feat(rules): add body-full-stop rule

@commitlint/rules/src/body-full-stop.test.ts

@@ -0,0 +1,50 @@
+import parse from '@commitlint/parse';
+import {bodyFullStop} from './body-full-stop';
+
+const messages = {
+	empty: 'test:\n',
+	with: `test: subject\n\nbody.`,
+	without: `test: subject\n\nbody`,
+};
+
+const parsed = {
+	empty: parse(messages.empty),
+	with: parse(messages.with),
+	without: parse(messages.without),
+};
+
+test('empty against "always" should succeed', async () => {
+	const [actual] = bodyFullStop(await parsed.empty, 'always', '.');
+	const expected = true;
+	expect(actual).toEqual(expected);
+});
+
+test('empty against "never ." should succeed', async () => {
+	const [actual] = bodyFullStop(await parsed.empty, 'never', '.');
+	const expected = true;
+	expect(actual).toEqual(expected);
+});
+
+test('with against "always ." should succeed', async () => {
+	const [actual] = bodyFullStop(await parsed.with, 'always', '.');
+	const expected = true;
+	expect(actual).toEqual(expected);
+});
+
+test('with against "never ." should fail', async () => {
+	const [actual] = bodyFullStop(await parsed.with, 'never', '.');
+	const expected = false;
+	expect(actual).toEqual(expected);
+});
+
+test('without against "always ." should fail', async () => {
+	const [actual] = bodyFullStop(await parsed.without, 'always', '.');
+	const expected = false;
+	expect(actual).toEqual(expected);
+});
+
+test('without against "never ." should succeed', async () => {
+	const [actual] = bodyFullStop(await parsed.without, 'never', '.');
+	const expected = true;
+	expect(actual).toEqual(expected);
+});

@commitlint/rules/src/body-full-stop.ts

@@ -0,0 +1,22 @@
+import message from '@commitlint/message';
+import {SyncRule} from '@commitlint/types';
+
+export const bodyFullStop: SyncRule<string> = (
+	parsed,
+	when = 'always',
+	value = '.'
+) => {
+	const input = parsed.body;
+
+	if (!input) {
+		return [true];
+	}
+
+	const negated = when === 'never';
+	const hasStop = input[input.length - 1] === value;
+
+	return [
+		negated ? !hasStop : hasStop,
+		message(['body', negated ? 'may not' : 'must', 'end with full stop']),
+	];
+};

@commitlint/rules/src/index.ts

@@ -1,5 +1,6 @@
 import {bodyCase} from './body-case';
 import {bodyEmpty} from './body-empty';
+import {bodyFullStop} from './body-full-stop';
 import {bodyLeadingBlank} from './body-leading-blank';
 import {bodyMaxLength} from './body-max-length';
 import {bodyMaxLineLength} from './body-max-line-length';
@@ -34,6 +35,7 @@ import {typeMinLength} from './type-min-length';
 export default {
 	'body-case': bodyCase,
 	'body-empty': bodyEmpty,
+	'body-full-stop': bodyFullStop,
 	'body-leading-blank': bodyLeadingBlank,
 	'body-max-length': bodyMaxLength,
 	'body-max-line-length': bodyMaxLineLength,

@commitlint/types/src/rules.ts

@@ -91,6 +91,7 @@ export type EnumRuleConfig<V = RuleConfigQuality.User> = RuleConfig<
 export type RulesConfig<V = RuleConfigQuality.User> = {
 	'body-case': CaseRuleConfig<V>;
 	'body-empty': RuleConfig<V>;
+	'body-full-stop': RuleConfig<V>;
 	'body-leading-blank': RuleConfig<V>;
 	'body-max-length': LengthRuleConfig<V>;
 	'body-max-line-length': LengthRuleConfig<V>;

docs/reference-rules.md

@@ -42,6 +42,16 @@ Rule configurations are either of type `array` residing on a key with the rule's
 
 ### Available rules
 
+#### body-full-stop
+
+- **condition**: `body` ends with `value`
+- **rule**: `never`
+- **value**
+
+```
+'.'
+```
+
 #### body-leading-blank
 
 - **condition**: `body` begins with blank line