A new rule that makes sure the user have explained the reason of reverting

.gitignore

@@ -2,3 +2,30 @@ node_modules/
 package.json
 package-lock.json
 yarn.lock
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+bld/
+[Bb]in/
+[Oo]bj/
+[Ll]og/
+[Bb]uild/
+_[Bb]uild/
+[Dd]eploy/
+_[Dd]eploy/
+
+# NUNIT
+*.VisualState.xml
+TestResult.xml
+TestResults.xml
+
+# Visual Studio cache files
+# files ending in .cache can be ignored
+*.[Cc]ache
+# but keep track of directories ending in .cache
+!*.[Cc]ache/

commitlint.config.ts

@@ -333,7 +333,9 @@ module.exports = {
         'proper-issue-refs': [RuleStatus.Error, 'always'],
         'too-many-spaces': [RuleStatus.Error, 'always'],
         'commit-hash-alone': [RuleStatus.Error, 'always'],
+        'proper-revert-message': [RuleStatus.Error, 'always'],
     },
+    defaultIgnores: false,
     plugins: [
         // TODO (ideas for more rules):
         // * Detect if paragraphs in body have been cropped too shortly (less than 64 chars), and suggest same auto-wrap command that body-soft-max-line-length suggests, since it unwraps and wraps (both).
@@ -558,6 +560,30 @@ module.exports = {
                         `Please use full URLs instead of #XYZ refs.`
                     ];
                 },
+
+                'proper-revert-message': ({raw}: {raw:any}) => {
+                    let offence = false;
+
+                    let rawStr = convertAnyToString(raw, "raw").trim();
+                    let lineBreakIndex = rawStr.indexOf('\n')
+
+                    if (lineBreakIndex >= 0){
+                        // Extracting bodyStr from rawStr rather than using body directly is a 
+                        // workaround for https://github.com/conventional-changelog/commitlint/issues/3412
+                        let bodyStr = rawStr.substring(lineBreakIndex).trim()
+                        let lines = bodyStr.split('\n');
+                        if (lines.length == 1) {
+                            if (lines[0].match('This reverts commit ') !== null) {
+                                offence = true;
+                            }
+                        }
+                    }
+
+                    return [
+                        !offence,
+                        `Please explain why you're reverting`
+                    ];
+                },  
 
 
                 'too-many-spaces': ({raw}: {raw:any}) => {
@@ -570,6 +596,7 @@ module.exports = {
                         `Please watch out for too many whitespaces in the text`
                     ];
                 },
+
 
                 'type-space-after-colon': ({header}: {header:any}) => {
                     let headerStr = convertAnyToString(header, "header");

commitlintplugins.test.ts

@@ -348,11 +348,29 @@ test('proper-issue-refs3', () => {
     let commitMsgWithHashtagRefInBlock =
         "foo: this is only a title" + "\n\n" + "Bar baz:\n\n```\ntype Foo = string #123\n```";
     let properIssueRefs3 = runCommitLintOnMsg(commitMsgWithHashtagRefInBlock);
-    console.log('HERE =======>' + properIssueRefs3.stdout)
     expect(properIssueRefs3.status).toBe(0);
 });
 
 
+test('proper-revert-message1', () => {
+    let commitMsgWithoutProperRevertMessage = 
+        'Revert "add abbreviations.ts"\n\n' + 
+        'This reverts commit 0272f587c7eece147e8d1756116b0b43e11c34ac.';
+    let properRevertMessage1 = runCommitLintOnMsg(commitMsgWithoutProperRevertMessage);
+    expect(properRevertMessage1.status).not.toBe(0);
+});
+
+
+test('proper-revert-message2', () => {
+    let commitMsgWithProperRevertMessage = 
+        'Revert "add abbreviations.ts"\n\n' + 
+        'This reverts commit 0272f587c7eece147e8d1756116b0b43e11c34ac,\n' +
+        'because/otherwise bla bla.'
+    let properRevertMessage2 = runCommitLintOnMsg(commitMsgWithProperRevertMessage);
+    expect(properRevertMessage2.status).toBe(0);
+});
+
+
 test('subject-lowercase1', () => {
     let commitMsgWithUppercaseAfterColon = "foo: Bar baz";
     let subjectLowerCase1 = runCommitLintOnMsg(commitMsgWithUppercaseAfterColon);