups)
+	}
+
+	if c.Imperative {
+		ValidateImperative(&report, word)
+	}
+
 	return report
 }
 
@@ -105,3 +156,73 @@ func ValidateGPGSign(report *policy.Report, g *git.Git) {
 		report.Errors = append(report.Errors, errors.Errorf("Commit does not have a GPG signature"))
 	}
 }
+
+// ValidateImperative checks the commit message for a GPG signature.
+func ValidateImperative(report *policy.Report, word string) {
+	word = strings.ToLower(word)
+	for _, good := range WhiteList {
+		stemmed, err := snowball.Stem(good, "english", true)
+		if err != nil {
+			report.Errors = append(report.Errors, errors.Errorf("Error checking for imperative mood: %v", err))
+		}
+		if word == stemmed {
+			return
+		}
+	}
+	for _, bad := range BlackList {
+		if word == bad {
+			report.Errors = append(report.Errors, errors.Errorf("Use of blacklisted imperative verb: %s", word))
+			return
+		}
+	}
+	report.Errors = append(report.Errors, errors.Errorf("Commit does not have imperative mood"))
+}
+
+// ValidateType returns the commit type.
+func ValidateType(report *policy.Report, groups []string, types []string) {
+	types = append(types, TypeFeat, TypeFix)
+	for _, t := range types {
+		if t == groups[1] {
+			return
+		}
+	}
+	report.Errors = append(report.Errors, errors.Errorf("Invalid type: %s, allowed types are: %v", groups[1], types))
+}
+
+// ValidateScope returns the commit scope.
+func ValidateScope(report *policy.Report, groups []string, scopes []string) {
+	// Scope is optional.
+	if groups[3] == "" {
+		return
+	}
+	for _, scope := range scopes {
+		if scope == groups[3] {
+			return
+		}
+	}
+	report.Errors = append(report.Errors, errors.Errorf("Invalid scope: %s, allowed scopes are: %v", groups[3], scopes))
+}
+
+// ValidateDescription returns the commit description.
+func ValidateDescription(report *policy.Report, groups []string) {
+	if len(groups[4]) <= 72 && len(groups[4]) != 0 {
+		return
+	}
+	report.Errors = append(report.Errors, errors.Errorf("Invalid description: %s", groups[4]))
+}
+
+func firstWord(msg string) string {
+	header := strings.Split(strings.TrimPrefix(msg, "\n"), "\n")[0]
+	groups := FirstWordRegex.FindStringSubmatch(header)
+	return groups[0]
+}
+
+func parseHeader(msg string) []string {
+	// To circumvent any policy violation due to the leading \n that GitHub
+	// prefixes to the commit message on a squash merge, we remove it from the
+	// message.
+	header := strings.Split(strings.TrimPrefix(msg, "\n"), "\n")[0]
+	groups := HeaderRegex.FindStringSubmatch(header)
+
+	return groups
+}

internal/policy/conventionalcommit/conventionalcommit_test.go → internal/policy/commit/commit_test.go

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-package conventionalcommit
+package commit
 
 import (
 	"io/ioutil"
@@ -76,9 +76,12 @@ func TestInvalidConventionalCommitPolicy(t *testing.T) {
 }
 
 func runCompliance() (*policy.Report, error) {
-	c := &Conventional{}
-	c.Types = []string{"type"}
-	c.Scopes = []string{"scope"}
+	c := &Commit{
+		Conventional: &Conventional{
+			Types:  []string{"type"},
+			Scopes: []string{"scope"},
+		},
+	}
 
 	report := c.Compliance(&policy.Options{})